Influence of the Self-reported Skin Color on the Prevalence of Metabolic Syndrome in an Urban Brazilian Population

Background: The metabolic syndrome (MS) has a high prevalence in different parts of the world, with variations between different ethnic groups. Objective: This study aims at exploring the influence of the self-reported skin color on the prevalence of MS Methods: Cross-sectional study, carried out in a population subgroup (n=7,439 adults) in Salvador, Brazil. The self-reported skin color (white, mulatto or black) was used as well as the MS criterion of ATP-III. The Chi-square test for tendency was used to analyze the prevalence gradient between the groups and logistic regression, for association analysis. Results: The general prevalence of MS, adjusted for potentially confounder variables, did not differ among whites (23.3%), mulattos (23.3%) and blacks (23.4%). The analysis by sex showed, among men, a reduction in the MS prevalence of whites (26.2%, 95%Cl: 20.7-31.7), in comparison to blacks (17.5%, 95%Cl: 12.3-22.8) and an intermediate prevalence among mulattos, 21.9%, 95%Cl: 18.6-25.1, p tend. = 0.002. Among the women, the tendency was the opposite, being higher among the blacks, 27.0%, 95%Cl: 22.2-31.8, and lower among the whites, 20.5%, 95%Cl: 15.6-25.4, p tend. = 0.02. The multivariate analysis of the association between skin color and MS (white = group of reference) showed that the black color of the skin was a protective factor among black men, with a prevalence ratio (PR) = 0.60 (0.36-0.97), whereas it tended to be a risk factor among black women, with a PR = 1.33 (0.94-1.78). Conclusion: The prevalence of MA presented an inverse variation according to the color of skin between men and women. To be black was a protective factor among men and a risk factor among women. (Arq Bras Cardiol 2010; 94(1) : 33-39)