Low-density lipoprotein cholesterol and risk of cardiovascular disease in a working population

BackgroundElevated low-density lipoprotein cholesterol (LDL-C) is a well-established risk factor for coronary heart disease, but its role in stroke remains unclear. This study examined the association between LDL-C levels and the risk of cardiovascular disease (CVD) and its subtypes in a large cohort of Japanese workers.MethodsWe analyzed data from 69,605 participants in the Japan Epidemiology Collaboration on Occupational Health study. Baseline LDL-C levels were categorized as <70, 70-99, 100-119, 120-139, 140-159, and ≥160 mg/dL. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsOver a mean follow-up of 8.5 years (range, 0.1-13.4 years), 406 participants developed CVD. Compared with LDL-C levels of 100-119 mg/dL, participants with LDL-C <70 mg/dL had a higher risk of intracerebral hemorrhage (HR, 3.56; 95% CI, 1.31-9.66), whereas no association was observed between LDL-C levels and subarachnoid hemorrhage. For ischemic stroke, a U-shaped association was observed; adjusted HRs (95% CIs) versus 100-119 mg/dL were 2.26 (0.97-5.25), 1.53 (0.92-2.56), 0.95 (0.56-1.60), 1.71 (1.04-2.81), and 1.52 (0.85-2.72) for LDL-C levels of <70, 70-99, 120-139, 140-159, and ≥160 mg/dL, respectively. In contrast, the risk of myocardial infarction increased linearly with increasing LDL-C levels.ConclusionsVery low LDL-C levels were associated with an increased risk of intracerebral hemorrhage, whereas a suggestive U-shaped association was observed between LDL-C levels and ischemic stroke. The risk of myocardial infarction increased with higher LDL-C levels.