Cross-validation of 20 anthropometric prediction equations for appendicular muscle mass in older Brazilian women: a cross-sectional study

Objective: To test the cross-validation of anthropometric prediction equations for appendicular muscle mass (AMM) in older Brazilian women. Methods: Sixty-seven women (69.84 ± 5.95 years old) underwent measurements. AMM (kg) reference values obtained by dual-energy X-ray absorptiometry (AMMDXA) were compared to 20 estimating adults. A paired t-test (p > 0.05), standard error estimate (SEE < 3.50 kg), and r2 0.70 confirmed validity equations. The agreement between predictions was also verified (Bland-Altman). Results: Four American one Mexican equation not statistically different from AMMDXA 0.05) but did present suitable validation. National Health Nutrition Examination Survey (NHANES), = (-0.04 × age [years]) + (0.46 calf circumference [cm]) (0.32 arm (0.11 thigh – (0.27 body index [BMI, kg/m2]) (0.07 waist 13 119) showed best performance (r2 0.64; SEE 3.24 with minimal mean difference (0.26 no heteroscedasticity extreme values, high sample (-3.90 3.40 kg). Conclusion: When specific a given population are available, use generic greater representativeness scientifically reliably analyzed data is allowed.