Primary cardiovascular events and serum lipid levels in elderly Japanese with hypercholesterolemia undergoing 6-year simvastatin treatment: a subanalysis of the Japan lipid intervention trial.
OBJECTIVE
To determine the relationship between serum lipid levels and the incidence of coronary events in older Japanese hypercholesterolemic patients without prior coronary heart disease (CHD).


METHODS
Post hoc subanalysis of the results in the Japan Lipid Intervention Trial.


METHODS
A large-scale cohort observational study conducted throughout Japan.


METHODS
Men aged 35 to 70 and postmenopausal women younger than 70 with serum total cholesterol (TC) level of 220 mg/dL or greater treated for 6 years with low-dose simvastatin (52,421 total patients). After exclusion of 5,127 patients because of prior CHD and 4,934 patients because of incomplete data, 42,360 patients were divided into an older (9,860 patients, aged 65-70, mean age 67.1) and younger (32,500 patients, younger than 65, mean age 54.9) group and analyzed.


METHODS
Fasting serum lipid levels were measured every 6 months. Major coronary events, including fatal or nonfatal myocardial infarction, and sudden cardiac death as the primary endpoint and other cardiovascular diseases, including onset of angina pectoris, cerebrovascular events, and any causes of death, as the secondary endpoints were monitored.


RESULTS
Simvastatin treatment in older patients was as safe and effective as in younger patients. Incident rates of major coronary events were 1.30 per 1,000 patient-years in the older group and 0.80 per 1,000 patient-years in the younger group. The incidence of a major coronary event was correlated to serum TC and low-density lipoprotein cholesterol (LDL-C) levels in both groups. The absolute risk of major coronary events in the older group was higher than in the younger group at any level of LDL-C, whereas the relative risk increased by 1.7% with an elevation of each 1 mg/dL LDL-C level in both groups. In the older group, the risk of major coronary events also increased as triglyceride level increased, whereas the risk decreased as high-density lipoprotein cholesterol level increased above 60 md/dL.


CONCLUSIONS
The LDL-C level-dependent increase of relative risk of CHD was similar in elderly and younger patients, whereas the absolute risk at any LDL-C level in elderly patients was higher than in younger patients.
Horiuchi
Hisanori
H
Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Kita
Toru
T
Mabuchi
Hiroshi
H
Matsuzaki
Masunori
M
Matsuzawa
Yuji
Y
Nakaya
Noriaki
N
Oikawa
Shinichi
S
Saito
Yasushi
Y
Sasaki
Jun
J
Shimamoto
Kazuaki
K
Itakura
Hiroshige
H
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000924:Anticholesteremic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001213:Asian / Q000706:statistics & numerical data; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D002561:Cerebrovascular Disorders / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control; D003327:Coronary Disease / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control; D005260:Female; D006254:Hawaii / Q000453:epidemiology; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000188:drug therapy* / Q000453:epidemiology; D015994:Incidence; D007564:Japan / Q000208:ethnology; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012306:Risk; D019821:Simvastatin / Q000009:adverse effects / Q000627:therapeutic use*; D016019:Survival Analysis
D000924:Anticholesteremic Agents; D008055:Lipids; D019821:Simvastatin