Test-retest reliability of air displacement plethysmography (BOD POD) in the adult healthy Indian male population

ABSTRACT

Objectives: Several studies have shown that air displacement plethysmography (ADP) has excellent reliability, accuracy and precision in body fat percentage (BF%) measurement, but its reliability has not been assessed in the Indian population. Thus, this study aimed to determine the test-retest reliability of BF% by ADP in healthy Indian men. Materials and Methods: A total of 74 healthy Indian men (>18 years old) belonging to different parts of India voluntarily participated in the study and completed multiple trials to determine BF% immediately after the initial measurements. All tests were performed according to the manufacturer’s instructions. Results: A paired t-test showed no significant differences in body volume (BV) (P = 0.53), body density (BD) (P = 0.39) and BF% (P = 0.27) between trials 1 and 2. However, there was a significant decrease in body mass (BM) observed between trials 1 and 2 (P = 0.0001) which did not influence reliability. A significant intraclass correlation was observed for BM (intraclass correlation 1 [ICC1] = 1, P <0.001), BV (ICC1 = 1, P < 0.001), BD (ICC1 = 0.996, P < 0.001) and BF% (ICC1 = 0.995, P < 0.001) between the initial test and retest trial. The third assessment of BF% was performed when the initial trial difference was greater than 1% point. Significant intraclass correlations were also observed for pairs with maximum and minimum differences. Conclusion: ADP appears to be a reliable measure for determining the BF% of the Indian adult male population, and conducting multiple trials are necessary to detect small differences.