Diabetes Defined : Causes

by National Institute on Aging

(Page 2 of 8)

Diabetes is a serious, life-long disease. It cannot be cured, but careful control of blood sugar can prevent or delay the complications of this disease. A great deal of research is underway to find out exactly what causes diabetes and how to prevent it.

Causes

Diabetes is a disease that prevents the body from properly converting foods into the energy needed for daily activity. Understanding how diabetes develops starts with knowing what happens when the body digests food.

When you eat, your body changes most of the food into a form of sugar called glucose. Glucose travels through the blood stream to "fuel," or feed your cells. It is the main source of fuel for your body.

Digestive tract. For glucose to get into cells, insulin must be present. Insulin is a hormone made by the pancreas, a large organ behind the stomach.

If your body does not make enough insulin or if the insulin doesn't work the way it should, glucose can't get into your cells. It remains in your blood, while the cells are starved of energy. The level of glucose in your blood then gets too high, causing diabetes.

Over the years, high levels of glucose in the blood damage nerves and blood vessels. This can lead to complications such as heart disease and stroke, kidney disease, blindness, nerve damage, gum infections, and lower limb amputation.

There are three main forms of diabetes: type 1, type 2 and gestational diabetes. Type 1 diabetes is an autoimmune disease. An autoimmune disease occurs when the body's system for fighting infection - the immune system - turns against a part of the body.

In type 1 diabetes, the immune system attacks the insulin-producing cells in the pancreas and destroys them. The pancreas then produces little or no insulin.

At present, scientists do not know exactly what causes the body's immune system to attack the cells, but they believe that both genetic factors and environmental factors, such as viruses, are involved. Studies have begun to try to identify these factors and prevent type 1 diabetes in people at risk.

Type 2 diabetes - the most common form - is linked to obesity, high blood pressure, and high levels of bad cholesterol called triglycerides, and low levels of good cholesterol called high density lipoprotein or HDL. About 80 percent of people with type 2 diabetes are overweight. Being overweight can keep your body from using insulin properly.

When type 2 diabetes is diagnosed, the pancreas is usually producing some insulin, but not as much as needed. After several years, insulin production tends to decrease in people with type 2 diabetes.

Native Americans and Diabetes

Being over 45 years of age and overweight or obese raises the risk of developing type 2 diabetes. Other risk factors include:

• having a first-degree relative - a parent, brother, or sister - with diabetes
• being African American, American Indian or Alaska Native, Asian American or Pacific Islander, or Hispanic American/Latino.

Risk factors include:

• having gestational diabetes, or giving birth to at least one baby weighing more than 9 pounds
• having blood pressure of 140/90 or higher, or having been told that you have high blood pressure.

Risk factors include:

• having abnormal cholesterol levels - an HDL cholesterol level of 35 or lower, or a triglyceride level of 250 or higher
• being inactive or exercising fewer than three times a week.

Before people develop type 2 diabetes, they usually have pre-diabetes - a condition in which blood glucose levels are higher than normal, but not yet high enough for a diagnosis of diabetes.

People with pre-diabetes are more likely to develop diabetes within 10 years and also are more likely to have a heart attack or stroke. Pre-diabetes is common in America, according to new estimates. About 41 million people, or 40 percent of U.S. adults ages 40 to 74, have pre-diabetes.

Some women develop gestational diabetes during the late stages of pregnancy. Although this form of diabetes usually goes away after the baby is born, a woman who has had it is more likely to develop type 2 diabetes later in life. Gestational diabetes is caused by the hormones of pregnancy or a shortage of insulin.

Quiz

1. Being overweight can keep your body from making and using insulin properly.

TRUE is the correct answer. Type 2 diabetes - the most common form - is linked to obesity, high blood pressure, and high levels of bad cholesterol. About 80 percent of people with type 2 diabetes are overweight. Being overweight can keep your body from using insulin properly.

2. Scientists believe that genetic and environmental factors play a role in causing type 1 diabetes.

TRUE is the correct answer. In type 1 diabetes, the immune system attacks the cells in the pancreas that make insulin and destroys them. The pancreas then produces little or no insulin. At present, scientists do not know exactly what causes the body's system to attack the cells, but they believe that both genetic factors and environmental factors, possibly viruses, are involved.

3. If you have a cousin or an aunt with type 2 diabetes, you also are likely to develop type 2 diabetes.

FALSE is the correct answer. Having a first-degree relative - a parent, brother, or sister - with diabetes increases your risk of developing type 2 diabetes later in life. Other key risk factors include being 45 years of age or older and being overweight or obese, being part of a minority group, having gestational diabetes, having high blood pressure, having abnormal cholesterol levels, and/or being inactive or exercising fewer than three times a week.

4. Current estimates indicate that nearly 75% of U.S. adults are at risk for developing type 2 diabetes.

FALSE is the correct answer. Pre-diabetes, a condition in which blood glucose levels are higher than normal but not yet high enough for a diagnosis of diabetes, is common in America. According to new estimates, about 40 percent of U.S. adults ages 40 to 74 have pre-diabetes. Before people develop type 2 diabetes, they usually have pre-diabetes. They are more likely to develop diabetes within ten years and are also more likely to have a heart attack or stroke.

About the Author

www.nia.nih.gov
NIA, one of the 27 Institutes and Centers of NIH, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. In 1974, Congress granted authority to form NIA to provide leadership in aging research, training, health information dissemination, and other programs relevant to aging and older people.