Body roundness index (BRI) and obesity-related anthropometrics: Relationship to visceral adiposity, insulin sensitivity index and cardiometabolic risk.

Aims: Visceral adiposity is an independent risk factor for cardiovascular disease. Traditional anthropometric measures like body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) have limited accuracy, while a newer measure, body roundness index (BRI), is touted as being a better predictor of visceral adiposity but requires further validation. The aim of this study is to compare BRI with other traditional metrics of adiposity: WC, BMI and percentage (%) body fat, visceral adiposity and insulin sensitivity among the multiethnic cohorts in Asia.

Materials and methods: This was a cross-sectional study of 264 young, healthy and normoglycemic adult males (101 Chinese, 85 Malay, 82 South Asian) with ages of 28.4 ± 6.0, 27.6 ± 5.1 and 26.0 ± 4.8 years. Anthropometric measures (BMI, WC, WHR, BRI), bioimpedance analysis (for percentage body fat), MRI-measured visceral and subcutaneous adipose tissue (VAT, SAT), and hyperinsulinaemic-euglycaemic clamp for insulin sensitivity index (ISI) were assessed.

Results: BRI correlated significantly with VAT (r = 0.72), SAT (r = 0.85), and ISI (r = -0.51), but performed similarly to BMI, WC and percentage body fat. BRI showed consistent results across ethnic groups, with the highest VAT correlation in Malays (r = 0.76). Percentage body fat measured by bioimpedance was as effective as Magnetic Resonance Imaging (MRI) in predicting adiposity, while WHR had the weakest correlation with VAT.

Conclusions: BRI, while strongly correlated with visceral adiposity and ISI, does not outperform simpler measures like WC or percentage body fat. Bioimpedance, being non-invasive, demonstrates utility in assessing visceral adiposity in clinical settings. Ethnic-specific thresholds for BRI and WC may improve precision in obesity-related health assessments.