Body adiposity index and its correlation with body fat percentage assessed by dual absorciometry X-ray emission in elderly in southern Brazil

Objective: To verify the correlation between the percentage body fat (%body fat) evaluated by the Body Adiposity Index (BAI) and %body fat evaluated by dual-energy X-ray absorptiometry (DXA) in elderly women. Materials and Methods: Cross-sectional study with elderly women submitted to bone densitometry at an imaging clinic in the Northwest part of Rio Grande do Sul (RS) state in Brazil. Sociodemographic data were evaluated through a questionnaire, which was structured by the researchers. The %body fat was evaluated by DXA and BAI. For the BAI calculation, stature was measured using a stadiometer coupled with a scale. Hip circumference was measured with a tape measure at the most protruding part of the hip. The BAI was calculated through an equation (BAI = [Hip / (height x vheight) - 18]. Results: Two hundred and five elderly women, aging 67.3 +/- 5.8 years old, participated in this study. There was a higher prevalence of women with partners (61.5%), retired (90.2%) and with schooling between 4 and 8 years (47.3%). Regarding adiposity, the mean %body fat demonstrated by BAI was 34%, and 40.59% according to the DXA results. The Pearson's correlation was significant and high r=0.714 (p <0.001) and the Intraclass Correlation Coefficient was 0.649 (95% CI, - 0.106 - 0.852) (p<0.001), being considered strong. Conclusion: In this study, the BAI obtained the elderly women in southern Brazil showed a high correlation with the % body fat measured by DXA and can be used as a complementary index to assess the adiposity of this population.