Bioimpedance analysis of body composition in an international twin cohort.

ABSTRACT

OBJECTIVE: Multiple twin studies have demonstrated the heritability of anthropometric and metabolic traits. However, assessment of body composition parameters by bioimpedance analysis (BIA) has not been routinely performed in this setting. DESIGN: A cross-sectional study. SETTING: Study subjects were recruited and assessed at twin festivals or at major university hospitals in Italy, Hungary, and the United States to estimate the influence of genetic and environmental components on body composition parameters in a large, wide age range, international twin cohort by using bioelectrical impedance analysis. SUBJECTS: 380 adult twin pairs (230 monozygotic and 150 dizygotic pairs; malefemale ratio, 6832; age years 49.1 ± 15.4; mean ± standard deviation; age range 18-82) were included in the analysis. RESULTS: Heritability was calculated for weight (82%; 95% confidence interval [CI] 78-85), waist and hip circumferences (74%; 95%CI 68-79), body fat percentage (74%; 95%CI 69-79), fat-free mass (74%; 95%CI 69-79) and body mass index (79%; 95%CI 74-83). The completely environmental model showed no impact of shared environmental effects on the variance, while unshared environmental effects were estimated as between 18% and 26%. CONCLUSIONS: BIA findings provide additional evidence to the heritability of anthropometric attributes related to obesity and indicate the practical value of this simple method in supporting efforts to prevent obesity-related adverse health events.