Gender difference of association between LDL cholesterol concentrations and mortality from coronary heart disease amongst Japanese: The Ibaraki Prefectural Health Study

Abstract

Objective. The aim of this study was to examine whether LDL cholesterol raises the risk of coronary heart disease in a dose-response fashion in a population with low LDL-cholesterol levels. Design. Population-based prospective cohort study in Japan. Subjects and main outcome measures. A total of 30 802 men and 60 417 women, aged 40 to 79 years with no history of stroke or coronary heart disease, completed a baseline risk factor survey in 1993. Systematic mortality surveillance was performed through 2003 and 539 coronary heart disease deaths were identified. Results. The mean values for LDL-cholesterol were 110.5 mg dL-1 (2.86 mmol L-1) for men and 123.9 mg dL -1 (3.20 mmol L-1) for women. Men with LDL-cholesterol ≥140 mg dL-1 (≥3.62 mmol L-1) had two-fold higher age-adjusted risk of mortality from coronary heart disease than did those with LDL-cholesterol <80 mg dL-1 (<2.06 mmol L-1), whereas no such association for women was found. The multivariable hazard ratio for the highest versus lowest categories of LDL-cholesterol was 2.06 (95 percent confidence interval: 1.34 to 3.17) for men and 1.16 (0.64 to 2.12) for women. Conclusion. Higher concentrations of LDL-cholesterol were associated with an increased risk of mortality from coronary heart disease for men, but not for women, in a low cholesterol population. © 2010 Blackwell Publishing Ltd.