To explore the applicability of body adiposity index (BAI) among Chinese people in the Shanghai area.

487 subjects aged from 20 to 81 years in the Shanghai area were included in the study and analysis was made in the whole group as well as in the subgroups divided by gender (male/female), age (60 years old) and BMI (24 kg/m²) from 2013 to 2014 .Magnetic resonance image(MRI) technology was used to measure subcutaneous adipose area (SA), visceral adipose area (VA), femoral adipose area (FA) and subcutaneous and visceral adipose area (SAVA). Height, weight, waist circumference (WC), hip circumference (Hip) and blood pressure (BP) were measured and waist hip ratio (WHR), body mass index (BMI) and body adiposity index (BAI) was calculated using the following formula: BAI=[Hip circumference (cm)/height (m)^1.5]-18. Blood glucose, blood lipid and other biochemical parameters were tested. We assessed the difference between the two groups with Student’s t test for independent samples and we analyzed the correlation relationships between BAI and BMI with regional fat content using multiple linear regression analysis.

Overall the correlation coefficients between WC and WHR were higher with BMI (r=0.68, P<0.01; r=0.73, P<0.01) than with BAI (r=0.59, P<0.01; r=0.69, P<0.01). BAI and BMI correlated significantly with SA (r=0.78 for BAI, r=0.58 for BMI, P<0.01), VA(r=0.44 for BAI, r=0.55 for BMI,P<0.01), FA(r=0.63 for BAI, r=0.40 for BMI, P<0.01) and SAVA (r=0.78 for BAI, r=0.68 for BMI, P< 0.01). In age, gender and BMI stratified analysis, BAI showed a weaker correlation with SA and SAVA than BMI only in the male group(BAI: r=0.62, 0.67, BMI: r=0.65, 0.73; all P<0.001), but BAI was more correlated with VA than BMI in the female group (BAI: r=0.60, BMI: r=0.52, all P<0.001). In the multiple linear regression model with BAI and BMI as the dependent variables, adjusted by gender and age, the contribution rates of BAI and BMI, were respectively 70%, 51% for SAVA and they differed significantly (P<0.01).

In the whole group except the male subgroup, BAI is better than BMI in estimating body fat content in the Shanghai area. This indicates that BAI could be cautiously adopted to predict the body fat in such situations without accurate weighing apparatus or without knowing the exact body weight.

Body adiposity index; Body mass index; Magnetic resonance image; Body fat content