Comparison of body adiposity index (BAI) and air displacement plethysmograph with estimations of % body fat in adults with Down's syndrome.

BACKGROUND/OBJECTIVES: The aim of this study was to verify the agreement between body fat percentage (%BF) values evaluated by air displacement plethysmograph (ADP) and body adiposity index (BAI) in adults with Down's syndrome (DS).

SUBJECTS/METHODS: Forty-five adults with DS volunteered to participate in this study (19 women; age 28.7±8.5 years and 26 men; age 29.1±8.8 years). The %BF was measured by ADP (%BFADP ) and estimated by anthropometric measures [%BF=(hip circumference/height)1.5 -18] (%BFBAI ). Agreement between methods was evaluated by paired t-test, Pearson's correlation coefficient and Bland-Altman analysis.

RESULTS: Although high correlation coefficients were found between %BFADP and %BFBAI for women (r=0.78, P<0.05) and men (r=0.87, P<0.05), significant differences were observed between methods for both sexes (38.9±8.9 vs 42.5±8.5% for women, and 25.8±11.3 vs 32.6±5.4% for men in %BFADP and %BFBAI , respectively). Moreover, Bland-Altman analysis showed that the mean error estimate was +3.6 (95%CI, -7.59 to 14.79) in women and +6.74 (95%CI, -7.25 to 20.72) in men.

CONCLUSIONS: The results indicate that BAI seems to be a limited method to evaluate %BF in women and in men with DS.