What is diabetes?

Diabetes mellitus is a group of metabolic diseases characterized by high blood sugar (glucose) levels, which result from defects in insulin secretion, or action, or both. Diabetes mellitus, commonly referred to as diabetes (as it will be in this article) was first identified as a disease associated with “sweet urine," and excessive muscle loss in the ancient world. Elevated levels of blood glucose (hyperglycemia) lead to spillage of glucose into the urine, hence the term sweet urine. Normally, blood glucose levels are tightly controlled by insulin, a hormone produced by the pancreas. Insulin lowers the blood glucose level. When the blood glucose elevates (for example, after eating food), insulin is released from the pancreas to normalize the glucose level. In patients with diabetes, the absence or insufficient production of insulin causes hyperglycemia. Diabetes is a chronic medical condition, meaning that although it can be controlled, it lasts a lifetime.

What is the impact of diabetes?

Over time, diabetes can lead to blindness, kidney failure, and nerve damage. These types of damage are the result of damage to small vessels, referred to as microvascular disease. Diabetes is also an important factor in accelerating the hardening and narrowing of the arteries (atherosclerosis), leading to strokes, coronary heart disease, and other large blood vessel diseases. This is referred to as macrovascular disease. Diabetes affects approximately 17 million people (about 8% of the population) in the United States. In addition, an estimated additional 12 million people in the United States have diabetes and don't even know it. From an economic perspective, the total annual cost of diabetes in 1997 was estimated to be 98 billion dollars in the United States. The per capita cost resulting from diabetes in 1997 amounted to $10,071.00; while healthcare costs for people without diabetes incurred a per capita cost of $2,699.00. During this same year, 13.9 million days of hospital stay were attributed to diabetes, while 30.3 million physician office visits were diabetes related. Remember, these numbers reflect only the population in the United States. Globally, the statistics are staggering.

Diabetes is the third leading cause of death in the United States after heart disease and cancer.

What causes diabetes?

Insufficient production of insulin (either absolutely or relative to the body's needs), production of defective insulin (which is uncommon), or the inability of cells to use insulin properly and efficiently leads to hyperglycemia and diabetes. This latter condition affects mostly the cells of muscle and fat tissues, and results in a condition known as "insulin resistance." This is the primary problem in type 2 diabetes. The absolute lack of insulin, usually secondary to a destructive process affecting the insulin producing beta cells in the pancreas, is the main disorder in type 1 diabetes. In type 2 diabetes, there also is a steady decline of beta cells that adds to the process of elevated blood sugars. For more, please read the Insulin Resistance article. Essentially, if someone is resistant to insulin, the body can, to some degree, increase production of insulin and overcome the level of resistance. After time, if production decreases and insulin cannot be released as vigorously, hyperglycemia develops.

Glucose is a simple sugar found in food. Glucose is an essential nutrient that provides energy for the proper functioning of the body cells. Carbohydrates are broken down in the small intestine and the glucose in digested food is then absorbed by the intestinal cells into the bloodstream, and is carried by the bloodstream to all the cells in the body where it is utilized. However, glucose cannot enter the cells alone and needs insulin to aid in its transport into the cells. Without insulin, the cells become starved of glucose energy despite the presence of abundant glucose in the bloodstream. In certain types of diabetes, the cells' inability to utilize glucose gives rise to the ironic situation of "starvation in the midst of plenty". The abundant, unutilized glucose is wastefully excreted in the urine.

Insulin is a hormone that is produced by specialized cells (beta cells) of the pancreas. (The pancreas is a deep-seated organ in the abdomen located behind the stomach.) In addition to helping glucose enter the cells, insulin is also important in tightly regulating the level of glucose in the blood. After a meal, the blood glucose level rises. In response to the increased glucose level, the pancreas normally releases more insulin into the bloodstream to help glucose enter the cells and lower blood glucose levels after a meal. When the blood glucose levels are lowered, the insulin release from the pancreas is turned down. It is important to note that even in the fasting state there is a low steady release of insulin than fluctuates a bit and helps to maintain a steady blood sugar level during fasting. In normal individuals, such a regulatory system helps to keep blood glucose levels in a tightly controlled range. As outlined above, in patients with diabetes, the insulin is either absent, relatively insufficient for the body's needs, or not used properly by the body. All of these factors cause elevated levels of blood glucose (hyperglycemia).

What are the different types of diabetes?

There are two major types of diabetes, called type 1 and type 2. Type 1 diabetes was also called insulin dependent diabetes mellitus (IDDM), or juvenile onset diabetes mellitus. In type 1 diabetes, the pancreas undergoes an autoimmune attack by the body itself, and is rendered incapable of making insulin. Abnormal antibodies have been found in the majority of patients with type 1 diabetes. Antibodies are proteins in the blood that are part of the body's immune system. The patient with type 1 diabetes must rely on insulin medication for survival.

In autoimmune diseases, such as type 1 diabetes, the immune system mistakenly manufactures antibodies and inflammatory cells that are directed against and cause damage to patients' own body tissues. In persons with type 1 diabetes, the beta cells of the pancreas, which are responsible for insulin production, are attacked by the misdirected immune system. It is believed that the tendency to develop abnormal antibodies in type 1 diabetes is, in part, genetically inherited, though the details are not fully understood. Exposure to certain viral infections (mumps and Coxsackie viruses) or other environmental toxins may serve to trigger abnormal antibody responses that cause damage to the pancreas cells where insulin is made. These antibodies can be measured in the majority of patients, and may help determine which individuals are at risk for developing type 1 diabetes.

At present, the American Diabetes Association does not recommend general screening of the population for type 1 diabetes, though screening of high risk individuals, such as those with a first degree relative (sibling or parent) with type 1 diabetes should be encouraged. Type 1 diabetes tends to occur in young, lean individuals, usually before 30 years of age, however, older patients do present with this form of diabetes on occasion. This subgroup is referred to as latent autoimmune diabetes in adults (LADA). LADA is a slow, progressive form of type 1 diabetes. Of all the patients with diabetes, only approximately 10% of the patients have type 1 diabetes and the remaining 90% have type 2 diabetes.

Type 2 diabetes was also referred to as non-insulin dependent diabetes mellitus (NIDDM), or adult onset diabetes mellitus (AODM). In type 2 diabetes, patients can still produce insulin, but do so relatively inadequately for their body’s needs, particularly in the face of insulin resistance as discussed above. In many cases this actually means the pancreas produces larger than normal quantities of insulin. A major feature of type 2 diabetes is a lack of sensitivity to insulin by the cells of the body (particularly fat and muscle cells). In addition to the problems with an increase in insulin resistance, the release of insulin by the pancreas may also be defective and suboptimal. In fact, there is a known steady decline in beta cell production of insulin in type 2 diabetes that contributes to worsening glucose control. (This is a major factor for many patients with type 2 diabetes who ultimately require insulin therapy.) Finally, the liver in these patients continues to produce glucose through a process called gluconeogenesis despite elevated glucose levels. The control of gluconeogenesis becomes compromised.

While it is said that type 2 diabetes occurs mostly in individuals over 30 years old and the incidence increases with age, we are seeing an alarming number patients with type 2 diabetes who are barely in their teen years. In fact, for the first time in the history of humans, type 2 diabetes is now more common than type 1 diabetes in childhood. Most of these cases are a direct result of poor eating habits, higher body weight, and lack of exercise.

While there is a strong genetic component to developing this form of diabetes, there are other risk factors - the most significant of which is obesity. There is a direct relationship between the degree of obesity and the risk of developing type 2 diabetes, and this holds true in children as well as adults. It is estimated that the chance to develop diabetes doubles for every 20% increase over desirable body weight.

Regarding age, data shows that for each decade after 40 years of age regardless of weight there is an increase in incidence of diabetes. The prevalence of diabetes in persons 65 to 74 years of age is nearly 20%. Type 2 diabetes is also more common in certain ethnic groups. Compared with a 6% prevalence in Caucasians, the prevalence in African Americans and Asian Americans is estimated to be 10%, in Hispanics 15%, and in certain Native American communities 20% to 50%. Finally, diabetes occurs much more frequently in women with a prior history of diabetes that develops during pregnancy (gestational diabetes - see below).

Diabetes can occur temporarily during pregnancy. Significant hormonal changes during pregnancy can lead to blood sugar elevation in genetically predisposed individuals. Blood sugar elevation during pregnancy is called gestational diabetes. Gestational diabetes usually resolves once the baby is born. However, 25-50% of women with gestational diabetes will eventually develop Type 2 diabetes later in life, especially in those who require insulin during pregnancy and those who remain overweight after their delivery. Patients with gestational diabetes are usually asked to undergo an oral glucose tolerance test about 6 weeks after giving birth to determine if their diabetes has persisted beyond the pregnancy, or if any evidence (such as impaired glucose tolerance) is present that may be a clue to the patient’s future risk for developing diabetes.

"Secondary" diabetes refers to elevated blood sugar levels from another medical condition. Secondary diabetes may develop when the pancreatic tissue responsible for the production of insulin is destroyed by disease, such as chronic pancreatitis (inflammation of the pancreas by toxins like excessive alcohol), trauma, or surgical removal of the pancreas. Diabetes can also result from other hormonal disturbances, such as excessive growth hormone production (acromegaly) and Cushing's syndrome. In acromegaly, a pituitary gland tumor at the base of the brain causes excessive production of growth hormone, leading to hyperglycemia. In Cushing's syndrome, the adrenal glands produce an excess of cortisol, which promotes blood sugar elevation.

In addition, certain medications may worsen diabetes control, or "unmask" latent diabetes. This is seen most commonly when steroid medications (such as prednisone) are taken and also with medications used in the treatment of HIV infection (AIDS).

What are diabetes symptoms?

The early symptoms of untreated diabetes are related to elevated blood sugar levels, and loss of glucose in the urine. High amounts of glucose in the urine can cause increased urine output and lead to dehydration. Dehydration causes increased thirst and water consumption. The inability of insulin to perform normally has effects on protein, fat and carbohydrate metabolism. Insulin is an anabolic hormone, that is, one that encourages storage of fat and protein. A relative or absolute insulin deficiency eventually leads to weight loss despite an increase in appetite. Some untreated diabetes patients also complain of fatigue, nausea and vomiting. Patients with diabetes are prone to developing infections of the bladder, skin, and vaginal areas. Fluctuations in blood glucose levels can lead to blurred vision. Extremely elevated glucose levels can lead to lethargy and coma.

How is diabetes diagnosed?

The fasting blood glucose (sugar) test is the preferred way to diagnose diabetes. It is easy to perform and convenient. After the person has fasted overnight (at least 8 hours), a single sample of blood is drawn and sent to the laboratory for analysis. This can also be done accurately in a doctor’s office using a glucose meter.

Normal fasting plasma glucose levels are less than 100 milligrams per deciliter (mg/dl). Fasting plasma glucose levels of more than 126 mg/dl on two or more tests on different days indicate diabetes. A random blood glucose test can also be used to diagnose diabetes A blood glucose level of 200 mg/dl or higher indicates diabetes.

When fasting blood glucose stays above 100mg/dl, but in the range of 100-126mg/dl, this is known as impaired fasting glucose (IFG). While patients with IFG do not have the diagnosis of diabetes, this condition carries with it its own risks and concerns, and is addressed elsewhere.

The oral glucose tolerance test

Though not routinely used anymore, the oral glucose tolerance test (OGTT) is a gold standard for making the diagnosis of type 2 diabetes. It is still commonly used for diagnosing gestational diabetes. With an oral glucose tolerance test, the person fasts overnight (at least eight but not more than 16 hours). Then first, the fasting plasma glucose is tested. After this test, the person receives 75 grams of glucose (100 grams for pregnant women). There are several methods employed by obstetricians to do this test, but the one described here is standard. Usually, the glucose is in a sweet-tasting liquid that the person drinks. Blood samples are taken at specific intervals to measure the blood glucose.

For the test to give reliable results, the person must be in good health (not have any other illnesses, not even a cold). Also, the person should be normally active (not lying down, for example, as an inpatient in a hospital) and should not be taking medicines that could affect the blood glucose. For three days before the test, the person should have eaten a diet high in carbohydrates (150- 200 grams per day). The morning of the test, the person should not smoke or drink coffee.

The classic oral glucose tolerance test measures blood glucose levels five times over a period of three hours. Some physicians simply get a baseline blood sample followed by a sample two hours after drinking the glucose solution. In a person without diabetes, the glucose levels rise and then fall quickly. In someone with diabetes, glucose levels rise higher than normal and fail to come back down as fast.

People with glucose levels between normal and diabetic have impaired glucose tolerance (IGT). People with impaired glucose tolerance do not have diabetes, but are at high risk for progressing to diabetes. Each year, 1-5% of people whose test results show impaired glucose tolerance actually eventually develop diabetes. Weight loss and exercise may help people with impaired glucose tolerance return their glucose levels to normal. In addition, some physicians advocate the use of medications, such as metformin (Glucophage), to help prevent/delay the onset of overt diabetes. Recent studies have shown that impaired glucose tolerance itself may be a risk factor for the development of heart disease. In the medical community, most physicians are now understanding that impaired glucose tolerance is nor simply a precursor of diabetes, but is its own clinical disease entity that requires treatment and monitoring.

Evaluating the results of the oral glucose tolerance test

Glucose tolerance tests may lead to one of the following diagnoses:

• Normal response: A person is said to have a normal response when the 2-hour glucose level is less than 140 mg/dl, and all values between 0 and 2 hours are less than 200 mg/dl.
• Impaired glucose tolerance: A person is said to have impaired glucose tolerance when the fasting plasma glucose is less than 126 mg/dl and the 2-hour glucose level is between 140 and 199 mg/dl.
• Diabetes: A person has diabetes when two diagnostic tests done on different days show that the blood glucose level is high.
• Gestational diabetes: A woman has gestational diabetes when she has any two of the following: a 100g OGTT, a fasting plasma glucose of more than 95 mg/dl, a 1-hour glucose level of more than 180 mg/dl, a 2-hour glucose level of more than 155 mg/dl, or a 3-hour glucose level of more than 140 mg/dl.

Why is blood sugar checked at home?

Home blood sugar (glucose) testing is an important part of controlling blood sugar. One important goal of diabetes treatment is to keep the blood glucose levels near the normal range of 70 to 120 mg/dl before meals and under 140 mg/dl at two hours after eating. Blood glucose levels are usually tested before and after meals, and at bedtime. The blood sugar level is typically determined by pricking a fingertip with a lancing device and applying the blood to a glucose meter, which reads the value. There are many meters on the market, for example, Accu-Check Advantage, One Touch Ultra, Sure Step and Freestyle. Each meter has its own advantages and disadvantages (some use less blood, some have a larger digital readout, some take a shorter time to give you results, etc). The test results are then used to help patients make adjustments in medications, diets, and physical activities.

There are some interesting developments in blood glucose monitoring. Currently, at least three continuous glucose sensors are being considered for approval in the United States (Dexcom, Medtronic and Navigator). The new continuous glucose sensor systems involve an implantable cannula placed just under the skin in the abdomen or in the arm. This cannula allows for frequent sampling of blood glucose levels. Attached to this is a transmitter that sends the data to a pager-like device. This device has a visual screen that allows the wearer to see, not only the current glucose reading, but also the graphic trends. In some devices, the rate of change of blood sugar is also shown. There are alarms for low and high sugar levels. Certain models will alarm if the rate of change indicates the wearer is at risk for dropping or rising blood glucose too rapidly. The Medtronic version is specifically designed to interface with their insulin pumps. However, at this time the patient still must manually approve any insulin dose (the pump cannot blindly respond to the glucose information it receives, it can only give a calculated suggestion as to whether the wearer should give insulin, and if so, how much). All of these devices need to be correlated to fingersticks for a few hours before they can function independently. The devices can then provide readings for 3-5 days.

Diabetes experts feel that these blood glucose monitoring devices give patients a significant amount of independence to manage their disease process; and they are a great tool for education as well. It is also important to remember that these devices can be used intermittently with fingersticks. For example, a well-controlled patient with diabetes can rely on fingerstick glucose checks a few times a day and do well. If they become ill, if they decide to embark on a new exercise regimen, if they change their diet and so on, they can use the sensor to supplement their fingerstick regimen, providing more information on how they are responding to new lifestyle changes or stressors. This kind of system takes us one step closer to closing the loop, and to the development of an artifical pancreas that senses insulin requirements based on glucose levels and the body’s needs and releases insulin accordingly - the ultimate goal.

Hemoglobin A1c (A1c)

To explain what an A1c is, think in simple terms. Sugar sticks, and when it's around for a long time, it's harder to get it off. In the body, sugar sticks too, particularly to proteins. The red blood cells that circulate in the body live for about three months before they die off. When sugar sticks to these cells, it gives us an idea of how much sugar is around for the preceding three months. In most labs, the normal range is 4-5.9 %. In poorly controlled diabetes, its 8.0% or above, and in well controlled patients it's less than 7.0% (optimal is <6.5%). The benefits of measuring A1c is that is gives a more reasonable and stable view of what's happening over the course of time (three months), and the value does not bounce as much as finger stick blood sugar measurements. There is a direct correlation between A1c levels and average blood sugar levels as follows.

While there are no guidelines to use A1c as a screening tool, it gives a physician a good idea that someone is diabetic if the value is elevated. Right now, it is used as a standard tool to determine blood sugar control in patients known to have diabetes.

The American Diabetes Association currently recommends an A1c goal of less than 7.0%. Other Groups such as the American Association of Clinical Endocrinologists feel that an A1c of < 6.5% should be the goal.

Of interest, studies have shown that there is about a 10% decrease in relative risk for microvascular disease for every 1 % reduction in A1c. So, if a patient starts off with an A1c of 10.7 and drops to 8.2, though there are not yet at goal, they have managed to decrease their risk of microvascular complications by about 20%. The closer to normal the A1c, the lower the absolute risk for microvascular complications. Data also suggests that the risk of macrovascular disease decreases by about 24% for every 1% reduction in A1c values.

It should be mentioned here that there are a number of conditions in which an A1c value may not be accurate. For example, with significant anemia, the red blood cell count is low, and thus the A1c is falsely low as is similarly in cases of sickle cell disease and other hemoglobinopathies. For more, please read the Hemoglobin A1c article.

 What are the acute complications of diabetes?

1. Severely elevated blood sugar levels due to an actual lack of insulin or a relative deficiency of insulin.
2. Abnormally low blood sugar levels due to too much insulin or other glucose-lowering medications.

Insulin is vital to patients with type 1 diabetes - they cannot live with out a source of exogenous insulin. Without insulin, patients with type 1 diabetes develop severely elevated blood sugar levels. This leads to increased urine glucose, which in turn leads to excessive loss of fluid and electrolytes in the urine. Lack of insulin also causes the inability to store fat and protein along with breakdown of existing fat and protein stores. This dysregulation, results in the process of ketosis and the release of ketones into the blood. Ketones turn the blood acidic, a condition called diabetic ketoacidosis (DKA). Symptoms of diabetic ketoacidosis include nausea, vomiting, and abdominal pain. Without prompt medical treatment, patients with diabetic ketoacidosis can rapidly go into shock, coma, and even death.

Diabetic ketoacidosis can be caused by infections, stress, or trauma all which may increase insulin requirements. In addition, missing doses of insulin is also an obvious risk factor for developing diabetic ketoacidosis. Urgent treatment of diabetic ketoacidosis involves the intravenous administration of fluid, electrolytes, and insulin, usually in a hospital intensive care unit. Dehydration can be very severe, and it is not unusual to need to replace 6-7 liters of fluid when a person presents in diabetic ketoacidosis. Antibiotics are given for infections. With treatment, abnormal blood sugar levels, ketone production, acidosis, and dehydration can be reversed rapidly, and patients can recover remarkably well.

In patients with type 2 diabetes, stress, infection, and medications (such as corticosteroids) can also lead to severely elevated blood sugar levels. Accompanied by dehydration, severe blood sugar elevation in patients with type 2 diabetes can lead to an increase in blood osmolality (hyperosmolar state). This condition can lead to coma (hyperosmolar coma). A hyperosmolar coma usually occurs in elderly patients with type 2 diabetes. Like diabetic ketoacidosis, a hyperosmolar coma is a medical emergency. Immediate treatment with intravenous fluid and insulin is important in reversing the hyperosmolar state. Unlike patients with type 1 diabetes, patients with type 2 diabetes do not generally develop ketoacidosis solely on the basis of their diabetes. Since in general, type 2 diabetes occurs in an older population, concomitant medical conditions are more likely to exist, and these patients may actually be sicker overall. The complication and death rates from hyperosmolar coma is thus higher than in DKA.

Hypoglycemia means abnormally low blood sugar (glucose). In patients with diabetes, the most common cause of low blood sugar is excessive use of insulin or other glucose-lowering medications, to lower the blood sugar level in diabetic patients in the presence of a delayed or absent meal. When low blood sugar levels occur because of too much insulin, it is called an insulin reaction. Sometimes, low blood sugar can be the result of an insufficient caloric intake or sudden excessive physical exertion.

Blood glucose is essential for the proper functioning of brain cells. Therefore, low blood sugar can lead to central nervous system symptoms such as dizziness, confusion, weakness, and tremors. The actual level of blood sugar at which these symptoms occur varies with each person, but usually it occurs when blood sugars are less than 65 mg/dl. Untreated, severely low blood sugar levels can lead to coma, seizures, and, in the worse case scenario, irreversible brain death. At this point, the brain is suffering from a lack of sugar, and this usually occurs somewhere around levels of <40 mg/dl.

The treatment of low blood sugar consists of administering a quickly absorbed glucose source. These include glucose containing drinks, such as orange juice, soft drinks (not sugar-free), or glucose tablets in doses of 15-20 grams at a time (for example, the equivalent of half a glass of juice). Even cake frosting applied inside the cheeks can work in a pinch if patient cooperation is difficult. If the individual becomes unconscious, glucagon can be given by intramuscular injection.

Glucagon causes the release of glucose from the liver (i.e., it promotes gluconeogenesis). Glucagon can be lifesaving and every patient with diabetes who has a history of hypoglycemia (particularly those on insulin) should have a glucagon kit. Families and friends of those with diabetes need to be taught how to administer glucagon, since obviously the patients will not be able to do it themselves in an emergency situation. Another lifesaving device that should be mentioned is very simple; a medic alert bracelet should be worn by all patients with diabetes

What are the chronic complications of diabetes?

These diabetes complications are related to blood vessel diseases and are generally classified into small vessel disease, such as those involving the eyes, kidneys and nerves (microvascular disease), and large vessel disease involving the heart and blood vessels (macrovascular disease). Diabetes accelerates hardening of the arteries (atherosclerosis) of the larger blood vessels, leading to coronary heart disease (angina or heart attack), strokes, and pain in the lower extremities because of lack of blood supply (claudication). For more information, please read the following articles: Stroke, Angina, and Heart Attack.

Eye Complications

The major eye complication of diabetes is called diabetic retinopathy. Diabetic retinopathy occurs in patients who have had diabetes for at least five years. Diseased small blood vessels in the back of the eye cause the leakage of protein and blood in the retina. Disease in these blood vessels also causes the formation of small aneurysms (microaneurysms), and new but brittle blood vessels (neovascularization). Spontaneous bleeding from the new and brittle blood vessels can lead to retinal scarring and retinal detachment, thus impairing vision.

To treat diabetic retinopathy a laser is used to destroy and prevent the recurrence of the development of these small aneurysms and brittle blood vessels. Approximately 50% of patients with diabetes will develop some degree of diabetic retinopathy after 10 years of diabetes, and 80% of diabetics have retinopathy after 15 years of the disease. Poor control of blood sugar and blood pressure further aggravates eye disease in diabetes. For more, please read the Diabetic Eye Disease article.

Cataracts and glaucoma are also more common among diabetics. It is also important to note that since the lens of the eye lets water through, if blood sugar concentrations vary a lot, the lens of the eye will shrink and swell with fluid accordingly. As a result, blurry vision is very common in poorly controlled diabetes. Patients are usually discouraged from getting a new eyeglass prescription until their blood sugar is controlled. This allows for a more accurate assessment of what kind of glasses prescription is required.

Kidney damage

Kidney damage from diabetes is called diabetic nephropathy. The onset of kidney disease and its progression is extremely variable. Initially, diseased small blood vessels in the kidneys cause the leakage of protein in the urine. Later on, the kidneys lose their ability to cleanse and filter blood. The accumulation of toxic waste products in the blood leads to the need for dialysis. Dialysis involves using a machine that serves the function of the kidney by filtering and cleaning the blood. In patients who do not want to undergo chronic dialysis, kidney transplantation can be considered. For more about dialysis, please read the Kidney Dialysis article.

The progression of nephropathy in patients can be significantly slowed by controlling high blood pressure, and by aggressively treating high blood sugar levels. Angiotensin converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers (ARBs) used in treating high blood pressure may also benefit kidney disease in diabetic patients.

Nerve damage

Nerve damage in diabetes is called diabetic neuropathy and is also caused by disease of small blood vessels. In essence, the blood flow to the nerves is limited, leaving the nerves without blood flow, and they get damaged or die as a result (a term known as ischemia). Symptoms of diabetic nerve damage include numbness, burning, and aching of the feet and lower extremities. When the nerve disease causes a complete loss of sensation in the feet, patients may not be aware of injuries to the feet, and fail to properly protect them. Shoes or other protection should be worn as much as possible. Seemingly minor skin injuries should be attended to promptly to avoid serious infections. Because of poor blood circulation, diabetic foot injuries may not heal. Sometimes, minor foot injuries can lead to serious infection, ulcers, and even gangrene, necessitating surgical amputation of toes, feet, and other infected parts.

Diabetic nerve damage can affect the nerves that are important for penile erection, causing erectile dysfunction (ED, impotence). Erectile dysfunction can also be caused by poor blood flow to the penis from diabetic blood vessel disease.

Diabetic neuropathy can also affect nerves to the stomach and intestines, causing nausea, weight loss, diarrhea, and other symptoms of gastroparesis (delayed emptying of food contents from the stomach into the intestines, due to ineffective contraction of the stomach muscles).

The pain of diabetic nerve damage may respond to traditional treatments with gabapentin (Neurontin), phenytoin (Dilantin), carbamazepine (Tegretol), desipramine (Norpraminine), amitriptyline (Elavil), or with topically-applied capsaicin (an extract of pepper). Neurontin, Dilantin and Tegretol are medications that are traditionally used in the treatment of seizure disorders. Elavil and Norpraminine are medications that are traditionally used for depression. While many of these medications are not FDA indicated specifically for the treatment of diabetes related nerve pain, they are used by physicians commonly. The pain of diabetic nerve damage may also improve with better blood sugar control, though unfortunately blood glucose control and the course of neuropathy do not always go hand in hand. Newer medications for nerve pain have recently come to market in the US. Pregabalin (Lyrica) which has an indication for diabetic neuropathic pain and  duloxetine (Cymbalta) are newer agents used in the treatment of diabetic neuropathy

What can be done to slow diabetes complications?

Findings from the Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) have clearly shown that aggressive and intensive control of elevated levels of blood sugar in patients with type 1 and type 2 diabetes decreases the complications of nephropathy, neuropathy, retinopathy, and may reduce the occurrence and severity of large blood vessel diseases. Aggressive control with intensive therapy means achieving fasting glucose levels between 70-120 mg/dl; glucose levels of less than 160 mg/dl after meals; and a near normal hemoglobin A1C levels (see below).

Studies in type 1 patients have shown that in intensively treated patients, diabetic eye disease decreased by 76%, kidney disease decreased by 54%, and nerve disease decreased by 60%. More recently the EDIC trial has shown that type 1 diabetes is also associated with increased heart disease, similar to type 2 diabetes. However, the price for aggressive blood sugar control is a two to three fold increase in the incidence of abnormally low blood sugar levels (caused by the diabetes medications). For this reason, tight control of diabetes to achieve glucose levels between 70-120 mg/dl is not recommended for children under 13 years of age, patients with severe recurrent hypoglycemia, patients unaware of their hypoglycemia, and patients with far advanced diabetes complications. To achieve optimal glucose control without an undue risk of abnormally lowering blood sugar levels, patients with type 1 diabetes must monitor their blood glucose at least four times a day and administer insulin at least three times per day. In patients with type 2 diabetes, aggressive blood sugar control has similar beneficial effects on the eyes, kidneys, nerves and blood vessels.

The future of pancreas transplantation

Ultimately, the goal in the management of type 1 diabetes is to provide insulin therapy in a manner that mimics the natural pancreas. Perhaps the closest therapy available at this time is a transplant of the pancreas. Several approaches to pancreatic transplantation are currently being studied, including the whole pancreas and isolated islet cells (these groups of cells contain beta cells that are responsible for insulin production). Data available from 1995 indicates that almost 8,000 patients underwent pancreatic transplantation. Most patients undergo pancreatic transplantation at the time of kidney transplantation for diabetic kidney disease.

Transplantation is not without risk. Both the surgery itself and the immunosuppression that must occur afterward pose significant risks to the patient. For these reasons, the kidney and pancreas are usually transplanted at the same time. At present, there is disagreement about whole pancreas transplantation in patients not currently requiring kidney transplantation. The issue of whether the benefits outweigh the risks in these patients is under debate. There is also a chance that diabetes will occur in the transplanted pancreas. Selectively transplanting islet cells is an interesting alternative to whole pancreas transplantation. However, the concern over rejection remains. Attempts to disguise the islet cells in tissues that the body won't reject (for example, by surrounding the islet cells by the patient's own cells and then implanting them) are underway. In addition, researchers are exploring artificial barriers that can surround the islet cells, provide protection against rejection, and still allow insulin to enter the bloodstream.

A Final Word

These last few years have been an exciting time in diabetes care. Many agents for the treatment of type 2 diabetes are under development and the options for insulin therapy continue to grow and methods for insulin delivery continue to become more refined. While research continues to expand in these areas, one thing remains constant. Achieving the best blood sugar control possible remains the ultimate goal in both type 1 and type 2 diabetes. We now know, beyond a doubt, that good blood sugar control minimizes the long-term complications of diabetes, including blindness, nerve damage, and kidney damage. Finally, a healthy lifestyle can do nothing bad...it should remain the cornerstone of management for diabetes.

Diabetes At A Glance

• Diabetes is a chronic condition associated with abnormally high levels of sugar (glucose) in the blood.
• Insulin produced by the pancreas lowers blood glucose.
• Absence or insufficient production of insulin causes diabetes.
• The two types of diabetes are referred to as type 1 (insulin dependent) and type 2 (non-insulin dependent).
• Symptoms of diabetes include increased urine output, thirst and hunger as well as fatigue.
• Diabetes is diagnosed by blood sugar (glucose) testing.
• The major complications of diabetes are both acute and chronic.
  • Acutely: dangerously elevated blood sugar, abnormally low blood sugar due to diabetes medications may occur.
  • Chronically: disease of the blood vessels (both small and large) which can damage the eye, kidneys, nerves, and heart may occur
• Diabetes treatment depends on the type and severity of the diabetes. Type 1 diabetes is treated with insulin, exercise, and a diabetic diet. Type 2 diabetes is first treated with weight reduction, a diabetic diet, and exercise. When these measures fail to control the elevated blood sugars, oral medications are used. If oral medications are still insufficient, insulin medications are considered.

How Food Affects Your Blood Glucose

Whether you have type 1 or type 2 , what, when, and how much you eat all affect your blood glucose . Blood glucose is the main sugar found in the blood and the body's main source of energy.

If you have diabetes (or impaired glucose tolerance), your blood glucose can go too high if you eat too much. If your blood glucose goes too high, you can get sick.

Your blood glucose can also go too high or drop too low if you don't take the right amount of diabetes medicine.

If your blood glucose stays high too much of the time, you can get heart, eye, foot, kidney, and other problems. You can also have problems if your blood glucose gets too low (hypoglycemia).

Keeping your blood glucose at a healthy level will prevent or slow down diabetes problems. Ask your doctor or diabetes teacher what a healthy blood glucose level is for you.

Blood Glucose Levels

What should my blood glucose levels be?

For most people, target blood glucose levels are

Time of Test	Goal plasma glucose
Before meals	90-130 mg/dL (milligrams per deciliter)
Before bedtime snack (1-2 hours after a meal/postprandial)	less than 180mg/dL
Every three months HgA1c	less than 7%

*Source: American Diabetes Association, 2003

For women with gestational diabetes, experts recommend the following goals for diabetes management:

• A fasting glucose less than 105 mg/dL (plasma) or less than 95 mg/dL (whole blood)
• A 2 hour post meal less than 130mg/dL (plasma) or less than 120 md/dL (whole blood)

Talk with your health care provider about your blood glucose target levels. Print out this chart and write them in.

Before meals ______ to ______ 1 to 2 hours after the start of a meal less than ______

Ask your doctor how often you should check your blood glucose. The results from your blood glucose checks will tell you if your diabetes care plan is working. Also ask your doctor for an A1C test at least twice a year. Your A1C number gives your average blood glucose for the past 3 months.

How can I keep my blood glucose at a healthy level?

• Eat about the same amount of food each day.
  
• Eat your meals and snacks at about the same times each day.
  
• Do not skip meals or snacks.
  
• Take your medicines at the same times each day.
  
• Exercise at about the same times each day.

Why should I eat about the same amount at the same times each day?

Your blood glucose goes up after you eat. If you eat a big lunch one day and a small lunch the next day, your blood glucose levels will change too much.

Keep your blood glucose at a healthy level by eating about the same amount of carbohydrate foods at about the same times each day. Carbohydrate foods, also called carbs, provide glucose for energy. Starches, fruits, milk, starchy vegetables such as corn, and sweets are all carbohydrate foods.

Talk with your doctor or diabetes teacher about how many meals and snacks to eat each day. Print out these clock faces and draw hands on the clocks to show when to have your meals and, if necessary, snacks.

Your Diabetes Medicines

What you eat and when affects how your diabetes medicines work. Talk with your doctor or diabetes teacher about the best times to take your diabetes medicines based on your meal plan.

Print out this chart. Fill in the names of your medicines, when to take them, and how much to take. If you take your medicine with a meal, write down the name of the meal. Draw hands on the clocks to show when to take your medicines.

	Name of medicine: __________________ Time: ________ Meal: _______________ How much: ________________________
	Name of medicine: __________________ Time: ________ Meal: _______________ How much: ________________________
	Name of medicine: __________________ Time: ________ Meal: _______________ How much: ________________________
	Name of medicine: __________________ Time: ________ Meal: _______________ How much: ________________________

Your Exercise Plan

What you eat and when also depend on how much you exercise. Exercise is an important part of staying healthy and controlling your blood glucose. Physical activity should be safe and enjoyable, so talk with your doctor about what types of exercise are right for you. Whatever kind of exercise you do, here are some special things that people with diabetes need to remember:

• Take care of your feet. Make sure your shoes fit properly and your socks stay clean and dry. Check your feet for redness or sores after exercising. Call your doctor if you have sores that do not heal.
  
• Drink about 2 cups of water before you exercise, about every 20 minutes during exercise, and after you finish, even if you don't feel thirsty.
  
• Warm up and cool down for 5 to 10 minutes before and after exercising. For example, walk slowly at first, then walk faster. Finish up by walking slowly again.
  
• Test your blood glucose before and after exercising. Do not exercise if your fasting blood glucose level is above 300. Eat a small snack if your blood glucose is below 100.
  
• Know the signs of low blood glucose (hypoglycemia) and how to treat it.

Hypoglycemia

You should know the signs of hypoglycemia (low blood sugar) such as feeling weak or dizzy, sweating more, noticing sudden changes in your heartbeat, or feeling hungry. If you experience these symptoms, stop exercising and test your blood glucose. If it is 70 or less, eat one of the following right away:

• 2 or 3 glucose tablets
  
• 1/2 cup (4 ounces) of any fruit juice
  
• 1/2 cup (4 ounces) of a regular (not diet) soft drink
  
• 1 cup (8 ounces) of milk
  
• 5 or 6 pieces of hard candy
  
• 1 or 2 teaspoons of sugar or honey

After 15 minutes, test your blood glucose again to find out whether it has returned to a healthier level. Once blood glucose is stable, if it will be at least an hour before your next meal, it's a good idea to eat a snack.

To be safe when you exercise, carry something to treat hypoglycemia, such as glucose tablets or hard candy. Another good idea is to wear a medical identification bracelet or necklace (in case of emergency). Teach your exercise partners the signs of hypoglycemia and what to do about it.

The Food Pyramid

Eat a variety of food to get the vitamins and minerals you need. Eat more from the groups at the bottom of the pyramid, and less from the groups at the top.

How much should I eat each day?

Have about 1,200 to 1,600 calories a day if you are

• a small woman who exercises
• a small or medium woman who wants to lose weight
• a medium woman who does not exercise much

Choose this many servings from these food groups to have 1,200 to 1,600 calories a day: 6 starches 2 milk and yogurt 3 vegetables 2 meat or meat substitute 2 fruit up to 3 fats

Talk with your diabetes teacher to make a meal plan that fits the way you usually eat, your daily routine, and your diabetes medicines. Then make your own plan.

Have about 1,600 to 2,000 calories a day if you are

• a large woman who wants to lose weight
• a small man at a healthy weight
• a medium man who does not exercise much
• a medium to large man who wants to lose weight

Choose this many servings from these food groups to have 1,600 to 2,000 calories a day: 8 starches 2 milk and yogurt 4 vegetables 2 meat or meat substitute 3 fruit up to 4 fats

Talk with your diabetes teacher to make a meal plan that fits the way you usually eat, your daily routine, and your diabetes medicines. Then make your own plan.

Have about 2,000 to 2,400 calories a day if you are

• a medium to large man who does a lot of exercise or has a physically active job
• a large man at a healthy weight
• a large woman who exercises a lot or has a physically active job

Choose this many servings from these food groups to have 2,000 to 2,400 calories a day: 11 starches 2 milk and yogurt 4 vegetables 2 meat or meat substitute 3 fruit up to 5 fats

Talk with your diabetes teacher to make a meal plan that fits the way you usually eat, your daily routine, and your diabetes medicines. Then make your own plan.

Make Your Own Food Pyramid

Print out this pyramid and fill in the numbers of servings next to the name of each food group.

Each day, I need

Starches

Starches are bread, grains, cereal, pasta, or starchy vegetables like corn and potatoes. They give your body energy, vitamins, minerals, and fiber. Whole grain starches are healthier because they have more vitamins, minerals, and fiber.

Eat some starches at each meal. People might tell you not to eat starches, but that is not correct. Eating starches is healthy for everyone, including people with diabetes.

Examples of starches include

bread pasta corn

potatoes rice crackers

tortillas beans yams

How much is a serving of starch?

If you have more than one serving at a meal, you can choose several different starches or have two or three servings of one starch.

Print out this chart. Then fill in the blanks with how many servings of starch to have at meals and snacks.

1. How many servings of grains, cereals, pasta, and starchy vegetables (starches) do you now eat each day? I eat _____ starch servings each day.

2. Check how many servings of starches to have each day in the section on "How much should I eat each day.
I will eat _____ starch servings each day.

To control your blood glucose, spread the servings you eat throughout the day.

3. I will eat this many servings of starches at

A diabetes teacher can help you with your meal plan.

What are healthy ways to eat starches?

• Buy whole grain breads and cereals.
  
• Eat fewer fried and high-fat starches such as regular tortilla chips and potato chips, french fries, pastries, or biscuits. Try pretzels, fat-free popcorn, baked tortilla or potato chips, baked potatoes, or low-fat muffins.
  
• Use low-fat or fat-free yogurt or fat-free sour cream instead of regular sour cream on a baked potato.
  
• Use mustard instead of mayonnaise on a sandwich.
  
• Use the low-fat or fat-free substitutes such as low-fat mayonnaise or light margarine on bread, rolls, or toast.
  
• Eat cereal with fat-free (skim) or low-fat (1%) milk.

Vegetables

Vegetables give you vitamins, minerals, and fiber, with very few calories.

Examples of vegetables include

How much is a serving of vegetables?

If you have more than one serving at a meal, you can choose a few different types of vegetables or have two or three servings of one vegetable.

Print out this chart. Then fill in the blanks with how many servings of vegetables to have at meals and snacks.

What are healthy ways to eat vegetables?

• Eat raw and cooked vegetables with little or no fat, sauces, or dressings.
  
• Try low-fat or fat-free salad dressing on raw vegetables or salads.
  
• Steam vegetables using a small amount of water or low-fat broth.
  
• Mix in some chopped onion or garlic.
  
• Use a little vinegar or some lemon or lime juice.
  
• Add a small piece of lean ham or smoked turkey instead of fat to vegetables when cooking.
  
• Sprinkle with herbs and spices. These flavorings add almost no fat or calories.
  
• If you do use a small amount of fat, use canola oil, olive oil, or soft margarines (liquid or tub types) instead of fat from meat, butter, or shortening.

Fruit

Fruit gives you energy, vitamins, minerals, and fiber.

Examples of fruit include

How much is a serving of fruit?

If you have more than one serving at a meal, you can choose different types of fruit or have two servings of one fruit.

Print out this chart. Then fill in the blanks with how many servings of fruit to have at meals and snacks.

What are healthy ways to eat fruit?

• Eat fruits raw or cooked, as juice with no sugar added, canned in their own juice, or dried.
  
• Buy smaller pieces of fruit.
  
• Eat pieces of fruit rather than drinking fruit juice. Pieces of fruit are more filling.
  
• Drink fruit juice in small amounts.
  
• Save high-sugar and high-fat fruit desserts such as peach cobbler or cherry pie for special occasions.

Milk and Yogurt

Milk and yogurt give you energy, protein, fat, calcium, vitamin A, and other vitamins and minerals.

How much is a serving of milk and yogurt?

Note: If you are pregnant or breastfeeding, have four to five servings of milk and yogurt each day.

Print out this chart. Then fill in the blanks with how many servings of milk and yogurt to have at meals and snacks.

What are healthy ways to have milk and yogurt?

• Drink fat-free (skim or nonfat) or low-fat (1%) milk.
  
• Eat low-fat or fat-free fruit yogurt sweetened with a low-calorie sweetener.
  
• Use low-fat plain yogurt as a substitute for sour cream.

Meat and Meat Substitutes

The meat and meat substitutes group includes meat, poultry, eggs, cheese, fish, and tofu. Eat small amounts of some of these foods each day.

Meat and meat substitutes help your body build tissue and muscles. They also give your body energy and vitamins and minerals.

Examples of meat and meat substitutes include

How much is a serving of meat or meat substitute?

*Two to three ounces of meat (after cooking) is about the size of a deck of cards.

Print out this chart. Then fill in the blanks with how many servings of meat and meat substitutes to have at meals and snacks.

What are healthy ways to eat meat or meat substitutes?

• Buy cuts of beef, pork, ham, and lamb that have only a little fat on them. Trim off extra fat.
  
• Eat chicken or turkey without the skin.
  
• Cook meat or meat substitutes in low-fat ways:
  • broil
  • grill
  • stir-fry
  • roast
  • steam
  • stew
    
• To add more flavor, use vinegars, lemon juice, soy or teriyaki sauce, salsa, ketchup, barbecue sauce, and herbs and spices.
  
• Cook eggs with a small amount of fat or use cooking spray.
  
• Limit the amounts of nuts, peanut butter, and fried chicken that you eat. They are high in fat.
  
• Choose low-fat or fat-free cheese.

Fats and Sweets

Limit the amounts of fats and sweets you eat. They have calories, but not much nutrition. Some contain saturated fats and cholesterol that increase your risk of heart disease. Limiting these foods will help you lose weight and keep your blood glucose and blood fats under control.

Examples of fats include

Examples of sweets include

How much is a serving of sweets?

How much is a serving of fat?

How can I satisfy my sweet tooth?

It's okay to have sweets once in a while. Try having sugar-free popsicles, diet soda, fat-free ice cream or frozen yogurt, or sugar-free hot cocoa mix.

Other tips:

• Share desserts in restaurants.
  
• Order small or child-size servings of ice cream or frozen yogurt.
  
• Divide homemade desserts into small servings and wrap each individually. Freeze extra servings.
  
• Don't keep dishes of candy in the house or at work.

Remember, fat-free and low-sugar foods still have calories. Talk with your diabetes teacher about how to fit sweets into your meal plan.

Alcohol

Alcohol has calories but no nutrients. If you drink alcohol on an empty stomach, it can make your blood glucose level too low. Alcohol also can raise your blood fats. If you want to drink alcohol, talk with your doctor or diabetes teacher about how it fits into your meal plan.

Your Meal Plan

Print out this chart to plan your meals and snacks for one day. (Work with your diabetes teacher if you need help.)

Measuring Your Food

To make sure your food servings are the right size, use

• measuring cups
• measuring spoons
• a food scale

Also, the Nutrition Facts label on food packages tells you how much of that food is in one serving.

Weigh or measure foods to make sure you eat the right amounts.

These tips will help you choose the right serving sizes.

• Measure a serving size of dry cereal or hot cereal, pasta, or rice and pour it into a bowl or plate. The next time you eat that food, use the same bowl or plate and fill it to the same level.
  
• For one serving of milk, measure 1 cup and pour it into a glass. See how high it fills the glass. Always drink milk out of that size glass.
  
• Meat weighs more before it's cooked. For example, 4 ounces of raw meat will weigh about 3 ounces after cooking. For meat with a bone, like a pork chop or chicken leg, cook 5 ounces raw to get 3 ounces cooked.
  
• One serving of meat or meat substitute is about the size and thickness of the palm of your hand or a deck of cards.
  
• A small fist is equal to about 1/2 cup of fruit, vegetables, or starches like rice.
  
• A small fist is equal to 1 small piece of fresh fruit.
  
• A thumb is equal to about 1 ounce of meat or cheese.
  
• The tip of a thumb is equal to about 1 teaspoon.

When You Are Sick

It's important to take care of your diabetes even when you're ill. Here are some tips on what to do:

• Even if you can't keep food down, keep taking your diabetes medicine.
  
• Drink at least one cup (8 ounces) of water or other calorie-free, caffeine-free liquid every hour while you're awake.
  
• If you can't eat your usual food, try drinking juice or eating crackers, popsicles, or soup.
  
• If you can't eat at all, drink clear liquids such as ginger ale. Eat or drink something with sugar in it if you have trouble keeping food down, because you still need calories. If you don't have enough calories, you increase your risk of hypoglycemia (low blood sugar).
  
• Make sure that you check your blood glucose. Your blood glucose level may be high even if you're not eating.
  
• Call your doctor right away if you throw up more than once or have diarrhea for more than 6 hours.

Points to Remember

• What, when, and how much you eat all affect your blood glucose level.
  
• You can keep your blood glucose at a healthy level if you
  • Eat about the same amount of food each day.
  • Eat at about the same times each day.
  • Take your medicines at the same times each day.
  • Exercise at the same times each day.
• Every day, choose foods from these food groups: starches, vegetables, fruit, meat and meat substitutes, and milk and yogurt. How much of each depends on how many calories you need a day.
  
• Limit the amounts of fats and sweets you eat each day