Predictors of the incident metabolic syndrome in healthy obese subjects: a decade of follow-up from the Tehran Lipid and Glucose Study.

BACKGROUND/OBJECTIVE: There is limited data from long-term prospective studies on the natural course of metabolic syndrome (MetS) incidence in healthy obese phenotypes. The aim of this study was to determine the incidence and predictors of the MetS in healthy obese subjects without the MetS at baseline after a decade of follow-up.

SUBJECTS/METHODS: In this prospective cohort study, 438 obese subjects free from MetS at baseline, aged ≥20 years, were selected from among the participants of the Tehran Lipid and Glucose Study and followed up for 10 years for development of MetS. Based on national data, central obesity was defined as waist circumference cutoff point of 89 cm for men and 91 cm for women.

RESULTS: Initially, subjects had a mean age of 41.1 ± 11.8 years and a body mass index of 32.7 ± 2.7 kg/m(2). At the end of follow-up, the cumulative incidence (95% confidence interval) of MetS was 44.0 (36.8-51.1)%. In the multivariable analysis, the adjusted odds ratios of hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C) and insulin resistance for the development of MetS were 3.08 (1.39-6.79), 2.84 (1.26-6.42), 6.49 (3.18-13.25) and 2.87 (1.55-5.32), respectively. The area under receiver operating characteristic curve of all the components was significantly higher than various combinations of MetS components, except for the two models including combinations of three components, that is, triglycerides (TGs), HDL-C and fasting blood sugar, as well as, TGs, HDL-C and systolic blood pressure.

CONCLUSIONS: Our findings demonstrate that MetS developed in nearly half of the individuals during the 10 years of follow-up. Predictors of MetS in healthy obese subjects may differ from the general population, and waist circumference does not have an independent role.