Body composition in urban South Asian women; development of a bioelectrical impedance analysis prediction equation

Abstract

Background: Assessment of body composition plays a significant role in combating chronic disease among South Asians. Accurate assessment of body composition by bioelectrical impedance analysis (BIA) requires population-specific equations which are currently unavailable for urban South Asian women.Aim: To assess validity of direct BIA assessment and selected equations for prediction of total body water (TBW), against Deuterium (2H2O) dilution and develop and validate a population-specific TBW equation for urban South Asian women.Subjects and method: Data of 80 urban Sri Lankan women (30–45 years) were used for this analysis. Body composition was assessed by 2H2O dilution (reference) and BIA. Available BIA equations were assessed for validity. A new TBW equation was generated and validated.Results: Direct BIA measurements and other equations did not meet validation criteria in predicting TBW. TBW by the new equation (TBW = 3.443 + 0.342 × (height2/impedance) + 0.176 × weight) correlated (p < 0.001) with TBW by reference method. TBW using the new equation was not significantly different (25.30 ± 2.4 kg) from the reference (25.32 ± 2.7 kg).Conclusion: Direct use of TBW by instrument and existing equations are less suitable for this population. The new TBW equation is suitable for body composition assessment in urban South Asian women.