P6224The combined influence of waist and hip circumference on mortality risk in a large cohort of European and Australian adults: moving beyond BMI, Waist and WHR as measures of obesity

Abstract

Abstract Background Previous research has demonstrated that waist circumference (WC) and hip circumference (HC) are both important predictors of mortality, independent of established risk factors. Their combined influence on risk, and whether they are superior to established obesity measures, has not been thoroughly examined in large cohorts. Purpose We investigated whether WC and HC are better joint predictors of all-cause and cardiovascular disease (CVD) mortality than individual measures of obesity: WC, HC, waist hip ratio (WHR), waist-to-height ratio (WHtR), a body shape index (ABSI), and body mass index (BMI). Methods We used data from 90,487 males and females, 25–74 years of age with no prior history of CVD, from the MOnica Risk, Genetics, Archiving and Monogram (MORGAM) project. Hazard mortality ratios (HR) were estimated using sex-specific Cox models stratified by cohort/country, with age as the time scale. Obesity measures were categorized based on sex specific sample means and standard deviations (SD). All final fully adjusted models included baseline age, total and HDL cholesterol, systolic blood pressure,antihypertensive drugs, current smoker and diabetes. Results During a mean follow-up of 11 years, 9105 all-cause and 2577 CVD deaths were recorded. All obesity measures were found to be associated with all-cause and CVD death after taking account of known CVD risk factors, with the strongest statistical evidence of associations seen for WC and HC combined and ABSI. J- or U-shaped associations with mortality were observed for BMI, WC, HC and WHtR for both males and females, and WHR and ABSI for males. Monotonic associations with mortality were observed for WHR and ABSI for females. For WC and HC combined, HC was an important predictor of death among those with smaller WC (≤1 SD above the mean: below 99cm in women and 106cm in men), with larger HCs associated with reduced risk. No additional increase in mortality risk was found to be associated with HC for those with a WC >1SD above the mean. Of those who would not have been identified as being at higher risk based on their WC alone, 55.7% (n=8350) of females and 30.6% (n=4510) of males are identified as being at higher risk when their smaller HC is taken into consideration. Conclusion The use of single measurements of obesity such as BMI, WC or WHR does not capture the complex relationship between body shape and risk of premature death. Both WC and HC, but not as a ratio, should be used by clinicians to help identify those at increased risk of premature death. Acknowledgement/Funding Individual grants to included cohorts