ABSTRACT
BACKGROUND: Higher waist circumference and lower hip circumference are both associated with increased cardiovascular disease (CVD) risk, despite being directly correlated. The real effects of visceral obesity may therefore be underestimated when hip circumference is not fully taken into account. We hypothesized that adding waist and hip circumference to traditional risk factors would significantly improve CVD risk prediction. METHODS: In a population-based survey among South Asian and African Mauritians (n = 7978), 1241 deaths occurred during 15 years of follow-up. In a model that included variables used in previous CVD risk calculations (a Framingham-type model), the association between waist circumference and mortality was examined before and after adjustment for hip circumference. The percentage with an increase in estimated 10-year cumulative mortality of >25% and a decrease of >20% after waist and hip circumference were added to the model was calculated. RESULTS: Waist circumference was strongly related to mortality only after adjustment for hip circumference and vice versa. Adding waist and hip circumference to a Framingham-type model increased estimated 10-year cumulative CVD mortality by >25% for 23.7% of those who died and 15.7% of those censored. Cumulative mortality decreased by >20% for 4.5% of those who died and 14.8% of those censored. CONCLUSIONS: The effect of central obesity on mortality risk is seriously underestimated without adjustment for hip circumference. Adding waist and hip circumference to a Framingham-type model for CVD mortality substantially increased predictive power. Both may be important inclusions in CVD risk prediction models.
Subject(s)
Abdominal Fat , Obesity/mortality , Waist Circumference , Waist-Hip Ratio , Adult , Africa/ethnology , Asia/ethnology , Cause of Death , Effect Modifier, Epidemiologic , Female , Humans , Logistic Models , Male , Middle Aged , Population Surveillance , Proportional Hazards Models , Risk Assessment , Risk Factors , Victoria/epidemiologyABSTRACT
The aim of the study was to compare BMI with waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-stature ratio (WSR) as a predictor of diabetes incidence. A total of 1,841 men and 2,104 women of Mauritian Indian and Mauritian Creole ethnicity, aged 25-74 years, free of diabetes, hypertension, cardiovascular disease, and gout were seen at baseline in 1987 or 1992, and follow-up in 1992 and/or 1998. At all time points, participants underwent a 2 h 75 g oral glucose tolerance test. Hazard ratios for diabetes incidence were estimated applying an interval-censored survival analysis using age as timescale. Six hundred and twenty-eight individuals developed diabetes during the follow-up period. Multivariable adjusted hazard ratios for diabetes incidence corresponding to a 1 s.d. increase in baseline BMI, WC, WHR, and WSR for Mauritian Indians were 1.49 (1.31-1.71), 1.58 (1.38-1.81), 1.54 (1.37-1.72), and 1.61 (1.41-1.84) in men and 1.33 (1.17-1.51), 1.35 (1.19-1.53), 1.39 (1.24-1.55), and 1.38 (1.21-1.57) in women, respectively; and for Mauritian Creoles they were 1.86 (1.51-2.30), 2.07 (1.68-2.56), 1.92 (1.62-2.26), and 2.17 (1.76-2.69) in men and 1.29 (1.06-1.55), 1.27 (1.04-1.55), 1.24 (1.04-1.48), and 1.27 (1.04-1.55) in women. Paired homogeneity tests showed that there was no difference between BMI and each of the central obesity indicators (all P > 0.05). The relation of BMI with the development of diabetes was as strong as that for indicators of central obesity in this study population.
