Agreement of body adiposity index (BAI) and paediatric body adiposity index (BAIp) in determining body fat in Brazilian children and adolescents

Abstract

ObjectiveTo evaluate agreement of the body adiposity index (BAI) and paediatric body adiposity index (BAIp) in estimating body fat compared with dual-energy X-ray absorptiometry (DXA) and to propose cut-off points for these indices to classify excess adiposity in Brazilian children and adolescents.DesignCross-sectional study. Measures of weight, height, hip circumference, BMI and body fat percentage (%BF) assessed by DXA were taken, and BAI and BAIp were calculated. The Bland–Altman plot was used to estimate agreement between the methods, and the receiver-operating characteristic curve to determine the cut-off points for BAI and BAIp per age and sex in comparison with DXA.SettingViçosa, Minas Gerais, Brazil.SubjectsChildren and adolescents aged 8–19 years (n 1049).ResultsOf the children and adolescents, 52·4 % were girls. BAI and BAIp had satisfactory performance by the receiver-operating characteristic curve, except for the 18–19 years age group, whose BAIp had better predictive capacity than BAI. The agreement analysis showed that BAI overestimated %BF by 2·64 %, on average, using DXA; while BAIp underestimated %BF by 3·37 %.ConclusionsBAI and BAIp showed low agreement with the body fat obtained by DXA, requiring caution when interpreting body composition data in children and adolescents.

Prediction of body fat in adolescents: validity of the methods relative fat mass, body adiposity index and body fat index

“…However, this study used skinfold measurements as a reference method to validate the model, which is a limitation in studies of this nature. Other studies have observed a high proportion of bias and low agreement between the %BF predicted by DXA and the %BF predicted by BAI in Brazilian children and adolescents [15,16].…”

“…A positive point of the present study was the establishment of objective criteria to validate the analyzed equations. Previously published studies have also carried out similar statistical analyses [11,15,29]. However, they have not clearly defined the validity criteria.…”

“…In the literature, there are results showing high bias and non-validity of BAI for prediction of %BF in both adults and adolescents [11,15]. One study found that the agreement of BAI was higher than the correlation between BMI and %BF by DXA in American-European adults by Lin's CCC.…”

“…Regarding the RFM method, greater accuracy was observed in relation to BMI in American boys (82.3% vs. 73.9%) and less accuracy than BMI in American girls (89.0% vs. 92.6%) participants from the NHANES 1999-2006 [17]. A recent study with Brazilian adolescents found that the RFM had high specificity for the %BF classification, however, the sensitivity was low [15]. This result conflicts with the results of Woolcott and Bergman [17] who found that the RFM was more accurate than the BMI for identifying overweight and obesity in boys.…”

Anthropometric indicators associated with childhood obesity. Is it time for a BMI successor?

“…Naukowcy zamiennie stosują BAI i BAIp do oceny zawartości tkanki tłuszczowej u dzieci. Po przebadaniu 1049 osób w wieku od 8 do 19 lat wykazano, że Pediatric Body Adiposity Index wykazał niską zgodność z zawartością tkanki tłuszczowej obliczonej za pomocą DXA [65]. Autorzy wykazali, że BAI przeszacował procentową zawartość tkanki tłuszczowej średnio o 2,64% w porównaniu do wartości uzyskanych za pomocą DXA, natomiast BAIp zaniżył o 3,37%.…”