Blood glucose and atherosclerosis.

T relationship of diabetes to cardiovascular disease has been known for over half a century and has been the subject of a number of reviews. The topic was discussed by the author and two colleagues in 1975, and the present paper concentrates on information published since that time. Although it is well known that diabetic patients commonly die from cardiovascular disease and that cardiovascular disease is particularly common in diabetes, a number of questions remain unanswered. It is now clear that diabetes mellitus consists of at least two distinct disorders that differ both genetically and in their metabolic abnormalities. The majority of diabetics have Type II, or noninsulin-dependent, diabetes mellitus (NIDDM), characterized by mild to moderate glucose intolerance, a high frequency of obesity, absence of a tendency to ketoacidosis, and response to treatment with diet or oral antidiabetic drugs. A minority (20%) of diabetics have Type I, or insulin-dependent, diabetes mellitus (IDDM), characterized by marked hyperglycemia, weight loss, and a requirement for insulin therapy to prevent the development of ketoacidosis. The old terms of "juvenile diabetes" for IDDM and "maturity-onset diabetes" for NIDDM are no longer used, as either type of diabetes can occur at any age. The possibility that the two major types of diabetes have different relationships to atherosclerosis remains to be explored. The criteria for the diagnosis of diabetes are clearly arbitrary, although they correlate with clinical and epidemiological data. Assessment of the severity of diabetes is even more arbitrary, while the duration of diabetes can only be measured as the time since diagnosis.