Background A novel obesity classification method has been proposed utilising body mass index (BMI) and waist-height ratio (WHtR) together. However, the utility of this approach is unclear. In this study we compare the metabolic profiles in subjects defined as overweight or obese by both measures. We examine a range of metabolic risk features, pro-inflammatory cytokines, acute-phase response proteins, coagulation factors and white blood cell counts to determine whether a combination of both indices more accurately identifies individuals at increased cardiometabolic risk.

Methods This was a cross-sectional study involving a random sample of 2,047 men and women aged 50–69 years. Metabolic and anthropometric profiles were assessed in study participants. Independent t or Mann-Whitney U tests were used to compare lipid, lipoprotein, blood pressure, glycaemic and inflammatory biomarker levels between BMI and WHtR tertiles. Multinomial logistic regression was performed to determine adverse metabolic feature and biomarker associations with BMI and WHtR groupings.

Results The combination of BMI and WHtR tertiles identified consistent metabolic variable differences relative to those characterised on the basis of one index. Similarly, odds ratios for cardiometabolic risk factors were noticeably increased in subjects classified by both measures when compared to study participants categorised by either BMI or WHtR separately. In a fully adjusted model, only individuals within the highest percentile for both indices displayed a significant and positive association with pre-diabetes (OR: 3.4, 95% CI: 2.0–6.0, P < 0.001).

Conclusion Risk stratification using a composite index may provide a more accurate method for identifying high and low-risk subjects.