Association of Lipid Profile With Cardiovascular Diseases and All‐Cause Death: A 2‐Decade Follow‐Up of the Tehran Lipid and Glucose Study

BACKGROUND: We investigated the associations between total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, and triglycerides with all-cause and cardiovascular disease death among participants in the TLGS (Tehran Lipid and Glucose Study) cohort. METHODS: We included 8241 participants aged ≥30 years, who were followed until 2018. Lipid profiles were assessed as both continuous and categorical variables (quintiles) using the restricted cubic spline and Cox proportional hazards model. RESULTS: During a median follow-up of 18.1 years, 1002 and 369 individuals died from all causes and cardiovascular disease, respectively. A U-shaped association was found between non-HDL-C and the risk of all-cause death. In the categorical analyses for all-cause death, individuals in quintile 1 of non-HDL-C had a hazard ratio (HR) of 1.35 (95% CI, 1.09-1.68), compared with quintile 2 (reference). Additionally, those in quintiles 1 and 3 of total cholesterol had HRs of 1.34 (95% CI, 1.08-1.67) and 1.25 (95% CI, 1.02-1.55), respectively, relative to quintile 2 (reference). Regarding cardiovascular disease death, linear associations were observed for total cholesterol, low-density lipoprotein cholesterol, and non-HDL-C. In categorical analysis, quintiles 3 and 5 of total cholesterol had HRs of 1.87 (95% CI, 1.30-2.70) and 1.78 (95% CI, 1.25-2.53), respectively, compared with quintile 2 (reference). Furthermore, compared with quintile 1 of low-density lipoprotein cholesterol (reference), individuals in quintiles 3 and 5 had HRs of 1.62 (95% CI, 1.08-2.42) and 1.81 (95% CI, 1.24-2.66), respectively. For non-HDL-C, the HR for quintile 5 was 1.43 (95% CI, 1.00-2.06) compared with quintile 1 (reference). CONCLUSIONS: In the general population, low and high levels of non-HDL-C were associated with an increased risk of all-cause death.