RELATIONSHIP BETWEEN SERUM-CHOLESTEROL AND THE RISK OF ACUTE MYOCARDIAL-INFARCTION IN A SCREENED COHORT IN OKINAWA, JAPAN

Coronary heart disease (CHD) is rare in Japanese subjects and serum ch olesterol levels are low. However, no data have been published relatin g the effect of serum cholesterol levels to the incidence of acute myo cardial infarction (AMI) in Japan. Data from a large community-based m ass screening registry are available for the geographically isolated i sland of Okinawa, Japan (1980 census: 1.11 million). A total of 38,053 participants (17,859 men and 20,194 women) whose serum cholesterol le vels were determined in the 1983 mass screening were examined to deter mine whether they had experienced AMI. Every case of AMI that occurred during a 3-year period (1 April 1988 to March 1991) throughout Okinaw a was recorded in a separate registry. The total number of cases of AM I 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 t he mass screening registry. The cumulative incidence of AMI increased with the serum level of cholesterol: 42.1 (serum cholesterol less than or equal to 167 mg/dl), 133.5 (serum cholesterol 168-191 mg/dl), 188. 9 (serum cholesterol 192-217 mg/dl), and 323.0 (serum cholesterol grea ter than or equal to 218 mg/dl) per 100,000 screened subjects. Multipl e logistic analysis was conducted to examine the effect of serum chole sterol 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 le vels of cholesterol was 1.66 (1.29-2.15) with a reference serum choles terol level of less than or equal to 167 mg/dl. The risk of AMI increa sed in proportion to the serum level of cholesterol. Serum cholesterol is an independent predictor of AMI in Okinawa, Japan.