Gender-modulated risk of coronary heart disease, diabetes and coronary mortality among Turks for three major risk factors, and residual adiposity risk

BACKGROUND: We determined the proportion of the effects of body mass index (BMI) or its categories on cardiometabolic outcomes mediated through systolic blood pressure (SBP), total cholesterol and fasting glucose. METHODS: Cox regression analyses were performed for incident outcomes among Turkish Adult Risk Factor study participants in whom the three mediators had been determined (n = 2158, age 48.5 ± 11 years). Over a mean 10.2-years’ follow-up, new coronary heart disease (CHD) developed in 406, diabetes in 284 individuals, and 149 CHD deaths occurred. RESULTS: Hazard ratios (HR) of BMI for incident diabetes were no more than marginally attenuated by the 3 mediators including glucose, irrespective of gender. Compared to “normal-weight”, sex- and age-adjusted RRs for incident CHD of overweight and obesity were 1.40 and 2.24 (95 % CI 1.68; 2.99), respectively, in gender combined. Only three-tenths of the excess risk was retained by BMI in men, six-tenths in women. No mediation of glycemia was discerned in males, in contrast to greatest mediation in females. HR of age-adjusted continuous BMI was a significant but modest contributor to CHD mortality in each gender. While the BMI risk of CHD death was abolished by mediation of SBP in men, HR strengthened to over two-fold in women through mediation of fasting glucose. CONCLUSIONS: Mediation of adiposity by 3 traditional factors exhibited among Turkish adults strong gender dependence regarding its magnitude for CHD risk and the mediation by individual risk factors. Retention of the large part of risk for diabetes in each sex and for CHD in women likely reflects underlying autoimmune activation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12902-016-0134-6) contains supplementary material, which is available to authorized users.