Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) is a progressive metabolic disorder characterized by insulin resistance, insulin deficiency, and hyperglycemia. Nearly 21 million Americans have diabetes, and at least 54 million people over age 20 reported to have prediabetes. About 151,000 people below the age of 20 have been diagnosed with diabetes. The World Health Organization (WHO) estimates that more than 180 million people worldwide have diabetes and this number will double by 2030. In 2005, it was reported that an estimated 1.1 million people died from diabetes and 80 percent of diabetes deaths occur in low- and middle-income countries. Most of the deaths occur in people under the age of 70; 55 percent of diabetes deaths are in women.

The metabolic changes in T2DM may lead to organ damage, impairment of organ functions, and mortality due to cardiovascular disease. T2DM is often associated with obesity, hypertension, hypercholesterolemia, hypertriglyceridemia, proinflammatory cytokines, and coagulation factors, and cluster of all these risk factors may lead to cardiometabolic [Page 761]syndrome. The common symptoms of T2DM are increased thirst, increased hunger, fatigue, increased urination especially at night, weight loss, blurred vision, and sores that do not heal.

Diagnosis of T2DM

The diagnosis criteria of T2DM is based on fasting blood glucose, postprandial blood glucose, and glycosylated hemoglobin (HbA1c). The normal fasting plasma glucose levels is considered normal if it is less than 100 milligrams per deciliter (mg/dl). If the fasting plasma glucose levels of more than 126 mg/dl on two or more tests on different days indicate diabetes of an individual. 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). 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. 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.

A person has diabetes when two diagnostic tests done on different days show that the blood glucose level is high. 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. Glycosylated hemoglobin test (HbA1c) measures blood sugar control over an extended period in people with diabetes.

In general, the higher the HbA1c value, the higher the risk that develop complications such as eye disease, kidney disease, nerve damage, heart disease, and stroke. The American Diabetes Association (ADA) currently recommends an A1c goal of less than 7.0 percent. The HbA1c is linearly related to the average blood sugar over the past 1 to 3 months.

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