Glycemic control
From Wikipedia, the free encyclopedia
Glycemic control is a medical term referring to the typical levels of blood sugar (glucose) in a person with diabetes mellitus. Much evidence suggests that many of the long-term complications of diabetes, especially the microvascular complications, result from many years of hyperglycemia (elevated levels of glucose in the blood). Good glycemic control, in the sense of a "target" for treatment, has become an important goal of diabetes care.
Because blood sugar levels fluctuate throughout the day and glucose records are imperfect indicators of these changes, the percentage of hemoglobin which is glycosylated is used as a proxy measure of long-term glycemic control in research trials and clinical care of people with diabetes. This test, the hemoglobin A1c or glycosylated hemoglobin reflects average glucoses over the preceding 2-3 months. In nondiabetic persons with normal glucose metabolism the glycosylated hemoglobin is usually 4-6% by the most common methods (normal ranges may vary by method).
"Perfect glycemic control" would mean that glucose levels were always normal (70-130 mg/dl, or 3.9-7.2 mMol/L) and indistinguishable from a person without diabetes. In reality, because of the imperfections of our treatment measures for replacing a pancreas, even "good glycemic control" describes blood glucose levels that average somewhat higher than normal much of the time.
Accepted "target levels" of glucose and glycosylated hemoglobin that are considered good control have been lowered over the last 25 years, because of improvements in the tools of diabetes care, because of increasing evidence of the value of glycemic control in avoiding complications, and by the expectations of both patients and physicians. What is considered "good control" also varies by age and susceptibility of the patient to hypoglycemia.
In the 1990s the American Diabetes Association conducted a publicity campaign to persuade patients and physicians to strive for average glucose and hemoglobin A1c values below 200 mg/dl and 8%. Currently many patients and physicians attempt to do better than that.
Poor glycemic control refers to persistently elevated blood glucose and glycosylated hemoglobin levels, which may range from 200-500 mg/dl (11-28 mMoles/L) and 9-15% or higher over months and years before severe complications occur.
