Features of the metabolic syndrome predict higher risk of diabetes and impaired glucose tolerance - A prospective study in mauritius

OBJECTIVE - To assess the independent and joint effects of the components o f the metabolic syndrome, including leptin, which is a recently proposed ad dition to this syndrome, in predicting the cumulative incidence of impaired glucose tolerance (IGT) and diabetes among individuals with normal glucose tolerance. RESEARCH DESIGN AND METHODS - This prospective study involved 2,605 residen ts of Mauritius with normal glucose tolerance who were followed for 5 years for IGT or diabetes onset in relation to total and regional adiposity (BMI , waist-to-hip ratio [WHR]), fasting and 2-h 75-g oral glucose load glucose and insulin, total and HDL cholesterol, blood pressure, serum uric acid, t riglyceride, and leptin levels. RESULTS - A multivariate logistic regression model adjusted for age, sex, e thnicity and diabetes family history showed a significantly higher linear i ncrease in risk of IGT and diabetes in association with the following varia bles only: lasting glucose (odds ratio 1.89 [95% CI 1.51-2.34]), 2-h glucos e (1.68 [1.50-1.88]), WHR (1.30 [1.10-1.52]), BMI (1.04 [1.00-1.08]), and s erum uric acid (1.37 [1.20-1.57]). However, a nonlinear increase was seen w ith serum triglyceride and plasma leptin concentrations. No risk factors re sulted in joint effects that were greater than expected from combining indi vidual effects. CONCLUSIONS - Metabolic syndrome features independently predict a higher ri sk of diabetes or IGT in normoglycemic subjects bur in combination confer n o higher-than-expected risk of these outcomes. At higher concentrations of triglycerides and leptin, risk plateaus and even declines slightly.