Effects of Low-density Lipoprotein Cholesterol on Cardiovascular Disease and All-cause Mortality in Elderly Patients (≥75 years old)

PURPOSE Although increased low-density lipoprotein cholesterol (LDL-C) is one of the major risk factors for the cardiovascular disease (CVD), the associations of LDL-C with CVD and all-cause mortality are unclear in elderly (≥75 years) individuals. METHODS A total of 3674 individuals aged 75 or older underwent medical examinations at the Kailuan Group from 2006 to 2007, including 3478 males (94.67%) and 196 females (5.33%). Participants were divided into three groups based on the LDL-C level: the ideal level (LDL-C < 100 mg/dl), appropriate level (100 mg/dl ≤ LDL-C < 130 mg/dl) and elevated level (LDL-C ≥ 130 mg/dl) groups. CVD and all-cause mortality events were recorded during the follow-up period. The Cox proportional hazards regression model was applied to evaluate the effects of LDL-C on CVD and all-cause mortality events. RESULTS The average follow-up time was 9.87 ± 3.60 years. After adjustment for confounding factors, the multivariate Cox proportional hazards regression model showed that the CVD risk in the elevated level group was 1.45 (95% CI, 1.08-1.95), acute myocardial infarction risk was 1.96 (95% CI, 1.19-3.24) and all-cause mortality risk was 1.18 (95% CI, 1.02-1.37) compared with those in the ideal level group. For every standard deviation increase in LDL-C levels, the CVD risk increased by 10%, acute myocardial infarction risk increased by 21% and all-cause mortality event risk increased by 4%. No association was observed between elevated LDL-C levels and the risk of stroke. CONCLUSIONS In the sample of older Chinese individuals investigated in the present study, elevated LDL-C levels (≥130 mg/dl) are a risk factor for CVD and all-cause mortality.