Metabolic Control and Prevalent Cardiovascular Disease in Non-Insulin-dependent Diabetes Mellitus (NIDDM): The NIDDM Patient Outcomes Research Team

Abstract

PURPOSE: Cardiovascular disease is a major cause of morbidity and death in non–insulin-dependent diabetes mellitus (NIDDM). While hyperglycemia is clearly related to diabetic microvascular complications, its contribution to large-vessel atherosclerosis is controversial.PATIENTS AND METHODS: We performed an analysis of the association between glycemic control and prevalent cardiovascular disease in 1,539 participants in the NIDDM Patient Outcomes Research Team study who were under usual care in a health maintenance organization. Prevalent cardiovascular disease and its risk factors were identified by self-administered questionnaire. Cardiovascular disease was defined by the presence of coronary heart disease, peripheral vascular disease, and/or cerebrovascular disease. Glycohemoglobin and lipid levels were obtained from a computerized laboratory database.RESULTS: The mean age of participants was 63 years (range 31 to 91); 51% were women. The mean duration of NIDDM was 9 years (range <1 to 50), 35% took insulin, and 48% took sulfonylureas. Mean glycohemoglobin was 10.6%. Sixty percent had hypertension, 16% currently smoked cigarettes, and the mean total high-density lipoprotein (HDL) cholesterol ratio was 5.7. Fifty-one percent had cardiovascular disease. Cardiovascular disease prevalence remained constant across increasing quartiles of glycohemoglobin for both men and women. In contrast, prevalent cardiovascular disease was associated with established cardiovascular disease risk factors including age (67 versus 59 years, P <0.0001), hypertension (66% versus 54%, P <0.0001), current cigarette smoking (17% versus 13%, P <0.005), and total/HDL cholesterol ratio (5.9 versus 5.6, P <0.05). Cardiovascular disease was also associated with duration of NIDDM (11 versus 8 years, P <0.0001). In multiple logistic regression analysis controlling for established cardiovascular disease risk factors and diabetes duration and therapy, glycohemoglobin remained unassociated with cardiovascular disease.CONCLUSIONS: Glycemic control is not associated with prevalent cardiovascular disease in this large population of individuals with NIDDM. Conventional cardiovascular disease risk factors are independently associated with cardiovascular disease and may be a more promising focus for clinical intervention to reduce atherosclerotic complications in NIDDM.