Diabetes is not one disease. Rather, it is a group of related syndromes. What these syndromes have in common is an elevation of blood sugar. This is caused by a relative deficiency in the hormone insulin, or a resistance to the insulin your body does produce, or both. As a result, health problems may ensue.
About Diabetes
Diabetes mellitus is the leading cause of adult blindness and a major cause of kidney failure, heart attacks and strokes. Approximately 16 million people in the United States have diabetes mellitus, of which approximately 15 million have Type 2 diabetes, which is by far the most common, according to the textbook "Current Medical Diagnosis and Treatment, 2011." The rate of Type 2 diabetes is on the rise, as more people are overweight and inactive. These lifestyle factors contribute to the metabolic changes characteristic of the disease.
Type 2 Diabetes and Insulin
In Type 2 diabetes, the pancreas is unable to produce enough insulin to adequately lower blood sugar levels. This usually occurs after years of eating high-sugar foods, which require a large output of insulin. The pancreas then suffers a "burnout," releasing insufficient amounts of the hormone. In addition, the body is unable to properly use the insulin that is available. This is called insulin resistance. When high levels of glucose remain in the blood, it can damage the blood vessels, causing plaques to form. Atherosclerosis, as this is called, is a risk factor for heart disease, stroke and other conditions associated with diabetes.
Metabolic Changes in Type 2 Diabetes
The metabolic abnormalities of type 2 diabetes mellitus result from insulin resistance, or the body's inability to use insulin efficiently. Your liver, muscle and fat cells require insulin to absorb glucose and insufficient levels can leave them starved for fuel. In insulin resistance, the liver responds by manufacturing more glucose, which can further elevate blood sugar levels. Insulin resistance also affects your body's ability to use fat. As a result, blood levels of triglycerides, another term for fat, can rise to unhealthy levels. This is known as hypertriglyceridemia.
Metabolic Syndrome
If you are overweight and/or underactive, your risk increases for developing Type 2 diabetes goes up and may first manifest as a condition known as metabolic syndrome. Metabolic syndrome is the presence of three or more risk factors for diabetes, which include a large waist size, high levels of triglycerides and cholesterol in the blood, elevated blood pressure and a fasting blood glucose of 100 mg/dL or higher, where normal blood sugar is around 70 mg/dL. Doctors use a fasting blood glucose of 126 mg/dL or greater to diagnose diabetes.
References
- National Diabetes Information Clearinghouse: Insulin Resistance and Pre-diabetes
- "Biochemistry"; Richard A. Harvey, Ph.D.; 2010
- "Current Medical Diagnosis and Treatment"; Stephen McPhee, M.D.; 2011
