Objective: Although a variety of indices have been used to assess obesity, which is closely associated with the development of metabolic syndrome (MetS), the best indicator of the effects of fat accumulation on Chinese postmenopausal women is still uncertain. Thus, the objectives of this study were to analyze the potential of different obesity indices and to explore which index is best for predicting MetS in Chinese postmenopausal women.
Methods: A cross-sectional analysis of the baseline data of 1,234 Chinese postmenopausal women (aged 42-79 y) who participated in the annual health checkup was performed. The obesity indices of all participants, including body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), percent body fat (PBF), and fat mass index (FMI), were measured or calculated. The updated National Cholesterol Education Program/Adult Treatment Panel III criteria were used to assess MetS risk factors. Spearman and partial correlations were used to assess correlations between obesity indices and MetS components. The area under the curve of the receiver operating characteristic (ROC) curve was used to determine the optimal cutoff values of all indicators of MetS development. The values of BMI, WC, WHR, WHtR, PBF, and FMI that resulted in the maximization of the Youden index (sensitivity + specificity - 1) were defined as optimal.
Results: Among the participants, 38.8% (n = 479) were identified as having two or more nonadipose MetS risk components (excluding a positive WC component). These women had higher obesity indices than women with fewer metabolic risk factors. All indices were significantly associated with all MetS components even after controlling for age and C-reactive protein. A BMI of 24.0 kg/m, a WHR of 0.85, a WC of 79.9 cm, a WHtR of 0.49, a PBF of 29.9%, and an FMI of 7.2 kg/m were the optimal cutoff values for predicting at least two other MetS components according to ROC curve analysis. However, among the indicators of central obesity, WHR and WHtR showed the greatest area under the ROC curve.
Conclusions: WHR and WHtR are the best indicators of MetS development. A WHR of 0.85 or higher and a WHtR of 0.49 or higher should be incorporated into the identification of MetS risk in Chinese postmenopausal women.