Muscle strength cut-points for metabolic syndrome detection among adults and the elderly from Brazil

We aimed to determine cut-points for muscle strength based on metabolic syndrome diagnosis. This cross-sectional analysis comprised data from 2 cohorts in Brazil (EpiFloripa Adult, n = 626, 44.0 ± 11.1 years; EpiFloripa Aging, n = 365, 71.6 ± 6.1 years). Metabolic syndrome was assessed by relative handgrip strength (kgf/kg). Metabolic syndrome was defined as including ≥3 of the 5 metabolic abnormalities according to the Joint Interim Statement. Optimal cut-points from Receiver Operating Characteristic (ROC) curves were determined. Adjusted logistic regression was used to test the association between metabolic syndrome and the cut-points created. The cut-point identified for muscle strength was 1.07 kgf/kg (Youden index = 0.310; area under the curve (AUC)) = 0.693, 95% CI 0.614-0.764) for men and 0.73 kgf/kg (Youden index = 0.481; AUC = 0.768, 95% confidence interval (CI) = 0.709-0.821) for women (age group 25 to < 50 years). The best cut-points for men and women aged 50+ years were 0.99 kgf/kg (Youden index = 0.312; AUC = 0.651; 95% CI = 0.583-0.714) and 0.58 kgf/kg (Youden index = 0.378; AUC = 0.743; 95% CI = 0.696-0.786), respectively. Cut-points derived from ROC analysis have good discriminatory power for metabolic syndrome among adults aged 25 to <50 years but not for adults aged 50+ years. Novelty: First-line management recommendation for metabolic syndrome is lifestyle modification, including improvement of muscle strength. Cut-points for muscle strength levels according to sex and age range based on metabolic syndrome were created. Cut-points for muscle strength can assist in the identification of adults at risk for cardiometabolic disease.