Diabetes - Type 2
Basics
Diabetes is a chronic disease in which the body makes little or no insulin, or is unable to use the insulin it makes. Insulin is a hormone produced by the pancreas that helps your body use the energy from sugar, starches, and other foods. When insulin is absent or ineffective, blood sugar (glucose) levels become higher than normal. Over time, high blood sugar levels can damage blood vessels and nerves, and lead to serious health problems such as blindness, kidney failure, heart attack, and stroke.
Type 2 diabetes, previously called adult-onset diabetes or noninsulin-dependent diabetes mellitus (NIDDM), accounts for 90% of diabetes cases. While it tends to develop gradually after the age of 40, type 2 diabetes is now being diagnosed in many overweight children and young adults, and is beginning to reach epidemic proportions.
Type 2 diabetes is associated with high levels of harmful blood fat (LDL cholesterol) and high blood pressure. The high blood glucose levels seen in type 2 diabetes cause high levels of a harmful blood fat (LDL cholesterol) and low levels of the good kind of blood fat (HDL cholesterol). This imbalance of cholesterol can lead to hardened arteries (atherosclerosis), which causes poor circulation and various other complications. Type 2 diabetes is also associated with high blood pressure.
Causes
Type 2 diabetes occurs when your body responds inefficiently to the hormone insulin, which regulates blood sugar Figure 01. Insulin is secreted by the pancreas. Normally, when insulin interacts with cells, it starts a chain reaction that ends when simple sugar (glucose) from digested carbohydrates enters cells from the bloodstream and is turned into energy or fat.
People with type 2 diabetes have cells that don't respond effectively to insulin. As a result of this inability to use insulin, glucose in the bloodstream goes unused, and can build to dangerous levels. This insulin resistance is pronounced in people with type 2 diabetes who are overweight or obese. Over time, type 2 diabetics may progress from having adequate or even greater than adequate amounts of insulin to insulin deficiency, as the insulin-producing cells in the pancreas “burn out.” This is why type 2 diabetics have blood sugar levels that become more difficult to control, and require increasing medication with time.
Insulin resistance can be inherited, or can develop as a consequence of lifestyle. Twin studies show that diabetes is an inherited disorder; however, the genetic pattern of inheritance is not yet fully understood.
Being overweight, having poor eating habits, and living a sedentary lifestyle also contribute to the risk of developing diabetes.
Figure 01. Cellular mechanisms of diabetes (animation and audio)
Symptoms
You can have type 2 diabetes without having any symptoms. However, type 2 diabetes often causes frequent urination and thirst Table 01. Type 2 diabetes may come on so gradually that you don't even notice it. In these cases, the first symptoms you may experience will reflect nerve damage in your hands or feet because of impaired circulation. You may, however, feel the need to urinate frequently, or excrete a larger amount of urine than normal. These symptoms occur because your kidneys excrete extra water to dilute the sugar that has entered your urine. As your body excretes extra water, you will become dehydrated and thirsty.
Later symptoms include weight loss despite increased hunger and food intake. This occurs because diabetics are unable to use their blood glucose for energy, so body fat is burned in an attempt to provide “fuel”. Other symptoms may include blurred vision, weakness and fatigue, recurring vaginal yeast infections, and skin infections.
Table 1. Common Symptoms of Type 2 Diabetes
| Increased thirst |
| Frequent urination |
| Weight loss |
| Fatigue |
| Numbness or tingling in the hands or feet |
| Problems with sexual function |
| Blurred vision |
| Yeast infections, or other vaginal or urinary tract infections |
| Skin infections or slow-healing cuts or sores |
Risk Factors
Heredity and ethnicity can be risk factors for type 2 diabetes Table 02. Type 2 diabetes sometimes runs in families. Having a mother with the disease seems to be a particularly strong factor: research indicates that patients whose mothers have diabetes are twice as likely to get the disease as those whose father has it. Ethnic background influences risk as well. African Americans, Hispanics, and Native Americans account for a disproportionate number of type 2 diabetes cases. In fact, the Pima Indians of Arizona have the highest incidence in the world: 10 times that of the general U.S. population.
Your risk for diabetes increases with age. The risk of developing type 2 diabetes increases after the age of 45, with significant increased risk in persons 65 years of age or older. However, as mentioned previously, type 2 diabetes is being diagnosed in more and more children and young adults who are obese and sedentary.
Being overweight or obese increases your risk for type 2 diabetes. The vast majority of people with type 2 diabetes are obese.
The combination of obesity, hypertension, and high cholesterol, known as the metabolic syndrome, is a risk factor for diabetes. This condition also puts people at risk for heart disease and strokes Hardening of the arteries (atherosclerosis), caused by accumulated cholesterol and other blood fats and cellular debris, is twice as common in people with diabetes. Therefore, diabetics have a higher risk for heart attacks and strokes than non-diabetics. This increase in cardiovascular risk in type 2 diabetics is associated with the combination of insulin resistance due to obesity, problems with lipid (fat) metabolism, and hypertension.
Having diabetes during pregnancy, having delivered a large baby (more than 9 pounds), or having impaired glucose tolerance increases your chances of developing Type 2 diabetes.
Table 2. Risk Factors for Type 2 Diabetes
| Obesity (weighing 20% or more over desired body weight) |
| Impaired glucose tolerance |
| Having a parent or sibling with diabetes |
| African-American, Hispanic, Asian-Americans/Pacific Islander, or Native-American ethnicity |
| Age of 45 years or older |
| Having delivered a baby weighing more than 9 pounds |
| History of diabetes during pregnancy |
| Blood pressure of 140/90 mmHg or higher |
| HDL cholesterol of 35 mg/dL or lower and/or triglyceride level of 250 or higher |
Diagnosis
Diabetes is a chronic disease in which the body makes little or no insulin, or is unable to use the insulin it makes. Insulin is a hormone produced by the pancreas that helps your body use the energy from sugar, starches, and other foods. When insulin is absent or ineffective, blood sugar (glucose) levels become higher than normal. Over time, high blood sugar levels can damage blood vessels and nerves, and lead to serious health problems such as blindness, kidney failure, heart attack, and stroke.
Type 2 diabetes, previously called adult-onset diabetes or noninsulin-dependent diabetes mellitus (NIDDM), accounts for 90% of diabetes cases. While it tends to develop gradually after the age of 40, type 2 diabetes is now being diagnosed in many overweight children and young adults, and is beginning to reach epidemic proportions.
Type 2 diabetes is associated with high levels of harmful blood fat (LDL cholesterol) and high blood pressure. The high blood glucose levels seen in type 2 diabetes cause high levels of a harmful blood fat (LDL cholesterol) and low levels of the good kind of blood fat (HDL cholesterol). This imbalance of cholesterol can lead to hardened arteries (atherosclerosis), which causes poor circulation and various other complications. Type 2 diabetes is also associated with high blood pressure.
Type 2 diabetes occurs when your body responds inefficiently to the hormone insulin, which regulates blood sugar Figure 01. Insulin is secreted by the pancreas. Normally, when insulin interacts with cells, it starts a chain reaction that ends when simple sugar (glucose) from digested carbohydrates enters cells from the bloodstream and is turned into energy or fat.
People with type 2 diabetes have cells that don't respond effectively to insulin. As a result of this inability to use insulin, glucose in the bloodstream goes unused, and can build to dangerous levels. This insulin resistance is pronounced in people with type 2 diabetes who are overweight or obese. Over time, type 2 diabetics may progress from having adequate or even greater than adequate amounts of insulin to insulin deficiency, as the insulin-producing cells in the pancreas “burn out.” This is why type 2 diabetics have blood sugar levels that become more difficult to control, and require increasing medication with time.
Insulin resistance can be inherited, or can develop as a consequence of lifestyle. Twin studies show that diabetes is an inherited disorder; however, the genetic pattern of inheritance is not yet fully understood.
Being overweight, having poor eating habits, and living a sedentary lifestyle also contribute to the risk of developing diabetes.Figure 01. Cellular mechanisms of diabetes (animation and audio)
You can have type 2 diabetes without having any symptoms. However, type 2 diabetes often causes frequent urination and thirst Table 01. Type 2 diabetes may come on so gradually that you don't even notice it. In these cases, the first symptoms you may experience will reflect nerve damage in your hands or feet because of impaired circulation. You may, however, feel the need to urinate frequently, or excrete a larger amount of urine than normal. These symptoms occur because your kidneys excrete extra water to dilute the sugar that has entered your urine. As your body excretes extra water, you will become dehydrated and thirsty.
Later symptoms include weight loss despite increased hunger and food intake. This occurs because diabetics are unable to use their blood glucose for energy, so body fat is burned in an attempt to provide “fuel”. Other symptoms may include blurred vision, weakness and fatigue, recurring vaginal yeast infections, and skin infections.
Table 1. Common Symptoms of Type 2 Diabetes
| Increased thirst |
| Frequent urination |
| Weight loss |
| Fatigue |
| Numbness or tingling in the hands or feet |
| Problems with sexual function |
| Blurred vision |
| Yeast infections, or other vaginal or urinary tract infections |
| Skin infections or slow-healing cuts or sores |
Heredity and ethnicity can be risk factors for type 2 diabetes Table 02. Type 2 diabetes sometimes runs in families. Having a mother with the disease seems to be a particularly strong factor: research indicates that patients whose mothers have diabetes are twice as likely to get the disease as those whose father has it. Ethnic background influences risk as well. African Americans, Hispanics, and Native Americans account for a disproportionate number of type 2 diabetes cases. In fact, the Pima Indians of Arizona have the highest incidence in the world: 10 times that of the general U.S. population.
Your risk for diabetes increases with age. The risk of developing type 2 diabetes increases after the age of 45, with significant increased risk in persons 65 years of age or older. However, as mentioned previously, type 2 diabetes is being diagnosed in more and more children and young adults who are obese and sedentary.
Being overweight or obese increases your risk for type 2 diabetes. The vast majority of people with type 2 diabetes are obese.
The combination of obesity, hypertension, and high cholesterol, known as the metabolic syndrome, is a risk factor for diabetes. This condition also puts people at risk for heart disease and strokes Hardening of the arteries (atherosclerosis), caused by accumulated cholesterol and other blood fats and cellular debris, is twice as common in people with diabetes. Therefore, diabetics have a higher risk for heart attacks and strokes than non-diabetics. This increase in cardiovascular risk in type 2 diabetics is associated with the combination of insulin resistance due to obesity, problems with lipid (fat) metabolism, and hypertension.
Having diabetes during pregnancy, having delivered a large baby (more than 9 pounds), or having impaired glucose tolerance increases your chances of developing Type 2 diabetes.
Table 2. Risk Factors for Type 2 Diabetes
| Obesity (weighing 20% or more over desired body weight) |
| Impaired glucose tolerance |
| Having a parent or sibling with diabetes |
| African-American, Hispanic, Asian-Americans/Pacific Islander, or Native-American ethnicity |
| Age of 45 years or older |
| Having delivered a baby weighing more than 9 pounds |
| History of diabetes during pregnancy |
| Blood pressure of 140/90 mmHg or higher |
| HDL cholesterol of 35 mg/dL or lower and/or triglyceride level of 250 or higher |
To diagnose diabetes, your doctor will take your medical history and conduct a physical examination. Your doctor will check your height, weight, and blood pressure, and will look for evidence of nerve damage. Your doctor will also do an eye exam to look for a complication that results when blood vessels supplying the retina are damaged (retinopathy). The doctor will also examine your mouth, heart, skin, and feet (people with diabetes sometimes lose sensation in their feet, and may not notice sores that have been caused by trauma).
Your doctor will run blood tests to confirm a diagnosis of diabetes. Your blood sugar level will help determine whether or not you have diabetes.
Your doctor may also do a blood test called the hemoglobin A1C test (also referred to as glycohemoglobin or glycosylated hemoglobin test). This is a measure of blood sugar control over time (the preceding three months), and is the standard for predicting the risk of developing long-term complications. According to the American Diabetes Association, a hemoglobin A1C level of
You should be screened for type 2 diabetes every three years starting at age 45. If you are younger than 45 but have risk factors for diabetes, you should be screened more frequently.
Get regular exercise. Research is showing that exercise appears to lower your chance of getting diabetes. In one study, middle-aged men who did at least 40 minutes of brisk walking daily, slow swimming, bicycling, or other moderate-intensity physical activity had half the risk for developing Type 2 diabetes than did men who exercised less. If you have a family history of diabetes, the benefits of exercise for preventing diabetes are even greater. Regular exercise also helps to control weight and blood lipid (fat) levels.
Pay close attention to your diet, and lose weight if you are overweight Figure 02. Leading a sedentary lifestyle and eating a nutrient-poor diet high in sugar, calories, and fat contributes to obesity, which is a major risk factor for diabetes. Getting exercise and eating a balanced diet can help you lose weight and prevent diabetes.
Figure 02. Body mass index (BMI)
Prevention and Screening
You should be screened for type 2 diabetes every three years starting at age 45. If you are younger than 45 but have risk factors for diabetes, you should be screened more frequently.
Get regular exercise. Research is showing that exercise appears to lower your chance of getting diabetes. In one study, middle-aged men who did at least 40 minutes of brisk walking daily, slow swimming, bicycling, or other moderate-intensity physical activity had half the risk for developing Type 2 diabetes than did men who exercised less. If you have a family history of diabetes, the benefits of exercise for preventing diabetes are even greater. Regular exercise also helps to control weight and blood lipid (fat) levels.
Pay close attention to your diet, and lose weight if you are overweight Figure 02. Leading a sedentary lifestyle and eating a nutrient-poor diet high in sugar, calories, and fat contributes to obesity, which is a major risk factor for diabetes. Getting exercise and eating a balanced diet can help you lose weight and prevent diabetes.Figure 02. Body mass index (BMI)
Treatment
Contact your doctor immediately if you experience symptoms of low blood sugar (hypoglycemia) Table 03. Some diabetes medications, such as insulin, the sulfonylureas, and the meglitinides may cause excessively low blood sugar (hypoglycemia). Likewise, skipping meals and intense workouts can cause blood sugar levels to drop to dangerous levels. Symptoms of hypoglycemia include trembling, hunger, sweating, dizziness, and confusion. If measures are not taken to counteract hypoglycemia, seizures, coma, and even death can result.
Certain foods and drinks can boost glucose quickly. Pure forms of sugar, such as juice or hard candies, are best. Avoid foods that contain fat, as they will not be digested as rapidly. Specific recommendations for treating hypoglycemia should be discussed with your doctor. It is advised that diabetics, especially the elderly and those diabetics on insulin who are at high risk for hypoglycemia, wear medical identification.
Table 3. Warning Signs of Hypoglycemia
| Sweating |
| Heart palpitations |
| Hunger |
| Faintness |
| Weakness |
| Confusion |
| Headache |
| Numbness or tingling of the mouth and lips |
Lose weight if you are overweight. Leading a sedentary lifestyle and eating a nutrient-poor diet high in sugar, calories, and fat contributes to obesity, which is a major risk factor for diabetes. Getting exercise and eating a balanced diet can help you lose weight and prevent diabetes.
Follow a careful diet. Diet should be geared towards achieving goals for blood sugar control, cholesterol/lipid levels, and blood pressure, as well a maintaining a reasonable weight and adequate nutrition.
Follow a diet in which 50% to 60% of your daily calories come from carbohydrates, and no more than 30% of your calories come from fat. Because diabetics sometimes have high cholesterol as well, limit your intake of saturated fats, which are found in animal products like butter and red meat. Eat at regular intervals to help maintain safe blood sugar levels and prevent hypoglycemia. If you are overweight, you need to cut down on portions and restrict total calories. Consistent calorie restriction of 300-500 calories daily will result in gradual weight loss. No matter what your starting weight is, a moderate weight loss of 10-20 pounds has been shown to lower blood sugar, cholesterol levels, and blood pressure. If you have high blood pressure, you should limit your salt intake.
Maintain an exercise regimen. Exercise is an important part of diabetes treatment because it lowers blood sugar. During exercise, your body uses glucose circulating in the blood before it taps into its starch (glycogen) stores. When the starch stores are depleted, the body turns to fat cells for glucose. Lowering your body fat may be another way exercise helps improve insulin sensitivity. Exercise is also an important part of any weight loss program.
A minimum of 30 minutes of moderate-intensity activity (walking, jogging, cycling or other aerobic activity) three to four times a week, supplemented by an increase in daily lifestyle activities (such as walking breaks at work, using the stairs instead of the elevator, doing housework, or gardening) is recommended. You should check with your doctor before starting any exercise program.
Check your feet for sores and avoid foot infections. Like other parts of the body, the feet undergo wear and tear (blisters, cuts, etc.). If you have diabetes, you are prone to poor circulation and nerve damage. Because of this nerve damage and corresponding loss of sensation, you may not notice foot pain. Repeated trauma can cause the skin on your foot to breakdown. Furthermore, poor circulation will hinder healing, and unnoticed sores can become infected and ulcerated. If left untreated, the tissue on your foot will die and have to be removed.
You can avoid this complication by checking your feet daily. Be sure to tend to even the most minor cut by cleansing it thoroughly with soap and warm water and disinfecting it with a mild antiseptic. Afterwards, cover the sore with a dry sterile bandage. If you discover ulcers or have a cut or sore on your foot that is not healing or looks infected, tell your doctor right away. Trim your toenails regularly and have your doctor examine your feet at every visit (at least twice a year). Your doctor can refer you to a podiatrist to help you with regular foot care.
Get your eyes checked yearly. Poor circulation, which is characteristic of diabetes, can damage your retinas and lead to blurry vision or a complication that can lead to blindness (retinopathy). Get your eyes checked by an ophthalmologist at least yearly to help detect these complications before they become debilitating.
If you smoke, quit. Cigarette smoking is a major risk factor for cardiovascular disease.
Drink alcohol only in moderation. Alcohol contains excess calories and contributes to weight gain. If you drink on an empty stomach and take medication for your diabetes, you are at increased risk for hypoglycemia. Alcohol is broken down by your liver, and this extra stress on your liver may interfere with the functioning and clearance of medications you take for controlling diabetes and cholesterol.
Get an annual flu vaccine and get the pneumonia vaccine once before age 65. The pneumonia vaccine should be repeated after age 65 once.
Monitoring your blood sugar is an essential part of diabetes self-care. Monitoring your blood sugar will help to detect changes in the blood glucose levels caused by diet, activity, stress, illnesses, and medications. Tracking your blood glucose over time will help you achieve better blood glucose control.
Your doctor will tell you how often and when you need to monitor your blood sugar, which can be done at home with relative ease. You will have to prick your finger using a special device to obtain a small drop of blood. The drop can be placed on a reagent strip, which will change color. Judging from the changes, you can determine your blood sugar level, or you can place the strip into a blood glucose meter that provides a readout. There is a variety of meters available that range in price, features (including memory, the ability to download results to your computer, and voice applications for the visually impaired), and ease of use. It is important to consider what your health insurance covers in the way of meters and supplies (especially test strips), as these can be expensive. Your doctor or diabetes educator can help you decide which meter is best for you.
Your doctor is the best source of information on the drug treatment choices available to you.
Some people use unproven alternative remedies and nutritional supplements to lower glucose levels. Some naturalists suggest taking the mineral chromium to lower blood sugar and cholesterol levels. Others say the Indian herb Gymnema sylvestre can help improve glucose control and reduce the need for medications. However, there is little evidence that these measures are as effective as insulin or hypoglycemic agents in controlling blood sugar and preventing complications. Talk with your doctor if you wish to try these alternatives.
Although type 2 diabetes is a serious condition that can have long-term complications, controlling your blood glucose can reduce or delay the development of long-term complications.