The contribution of metabolic risk factors to cardiovascular mortality in Golestan cohort study: population attributable fraction estimation

Background Cardiovascular diseases (CVDs) are the leading causes of global mortality and disability. Several studies demonstrated that metabolic risk factors increase cardiovascular mortality. The aim of this study is to examine CVDs deaths and population attributable fractions (PAFs) of their metabolic risk factors in Iran. Methods This is a study on 8,621 participants aged 45-75 years and older, recruited in the repeated measurement phase of the Golestan cohort study (GCS) in northeast of Iran. The Cox proportional hazards model was used to determine the adjusted hazard ratios (HRs). PAFs were calculated to enumerate CVDs mortality avoidable in the population if metabolic risk factors were eliminated. Results The mortality of CVDs was attributable to metabolic factors, including high waist circumference (PAF, 28%, [95% CI: 16%-38%]), high fasting blood sugar (FBS) (20%, [15%-24%]), overweight and obesity (19%, [8%-28%]), high blood pressure (16%, [11%-21%]), high low-density lipoprotein cholesterol (LDL-C) (8%, [1%-15%]), and high triglyceride (TG) (7%, [3%-11%]). Collectively, these metabolic risk factors accounted for 50% of CVDs deaths. Females (67%, [50%-78%]) had a higher joint PAF of metabolic risk factors compared to males (43%, [27%-55%]). Conclusions The pattern of CVDs mortality attributable to metabolic risk factors in this study is not the same as similar studies in other parts of the world and previous studies in Iran. It is imperative that CVDs risk factors be specifically evaluated and addressed in various populations due to variety in geographical and temporal patterns in contribution of metabolic risk factors to CVD mortality.