Diabetes Mellitus

The leading cause of adult blindness, kidney failure and lower limb amputations is diabetes. The etiology or cause(s) of diabetes is not fully understood, but is known to be quite complex.

Increased blood sugar levels in the body characterize the disease and there are two types of diabetes: Type 1 or Insulin dependent diabetes mellitus (IDDM) and Type 2 or Non-insulin dependent diabetes mellitus (NIDDM).

Type 1 diabetes accounts for 5-10% of diabetes cases. It is considered an autoimmune disorder in which an individual’s immune system attacks its own insulin producing cells in the pancreas. This type of diabetes usually presents before the age of 40 and the individual requires an external source of insulin.

Siblings of individuals with Type 1 have a substantially increased risk of developing diabetes: about 6% as compared to the general population risk of 0.3-0.5%. There is strong evidence that certain viral infections may contribute to developing Type 1 by exciting the individual’s immune response. Several genes may also be involved in this disease.

Type 2 diabetes is the most common form accounting for more than 90% of all diabetes cases. In Type 2, an individual usually produces some insulin, but may exhibit insulin resistance, which is difficulty in using Diabetes mellitus

Genetic the insulin that is produced. This type of diabetes is often successfully controlled through diet and/or medication. Type 2 is not an autoimmune disease and usually presents after age 40.

Siblings of Type 2 individuals have a much higher recurrence risk than those of Type 1: 10-15% as compared to 6%.

The two most important risk factors for developing Type 2 diabetes are family history and obesity. The disease increases in prevalence when individuals or populations adopt the diet and exercise patterns of the United States. Exercise substantially reduces the risk of developing Type 2.

A subset of Type 2 diabetes is a form called MODY for “Maturity onset diabetes of the young”. This form accounts for 2-5% of Type 2 cases and is generally evident before the age of 25. Strong evidence exists to suggest that genetics play a significant role in the development of MODY.

Diabetes is one of the disorders that we categorize as having multifactorial causes: a combination of genetic predisposition and environmental factors.