Diabetes mellitus (DM) is a chronic disease that can affect many parts of the body, including the heart, the kidney, the eyes, and the nerves. It occurs because of too much sugar in the blood, a condition called hyperglycemia. There are two main types of diabetes mellitus, type 1 and type 2. In type 2 DM, the direct cause results from a condition called insulin resistance; however, type 2 DM can also result from both genetic and by environmental factors.
Insulin Resistance
In type 2 diabetes mellitus, hyperglycemia occurs because the body develops a condition called insulin resistance. This occurs gradually: over time, the body's muscle, fat, and liver cells become unable to respond correctly to the insulin that the pancreas produces. Without the ability to use insulin correctly, the body becomes unable to process sugar and bring it into the cells of the body. When this occurs, the sugar accumulates in the blood, resulting in hyperglycemia. In contrast with type 1 diabetes, enough insulin circulates in the body to prevent the acute life-threatening complication of diabetes (diabetic ketoacidosis), but not enough to prevent hyperglycemia. As a result, a variety of complications may occur. Some of these possible complications include visual changes, heart problems and nerve damage.
Genetics
Medical evidence suggests that Type 2 DM has a strong genetic component. At least 18 different areas on genes have an association with an increased chance of developing type 2 DM. However more research needs to be done, but it seems quite clear that the genes we inherit from our parents play an important role in the risk of developing this disease.
Overweight and Obesity
Obesity means that someone is extremely overweight, and this presents the most significant non-genetic risk factor for developing type 2 DM. This occurs because as fat accumulation in the body increases, insulin resistance increases as well. That is, the more fat a person has, the harder it becomes for the body to use insulin correctly. Interestingly, it appears that a certain type of fat, called visceral fat, has a significant link to the development of insulin resistance than fat deposited around the abdomen. Regardless of the specifics, remember that being overweight and especially being obese, greatly increases the potential for developing type 2 DM.
References
- "CURRENT Medical Diagnosis and Treatment"; Stephen McPhee et. al.; 2010
- "Greenspan's Basic & Clinical Endocrinology"; David G. Gardner and Dolores Shoback; 2007
