The classification of diabetes mellitus has undergone a few revisions over time. The newest classification system makes use of the terms type 1 and type 2 diabetes, the stage termed IGT (Impaired Glucose Tolerance), and the class termed GDM (Gestational Diabetes Mellitus). "These changes provide an easier and more reliable means of diagnosing persons at risk of complications from hyperglycemia".(1)
Type 1 diabetes is a condition that develops due to a problem with the beta cells of the pancreas which causes a deficiency of insulin in the body. Because insulin cannot be produced, the person with type 1 diabetes is unable to control blood sugar levels without daily insulin supplementation. For most this means injections of insulin under the skin but for some, a pump can deliver insulin continually throughout the day. Insulin is not available in a pill form.
Type 2 diabetes is the more common form of diabetes and results when a person develops a resistance to insulin along with a problem secreting enough insulin to control blood sugar levels. These patients do not typically need insulin treatment and can often control their condition with proper diet and exercise and by losing excess weight.
IGT stands for impaired glucose tolerance and is a stage that can lead to diabetes; it is associated with insulin resistance and an increased risk of heart and blood vascular disease. Treatment for IGT includes lifestyle changes including regular exercise and limiting sugar intake.
GDM stands for gestational diabetes mellitus and is only seen in pregnant women usually in the third trimester of the pregnancy. Signs of gestational diabetes can be easily overlooked because they are similar to signs of pregnancy. It is important for a pregnant woman to alert her doctor if she is noticing an increase in thirst, more frequent urination, a feeling of always being hungry even soon after eating or blurred vision.
Diabetes is a group of metabolic diseases; diabetes mellitus classification has been revised over the years and consists of the two major types being named type 1 and type 2.
Other diabetes mellitus classifications include gestational diabetes mellitus, and a stage leading to diabetes named impaired glucose tolerance. All classifications are linked together by the common manifestation which is high blood sugar levels.
(1) American Academy of Family Physician (1998). Diagnosis and Classification of Diabetes Mellitus: New Criteria. Retrieved from http://www.aafp.org/afp/981015ap/mayfield.html