Risk Factors for Incidence of Cardiovascular Diseases and All-Cause Mortality in a Middle Eastern Population over a Decade Follow-up: Tehran Lipid and Glucose Study

Abstract

BACKGROUND: To examine the association between potentially modifiable risk factors with cardiovascular disease (CVD) and all-cause mortality and to quantify their population attributable fractions (PAFs) among a sample of Tehran residents. METHODS: Overall, 8108 participants (3686 men) aged≥30 years, were investigated. To examine the association between risk factors and outcomes, multivariate sex-adjusted Cox proportional hazard regression analysis were conducted, using age as time-scale in two models including general/central adiposity: 1)adjusted for different independent variables including smoking, education, family history of CVD and sex for both outcomes and additionally adjusted for prevalent CVD for all-cause mortality 2)further adjusted for obesity mediators (hypertension, diabetes, lipid profile and chronic kidney disease). Separate models were used including either general or central adiposity. RESULTS: During median follow-up of >10 years, 827 first CVD events and 551 deaths occurred. Both being overweight (hazard ratio (HR), 95%CI: 1.41, 1.18-1.66, PAF 13.66) and obese (1.51, 1.24-1.84, PAF 9.79) played significant roles for incident CVD in the absence of obesity mediators. Predicting CVD, in the presence of general adiposity and its mediators, significant positive associations were found for hypercholesterolemia (1.59, 1.36-1.85, PAF 16.69), low HDL-C (1.21, 1.03-1.41, PAF 12.32), diabetes (1.86, 1.57-2.27, PAF 13.87), hypertension (1.79, 1.46-2.19, PAF 21.62) and current smoking (1.61, 1.34-1.94, PAF 7.57). Central adiposity remained a significant positive predictor, even after controlling for mediators (1.17, 1.01-1.35, PAF 7.55). For all-cause mortality, general/central obesity did not have any risk even in the absence of obesity mediators. Predictors including diabetes (2.56, 2.08-3.16, PAF 24.37), hypertension (1.43, 1.11-1.84, PAF 17.13), current smoking (1.75, 1.38-2.22, PAF 7.71), and low education level (1.59, 1.01-2.51, PAF 27.08) were associated with higher risk, however, hypertriglyceridemia (0.83, 0.68-1.01) and being overweight (0.71, 0.58-0.87) were associated with lower risk. CONCLUSIONS: Modifiable risk factors account for more than 70% risk for both CVD and mortality events.