Prior to a meal, the blood normally contains 80 to 110 milligrams of glucose per 100 milliliters; after eating, 100 to 140 mg/ml. Because persons with diabetes cannot utilize sugar efficiently, it builds up in the circulation. Two generally accepted definitions of diabetes (and of hyperglycemia, which means “high blood sugar”) are:
- 200 mg/ml or higher or
- 126 mg/ml or higher after fasting for eight hours
There are two types of diabetes, type 1 and type 2, which were once thought to affect distinctly different populations. Until the 1970s, type 1 was thought to be exclusive to children and adolescents and thus, it was called “juvenile diabetes”; type 2 was referred to as “adult-onset diabetes” because it rarely developed before middle age. Of the sixteen million Americans of all ages now with diabetes, type 2 accounts for nine in ten cases.
Most people with type 2 diabetes still make the hormone—but not in sufficient amounts. In type 1, however, the body’s immune system mistakes the beta cells for foreign invaders and destroys them. Accordingly, type 1 is also referred to as immune-mediated diabetes. The rise in obesity in the population of all ages has led to an increase in type 2 diabetes, including adolescents, over the past decade.