Untangling Waist Circumference and Hip Circumference from Body Mass Index with a Body Shape Index, Hip Index, and Anthropometric Risk Indicator

Body mass index (BMI) corrects body weight for height and is well established for diagnosing overweight and obesity and correlating with many medical conditions. Waist circumference (WC) is used to diagnose abdominal obesity. However, the correlation of BMI and WC is high, around 0.9, making the use of BMI and WC in concert challenging. A body shape index (ABSI) is a new measure of risk associated with abdominal size. Derived in 2012, ABSI is analogous to BMI in that it normalizes WC for weight and height (and thus to BMI). A similar derivation led to hip index (HI), normalizing hip circumference for BMI. Hazard ratios (HRs) for univariate risk associations of the independent measures height, BMI, ABSI, and HI can be multiplied to give a combined HR, the anthropometric risk indicator (ARI). Compared to any one anthropometric factor, including BMI and WC, ARI more accurately estimates personalized mortality hazard. Published work on ABSI, HI, and ARI supports their association with many aspects of health, including cardiometabolic conditions related to the metabolic syndrome.