Determinação dos pontos de corte de parâmetros antropométricos de obesidade e obesidade central para síndrome metabólica e risco cardiovascular em idosos da atenção básica

Abstract

Introduction : Anthropometry is a simple and effective method to identify excess body fat and, therefore, individuals with higher risk for cardiovascular disease (CVD), in addition to being one of the diagnostic criteria for metabolic syndrome (MetS). During the course of aging, body composition changes occur, however, for most anthropometric measurements, no specific cut-off points have been determined for this age group, which are fundamental for prevention and management of CVD risk factors, especially in basic attention. Objective : to determine optimal cut-off points for anthropometric measurements [body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-hip ratio (WHR)] for MetS and CVD in elderly served by the family health strategy. Methods : descriptive and analytical cross-sectional study, which evaluated 518 elderly, from 30 Family Health Strategy units from Porto Alegre, participants of the Epidemiological and Clinical Study of Elderly Served by the participants of seniors served by the Family Health Strategy of Porto Alegre (EMISUS). In anthropometric assessment were obtained the BMI, WC (obtained at the midpoint between the last rib and iliac crest), WHtR and WHR. For the diagnosis of MetS, we used the revised NCEP-ATPIII. To determine the risk of cardiovascular disease, we used the Framingham risk score. The cut-off points of anthropometric measurements were obtained from the construction of the ROC curves using the software SPSS (for analyses, individuals classified as intermediate and high risk were grouped together). Results : most of the sample was composed of 326 women (62.9%). The average age was 68.25±6.7 years (60-100 years). It was possible to establish the diagnosis for MetS in 469 individuals, being classified as suffering from MetS 334 individuals (71,2%). It was possible to determine the risk of CVD on 362 individuals, of who 186 were classified as low risk (51.4%), 144 as intermediate risk (39.8%) and 32 as high risk (8.8%). Considering MetS, the cut-off points with discriminatory power relevance were BMI≥26.8kg/m² for the total sample, ≥25.2kg/m² for men and ≥27.8kg/m² for women. For WC, the values were ≥93.7cm for the general population, ≥94.8cm for men and ≥91.7cm for women. For WHtR, found values of ≥0.59 for the total population, ≥0.57 for men and ≥0.61 for women. In relation to the WHR, the values were ≥0.95 to total population, ≥0.99 for men and ≥0.93 for women. To determine the risk of CVD, the most significant values were BMI ≥27.8kg/m² for the general population, WC ≥93.7cm for men, WHtR ≥0.57 for men and WHR ≥ 0.96 for the total population. Conclusion : for discrimination of SM, the areas under the curve of anthropometric parameters were representative, both in the total sample as between the genders. As for the discrimination of CVD risk intermediate/high, areas below the curve of BMI and WHR were representative only in the total sample, and of WC and WHtR only in men.