Predictive Validity of Handgrip Strength, Vertical Jump Power, and Plank Time in the Identification of Pediatric Sarcopenia

This study examined the predictive validity of musculoskeletal fitness tests for identifying sarcopenia in youth. The sample was 529 participants age 10 to 18 years. Indices included: total lean body mass (LBM) normalized for height (LBM index, LBMI, kg/m2), appendicular LBMI (aLBMI, kg/m[superscript 2]), and LBM to fat body mass (FBM) ratio (LBM/FBM). Lean and fat tissue were measured via DXA. The cutoff value for sarcopenia was -- 2.0 standard deviations [less than or equal to] mean for age and sex. Fitness was assessed using handgrip, plank, and vertical jump tests. Variables were standardized using the lambda-mu-sigma (LMS) method. By sex, analysis included the area under the curve (AUC), sensitivity (Se), and specificity (Sp). The ROC curves for aLBMI was highly accurate (AUCs [greater than or equal to] 0.90, Se and Sp = 86-88%) for vertical jump and moderately accurate for handgrip (AUCs = 0.87-0.88, Se and Sp = 71-75%). Fitness tests can be used to identify pediatric sarcopenia.