Obesity related to metabolic syndrome: comparison of obesity indicators in an older french population

OBJECTIVES: Metabolic syndrome (MS) represents a cluster of metabolic abnormalities. Insulin resistance is a major component of the syndrome. We analyze in this study the relationship between body fat composition and MS in comparison to usual obesity indicators in an older adult population. DESIGN: : The PROgnostic indicator OF cardiovascular and cerebrovascular events (PROOF) study is a prospective longitudinal community cohort study among the inhabitants of Saint-Etienne, France. METHODS: The study is a cohort study of 1011 subjects, mean age 65.6 ± 0.8 years old at inclusion, recruited from the electoral list of the town in 2000. Among them, 806 subjects realized a Dual-energy X-ray absorptiometry (DXA) used to evaluate body fat and lean mass repartition. We evaluate biological metabolic parameters according to usual techniques. The indices of obesity were calculated according to standard formula. MS presence and its components were simultaneously evaluated. RESULTS: All obesity parameters were significantly higher (p < 0.0001) in subjects suffering metabolic syndrome as compared to those without. Body fat index (BFI) presented a stronger correlation to total fat mass, trunk fat mass and body adiposity index (BAI). The correlations between body indices and metabolic components showed that body mass index (BMI) and waist circumference were more strongly associated with BFI as compared to BAI and total fat mass. According to logistic regression analysis, only the waist-hip ratio (WHR) demonstrated a significant association with MS severity (p < 0.0001). CONCLUSIONS: Among the obesity indices, BFI and BAI represented the best indicators to characterize global obesity while WHR only is highly predictive of metabolic syndrome presence and severity. The BAI indicator is an alternative for measuring obesity. Comparison of long-term impact of such markers on cardiovascular morbidity and mortality is now questioned.