EFFECT OF RISK-FACTORS AND CHANGES IN RISK-FACTORS ON CORONARY MORTALITY IN 3 COHORTS OF MIDDLE-AGED PEOPLE IN EASTERN FINLAND

The association of smoking, serum cholesterol, and blood pressure with coronary mortality and the contribution of changes in these risk fact ors to the decline in coronary mortality was assessed in three cohorts of middle-aged population examined in 1972, 1977, and 1982 in Eastern Finland. A total of 10,758 men and 11,112 women were included in this study. The follow-up time of each subject was 8 years. Age-adjusted c oronary mortality decreased from 54 per 10,000 person-years in the 197 2 cohort to 30 per 10,000 person-years in the 1982 cohort among men an d from eight per 10,000 person-years to four per 10,000 person-years a mong women in the 1972 and 1982 cohorts, respectively. Concomitantly w ith the decrease in coronary mortality, there was a marked decrease in cardiovascular risk factors. Among men, the age- and geographic area- adjusted hazard rate ratio of coronary mortality between 1972 and 1982 cohorts was 0.52 (95% confidence interval (CI) 0.38-0.72). After furt her adjustment for smoking, serum cholesterol, and blood pressure, the hazard rate ratio was 0.74 (95% CI 0.54-1.02). Among women, the corre sponding hazard rate ratios were 0.49 (95% CI 0.21-1.12) and 0.73 (95% CI 0.30-1.71), respectively. Therefore, it can be estimated that in b oth sexes nearly half of the decrease in coronary mortality hazard was associated with the changes in risk factors. The fall in serum choles terol level among men and the decrease in blood pressure among women c ontributed most of the decrease in coronary mortality hazard.