A long-term follow-up study of serum lipid levels and coronary heart disease in the elderly.Chin Med J (Engl) 2004; 117(2):163-7CM
It is still controversial whether or not the correlation between lipid abnormality and coronary heart disease (CHD) becomes weaker in the elderly, and whether patients above 80 years old still benefit from lipid management for the secondary prevention of CHD. The purpose of this study is to assess the correlation between hyperlipidemia and the risk of CHD events in the elderly, and to determine if it is appropriate to use lipid-lowering drugs in those aged above 80, as prescribed by the recommended guidelines for lipid management.
One thousand two hundred and eleven retirees, mainly males (92%), aged 70 +/- 9 years, were enrolled in this study. Lifestyle habits and medical history were recorded via questionnaires. During the period 1986 - 2000, all subjects participated in an annual physical examination with a blood chemistry survey. The mean follow-up period was 11.2 years. Subjects with incidental illnesses, especially cardiovascular diseases, were diagnosed or treated promptly. Serum lipid parameters, including total cholesterol (TC), low and high-density lipoprotein cholesterol (LDL-C and HDL-C) and triglyceride (TG) levels were analyzed according to standardization of lipid and lipoprotein measurements. The association between lipid levels and the prevalence of acute myocardial infarction (AMI) or coronary death was analyzed statistically.
Lipid abnormalities occurred in 2/3 of the 1211 subjects. The most common lipid disorder was high TC and high LDL-C, which was much more prevalent than high TG. Among the subjects, 51.6% had TC levels above 5.2 mmol/L. Mean TC and LDL-C reached peak levels in the 65 - 74 age group without significant decrease until ages over 90. The cumulative total number of deaths due to various causes was 397 in the 15-year follow-up period, with the mortality rate in the high lipid group slightly lower than that in the normal lipid group (30.6% vs 35.3%), although the difference was not significant (P = 0.1931). However, there were more cases of coronary death in the high lipid group than in the normal lipid group (7.9% vs 4.6%, P = 0.0045). When examining AMI survivors, more AMI cases were found in the high lipid group than in the low lipid group (20.9% vs 11.4%, P < 0.0001). The cumulative number of coronary deaths was 89 (with 88 cases above age 70), and the total number of CHD cases was 214 (17.7% of the whole group). Logistic regression analysis reveals that age, hypertension, LDL-C, and HDL-C are important risk factors for CHD. Lifestyle changes were common, but only 45% of the hyperlipidemic cases received drug treatment. Statins were commonly used only in recent years.
The above results show that high TC and LDL-C levels are correlated with a high CHD risk even in people over 80. For elderly patients with clinical CHD and an aggregation of CHD risk factors, cholesterol-lowering therapy might be considered if the general health of the patient makes this permissible.