Coronary Heart Disease among Minnesota Business and Professional Men Followed Fifteen Years

Abstract

Relative weight, body fatness (skinfold thickness), blood pressure, and serum cholesterol are reported from 281 Minnesota business and professional men, initially clinically healthy and aged 45 to 55, who were followed by annual examinations since the winter of 1947-48. In 15 elapsed years, coronary heart disease developed definitely in 32 men and possibly in 16 other men. The incidence of coronary heart disease tended to be higher among men above the median at first examination in relative weight, body fatness, systolic and diastolic blood pressure, and serum cholesterol concentration but these segregations were not statistically significant except with serum cholesterol, which was associated with p < 0.001. The data for the last pre-disease year on the men who developed coronary heart disease showed a significant relationship between incidence and systolic blood pressure as well as for cholesterol. Average data over all pre-disease years showed significantly reduced risk among the men in the bottom quartile for diastolic as well as for systolic blood pressure, while the cholesterol level was significantly prognostic over the entire range of that variable. The few men who developed coronary heart disease with low cholesterol values tended to be in the top 20 per cent of the distribution of blood pressure or relative weight or both. Relative weight showed a high but still imperfect correlation with body fatness. Arterial blood pressure tended to be elevated in extremely obese or grossly overweight men. Serum cholesterol was not significantly related to any of the other variables. Men who developed coronary heart disease tended to have low values for cholesterol in the alpha-lipoprotein fraction in the serum but the ratio of cholesterol in the alpha- to the beta-lipoprotein fraction of the serum was no more prognostic than total cholesterol alone. Comparison with similar follow-up data from Framingham, Massachusetts, Albany, New York, and Chicago, show a high degree of concordance. In all series relative weight had least significance and the incidence of coronary heart disease rose continuously with the serum cholesterol level. With men classified according to pre-disease cholesterol level, about 80 per cent of the total variance in relative subsequent risk is accounted for by regression of risk on the cholesterol value raised to any power from 2 to 3 and the correlation between observed and predicted relative risk is of the order of r = 0.9.