Index of central obesity is better than waist circumference in defining metabolic syndrome

The International Diabetes Federation (IDF) global definition of metabolic syndrome suggests using race- and gender-specific waist circumference (WC) cutoffs. Previously, we have hypothesized that need for gender- and race-specific cutoffs could be obviated by supplanting WC with index of central obesity (ICO). The aim of this study was to test the utility of ICO in defining metabolic syndrome.

Data were collected from National Health and Nutrition Examination Survey (NHANES) database for year 2005-2006. Subjects were analyzed for presence of metabolic syndrome using National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. The IDF definition was modified by replacing WC with ICO. Sensitivity and specificity of the IDF definition and modified definition were compared against the NCEP ATP III definition.

Using a modified IDF definition, a common cutoff of 0.53 could be obtained for both males and females. The modified IDF definition improved sensitivity from 0.85 to 0.98 and 0.98 to 0.99 among males and females, respectively. This was at the cost of compromised specificity, which reduced from 1.0 to 0.89 and 0.98 for males and females, respectively.

ICO appears better than WC in defining metabolic syndrome in terms of better sensitivity and potential to be used with single cutoff for both genders.