Reyhaneh Rajab Boloukat1, Azra Ramezankhani1, Mitra Hasheminia1, Erfan Tasdighi1, Fereidoun Azizi2, Farzad Hadaegh3. 1. Prevention of Metabolic Disorders Research Center, Research Institute of Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2. Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 3. Prevention of Metabolic Disorders Research Center, Research Institute of Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: fzhadaegh@endocrine.ac.ir.
Abstract
BACKGROUND & AIMS: To determine the association of body mass index (BMI) and central adiposity measures with coronary heart disease (CHD)/stroke, and to quantify the impact of blood pressure, cholesterol and glucose as metabolic mediators on these associations. METHODS: The study population included 4631 Iranian participants (males = 2066) aged ≥40 years. Cox proportional hazard model was used to estimate the hazard ratio (HR) of BMI and central adiposity measures, using continuous and categorical variables, on CHD/stroke, with and without adjustment for three metabolic mediators, to calculate the attenuation of excess risk after adjustment for mediators. RESULTS: During a median follow-up of 12.1 years, 606 and 132 subjects experienced incident CHD and stroke, respectively. In the sex and confounders adjusted model, overweight and obesity were associated with increased risk for CHD (HR: 1.56; 95% CI: 1.26-1.92) and [1.53 (1.21-1.94)], respectively; however, after further adjustment for all the mediators, the result was significant only for overweight status [1.29 (1.05-1.59)]. Considering stroke, a significant risk of 70% (1.05-2.72) was found only among obese population. The percentage of risk mediated by three mediators among obese population was 75.47% and 75.71% for CHD and stroke, respectively. Blood pressure was the most important mediator of obesity, accounting for at least 50% of the excess risk for CHD and 60% for stroke. Considering central obesity measures, in the presences of all mediators, a significant risk for CHD was demonstrated; regarding stroke events, the risk was marginally significant for waist to height [1.02 (0.99-1.05)] and waist to hip ratios [1.02 (1.00-1.05)]. CONCLUSIONS: Overweight and obesity for CHD and, obesity for stroke were associated with increased risk; the negative effect of obesity was potentially ameloriated about 70% after adjustment for mediators. However, overweight status and central adiposity highlighted significant risk that did not decrease after controlling for traditional risk factors.
BACKGROUND & AIMS: To determine the association of body mass index (BMI) and central adiposity measures with coronary heart disease (CHD)/stroke, and to quantify the impact of blood pressure, cholesterol and glucose as metabolic mediators on these associations. METHODS: The study population included 4631 Iranian participants (males = 2066) aged ≥40 years. Cox proportional hazard model was used to estimate the hazard ratio (HR) of BMI and central adiposity measures, using continuous and categorical variables, on CHD/stroke, with and without adjustment for three metabolic mediators, to calculate the attenuation of excess risk after adjustment for mediators. RESULTS: During a median follow-up of 12.1 years, 606 and 132 subjects experienced incident CHD and stroke, respectively. In the sex and confounders adjusted model, overweight and obesity were associated with increased risk for CHD (HR: 1.56; 95% CI: 1.26-1.92) and [1.53 (1.21-1.94)], respectively; however, after further adjustment for all the mediators, the result was significant only for overweight status [1.29 (1.05-1.59)]. Considering stroke, a significant risk of 70% (1.05-2.72) was found only among obese population. The percentage of risk mediated by three mediators among obese population was 75.47% and 75.71% for CHD and stroke, respectively. Blood pressure was the most important mediator of obesity, accounting for at least 50% of the excess risk for CHD and 60% for stroke. Considering central obesity measures, in the presences of all mediators, a significant risk for CHD was demonstrated; regarding stroke events, the risk was marginally significant for waist to height [1.02 (0.99-1.05)] and waist to hip ratios [1.02 (1.00-1.05)]. CONCLUSIONS: Overweight and obesity for CHD and, obesity for stroke were associated with increased risk; the negative effect of obesity was potentially ameloriated about 70% after adjustment for mediators. However, overweight status and central adiposity highlighted significant risk that did not decrease after controlling for traditional risk factors.
Authors: Rebecca Knowles; Jennifer Carter; Susan A Jebb; Derrick Bennett; Sarah Lewington; Carmen Piernas Journal: J Am Heart Assoc Date: 2021-04-19 Impact factor: 5.501