Relationship Between Serum Cholesterol and the Risk of Acute Myocardial Infarction in a Screened Cohort in Okinawa, Japan

Abstract

Coronary heart disease (CHD) is rare in Japanese subjects and serum cholesterol levels are low. However, no data have been published relating the effect of serum cholesterol levels to the incidence of acute myocardial infarction (AMI) in Japan. Data from a large community-based mass screening registry are available for the geographically isolated island of Okinawa, Japan (1980 census, 1.11 million). A total of 38,053 participants (17,859 men and 20,194 women) whose serum cholesterol levels were determined in the 1983 mass screening were examined to determine whether they had experienced AMI. Every case of AMI that occurred during a 3-year period (1 April 1988 to March 1991) throughout Okinawa was recorded in a separate registry. The total number of cases of AMI was 1,021 (674 men and 347 women). Of these, 65 patients (41 men and 24 women) were identified by name, sex, birth date, and zip code in the mass screening registry. The cumulative incidence of AMI increased with the serum level of cholesterol: 42.1 (serum cholesterol < or = 167 mg/dl), 133.5 (serum cholesterol 168-191 mg/dl), 188.9 (serum cholesterol 192-217 mg/dl), and 323.0 (serum cholesterol > or = 218 mg/dl) per 100,000 screened subjects. Multiple logistic analysis was conducted to examine the effect of serum cholesterol on the risk of AMI with adjustment for other variables such as sex, age, systolic and diastolic blood pressure, and proteinuria. The adjusted odds ratio (95% confidence interval) of the observed serum levels of cholesterol was 1.66 (1.29-2.15) with a reference serum cholesterol level of < or = 167 mg/dl. The risk of AMI increased in proportion to the serum level of cholesterol. Serum cholesterol is an independent predictor of AMI in Okinawa, Japan.

Risk Factors and the Incidence of Coronary Artery Disease in Young Middleaged Japanese Men: Results from a 10Year Cohort Study

“…However, the relationship between risk factors and CAD among young middle-aged Japanese men was not examined. In agreement with a number of previous studies, the present study demonstrated that the increase in TC was proportionally associated with a higher incidence of CAD (17,18 (17,18) as well as in a study in Japan, which included the elderly subjects (19). Therefore, the present study has confirmed that TC is a significant risk factor for CAD also in young middle-aged Japanese men.…”

Treatment of Hyperlipidemia from Japanese Evidence

“…After the exclusion of death due to liver disease during the entire follow-up period, increased HR in the lowest TC group disappeared and the HR for total mortality within the first 5 years of follow up in the highest TC group further increased (HR 1.48; 95%CI 1.12-1.96), mainly as a consequence of CHD. These results were similar in gender-specific analysis, and were in good agreement with the Okinawa cohort study where mortality from CVD is the lowest and life expectancy is the highest in Japan 26) . On the other hand, hypercholesterolemia was not a risk factor for stroke, which is in good agreement with the Hisayama Study, an established cohort study 27) , and the mortality from cerebral hemorrhage was even the highest in the lowest TC group in men (HR 3.77; 95% CI, 1.35-10.5).…”

Diagnostic Criteria for Dyslipidemia

“…, MHW Primary Hyperlipidemia 26) , Okinawa cohort 27) and Ehime epidemiological 10) studies and epidemiological studies conducted in 76 workplaces in Japan (the 3M Study) 4) , have confirmed that the relative risk of CAD increases continuously in association with increases in the levels of LDL-C and TC.…”