Community-Based Measurement of Body Composition in Hispanic Women: Concurrent Validity of Dual- and Single-Frequency Bioelectrical Impedance

Szeszulski, J, Lorenzo, E, Arriola, A, and Lee, RE. Community-based measurement of body composition in hispanic women: concurrent validity of dual- and single-frequency bioelectrical impedance. J Strength Cond Res XX(X): 000-000, 2019-We examined the concurrent validity of single-frequency (SF) and dual-frequency (DF) bioelectrical impedance (BIA) scales among Hispanic women participating in a community-based health promotion program in Arizona. Hispanic women (N = 14), age 31.9 +/- 6.5 years old, with a mean body mass index (BMI) of 31.1 +/- 8.1 kg.m, were measured using SF BIA, DF BIA, BMI, and skinfold calipers in 2017. Intrarater reliability and concurrent validity were calculated. Bland-Altman plots examined agreement of each BIA measure within measurement tools, between tools, and with skinfold calipers. Scatter plots were used to examine agreement between BIAs and BMI. Short-term intrarater reliability was perfect within measurements for SF and DF BIAs (alpha = 1.0). The coefficient of variation within a measurement tool (CV%) was slightly smaller for DF BIA (0.2%; n = 13) than for SF BIA (0.3%; n = 14). Concurrent validity measures revealed that DF (M = 39.3 +/- 7.3% fat; within sample CV% = 18.6; n = 14) and SF (M = 39.4 +/- 7.5% body fat; within sample CV% = 19.0; n = 14) BIAs were highly correlated (Pearson r = 0.885; p < 0.001; n = 14) and had an absolute mean difference of -0.2 +/- 3.5% fat (range 0.7-6.0% fat; n = 14). The CV% between BIA measures was 5.4%. Dual-frequency and SF BIAs were both strongly correlated with BMI and skinfolds. There was evidence of bias between skinfolds and both BIA measures. Strength and conditioning practitioners should feel confident in using either SF or DF BIA measures with Hispanic women who participate in training interventions in community-based settings, because they offer similar measurement value.