Low-density lipoprotein cholesterol concentrations and death due to intraparenchymal hemorrhage: the Ibaraki Prefectural Health Study

Abstract

Background: Few studies have examined the association between low levels of low-density lipoprotein (LDL) cholesterol and risk of intraparenchymal hemorrhage.

Methods and results: A total of 30 802 men and 60 417 women, 40 to 79 years of age with no history of stroke or coronary heart disease, completed a baseline risk factor survey in 1993 under the auspices of the Ibaraki Prefectural Health Study. Systematic mortality surveillance was performed through 2003, and 264 intraparenchymal hemorrhage deaths were identified. LDL cholesterol levels were calculated with the Friedewald formula. Persons with LDL cholesterol > or =140 mg/dL had half the sex- and age-adjusted risk of death due to intraparenchymal hemorrhage of those with LDL cholesterol <80 mg/dL. After adjustment for cardiovascular risk factors, the multivariable hazard ratio compared with persons with LDL cholesterol <80 mg/dL was 0.65 (95% CI 0.44 to 0.96) for those with LDL cholesterol 80 to 99 mg/dL, 0.48 (0.32 to 0.71) for 100 to 119 mg/dL, 0.50 (0.33 to 0.75) for 120 to 139 mg/dL, and 0.45 (0.30 to 0.69) for >/=140 mg/dL. These inverse associations were not altered substantially after the exclusion of persons with hypertriglyceridemia, after analysis with a Cox proportional hazard model with time-dependent covariates, or in sensitivity analysis for the potential effect of competing risks.

Conclusions: Low LDL cholesterol levels are associated with elevated risk of death due to intraparenchymal hemorrhage.