A two-year follow-up Study: Validity of bioelectrical impedance analysis to detect alteration in appendicular lean mass in Arab men

The aim of current study was to determine the validity of bioelectrical impedance analysis (BIA) to detect a 2-year follow-up in body composition compared with dual-energy X-ray absorptiometry (DXA). A follow-up repeated measure design was implemented. 51 healthy men with an average age 33.8 ±12.2 years, and average Body Mass Index (BMI) of 29.1 ±5.1 kg/m2 participated in the current study. The average appendicular lean mass (ALM) divided by height squared (ALM/ht2) and pre-sarcopenia as 1 SD below the average value based on specific reference values of young Saudi men were used. The reference value for DXA was 7.74 kg/m2 and for Tanita was 8.68 kg/m2. Results showed no significant differences in body composition between baseline and follow up measures using DXA and Tanita (P > 0.05). Tanita has a sensitivity of 66.7% and specificity of 69.6% compared to DXA at baseline and had a sensitivity of 100.0% and specificity of 86.4% when compared to DXA. Bland-Altman analysis showed that the mean difference between the measure of Tanita at baseline and follow up was -0.17 with upper and lower limit for agreement 1.82 and -2.17 respectively, and the comparison for DXA at baseline and follow up showed mean difference -0.04 with upper and lower limit for agreement 2.35 and -2.43 respectively. In conclusion, a short-term 2-year follow-up measures showed no differences in body composition including ALM. Tanita MC-980 has a strong level of sensitivity and specificity in the follow up measure in comparison with DXA.