The metabolic syndrome is a risk indicator of microvascular and macrovascular complications in diabetes: results from Metascreen, a multicenter diabetes clinic-based survey

OBJECTIVE: We aimed at assessing the degree of association and the predictive power of the metabolic syndrome with regard to clinically detectable complications in patients with diabetes. RESEARCH DESIGN AND METHODS: Metascreen is a cross-sectional survey of metabolic syndrome and clinically detected diabetes complications performed in 8,497 patients (7,859 with type 2 diabetes and 638 with type 1 diabetes) randomly chosen in 176 diabetes outpatient clinics throughout Italy. The metabolic syndrome was defined according to either the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) or the International Diabetes Federation (IDF) diagnostic criteria. Multivariate analyses of the association(s) between either AHA/NHLBI or IDF metabolic syndrome and clinical complications were performed. Receiver-operator characteristic (ROC) curves were constructed to compare the predictive power of the two sets of diagnostic criteria of the metabolic syndrome. RESULTS: Either definition of the metabolic syndrome was an independent statistical indicator of the presence of nephropathy and neuropathy (P < 0.02-0.01) in type 1 diabetes and of all complications (P < 0.0001), including cardiovascular disease and retinopathy, in type 2 diabetes. For each complication, the ROC curves based on either AHA/NHLBI or IDF metabolic syndrome were similar to each other and to the ROC curves constructed with all continuous traits compounding the metabolic syndrome. CONCLUSIONS: The metabolic syndrome, defined according to AHA/NHLBI or IDF diagnostic criteria, is an independent clinical indicator and may be involved in the pathogenesis of both macro- and microvascular complications of diabetes.