Physical Fitness and Metabolic Syndrome in Brazilian Adolescents: Validity of Diagnostic Health Criteria

Abstract

We tested health criteria cutoff points from physical fitness variables proposed by the Fitnessgram program for detecting metabolic syndrome (MetS) in a representative sample of 1,035 Brazilian adolescents (565 girls and 470 boys) aged 12-20 years. We studied five fitness tests: (a) back-saver sit and reach, (b) trunk lift, (c) curl-up, (d) push-up, and (e) progressive aerobic cardiovascular endurance run (PACER), and we defined MetS through the criteria of the International Diabetes Federation. We described the predictive performance of each fitness test in terms of sensitivity, specificity, and area under the curve (AUC) estimates of the receiver operating characteristic method. The AUCs for four tests (back-saver sit and reach, trunk lift, curl-up, and push-up) revealed low accuracy for identifying MetS in both sexes (0.50 ≥ AUC ≤ 0.60), but AUCs for the PACER test demonstrated good accuracy values between 0.72 (0.68–0.76) and 0.83 (0.78–0.89). Thus, cutoff points proposed in the Fitnessgram program for the PACER test offer an effective means of screening adolescents at higher cardiometabolic risk, which, for the age-group used in this study, should be from 40.3-44.3 ml/kg/min for boys and 38.6-40.1 ml/kg/min for girls.