Metabolic Syndrome as a Risk Factor for Cardiovascular Disease, Mortality, and Progression of Diabetic Nephropathy in Type 1 Diabetes

OBJECTIVE: To assess the predictive value of the metabolic syndrome in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: Patients were from the prospective Finnish Diabetic Nephropathy (FinnDiane) Study (n = 3,783): mean age 37 ± 12 years and diabetes duration 23 ± 12 years. Metabolic syndrome was defined according to World Health Organization (WHO), National Cholesterol Education Program (NCEP), and International Diabetes Federation (IDF) definitions. Follow-up time was median 5.5 years (interquartile range 3.7–6.7). Mortality data were complete, whereas morbidity data were available in 69% of the patients. RESULTS: The WHO definition was associated with a 2.1-fold increased risk of cardiovascular events and a 2.5-fold increased risk of cardiovascular- and diabetes-related mortality, after adjustment for traditional risk factors and diabetic nephropathy. The NCEP definition did not predict outcomes when adjusted for nephropathy but markedly added to the risk associated with elevated albuminuria alone (P < 0.001). The IDF definition did not predict outcomes. CONCLUSIONS: The metabolic syndrome is a risk factor, beyond albuminuria, for cardiovascular morbidity and diabetes-related mortality in type 1 diabetes.