Is a new waist circumference and BMI needed for African Americans for the diagnosis of metabolic syndrome?

Abstract

African Americans are noted as having a low prevalence metabolic syndrome (MetS), which is partly attributed to a reported use of MetS criteria, such as waist circumference that is not appropriate for this population group. The purpose of this study was: 1) to investigate the gender specific optimal waist cut off points, which best identify individuals with metabolic abnormalities consistent with MetS, and are independent of body mass index (BMI) cutoff values; 2) to determine the gender specific cutoff values of BMI in relation to multiple metabolic risk factors; and 3) to assess the prevalence of metabolic syndrome. In this cross-sectional study, NHANES data from 1999-2006 was analyzed. 1445 participants had complete variables for metabolic syndrome criteria. The waist circumference of 95 cm for males and 98 cm for females were found as appropriate cut-off values to identify central obesity. Body mass index at which metabolic syndrome was observed was 28 kg/m² for males and 32 kg/m² for females. Using our newly estimated waist circumference thresholds, the age-adjusted prevalence of MetS was 30.9% in males and 30.3% in females. The results indicate that for the early detection of metabolic syndrome in African American adult males, a lower cutoff value of 95 cm, rather than the 102 cm currently used is needed. The metabolic syndrome abnormalities appear at higher body mass index and waist circumference among women. Based on our findings, the prevalence of metabolic syndrome is currently underestimated among African American adult males.