By Dr. Ruchi Kaushik
The Children’s Hospital of San Antonio
Diabetes mellitus is a chronic disease caused by a lack of insulin. Insulin is a hormone produced by the pancreas, is essential to life, and helps in the metabolism of glucose, a simple sugar derived from the carbohydrates (“carbs”) in our diet. It lowers blood glucose (glucose = sugar) levels by helping glucose enter our muscle cells so we can then use it for energy. One analogy describes insulin as the “key” to opening the door to muscle cells for glucose to come in. An absence or deficiency of insulin leads to high blood sugar levels; conversely, an excess of insulin results in hypoglycemia, or low blood sugar levels. Importantly, in diabetes, even though blood sugar levels are high, the glucose cannot enter muscle cells and cannot be used for energy because the “key,” insulin, is missing. This is dangerous because glucose is the only energy source for red blood cells and the brain.
Diabetes mellitus is of two types, type 1 and type 2. In type 1 diabetes, the cells of the pancreas are either absent or destroyed. These individuals have a lifetime dependence on injectable insulin. Type 2 diabetes is more complicated. The body’s cells have become resistant to insulin. Essentially, the cells have changed their “locks.” Traditionally, type 2 diabetes has been a disease of adults; however, with increased rates of childhood obesity, as many as one-third of all new cases of diabetes in adolescents is of type 2.