Differences in Coronary Heart Disease in Framingham, Honolulu and Puerto Rico

Abstract

An effort to evaluate geographic differences in prevalence and incidence of coronary heart disease in men from Framingham, Japanese from Honolulu, and residents of Puerto Rico was made, using comparable methodology and criteria. The prevalence of CHD was twice as great in Framingham as in Honolulu and Puerto Rico. CHD incidence by ECG alone, by CHD death, or by both was from 2 to 4 times as high in Framingham as in Honolulu and Puerto Rico. There was a striking agreement among the studies with respect to the relationship of baseline characteristics to subsequent incidence of CHD. In particular, all three studies found a positive association of serum cholesterol and blood pressure to subsequent CHD incidence. A similar relationship was encountered with cigarette smoking in Framingham and Honolulu but not in Puerto Rico. All three found little or no relationship to the various measures of clinical and subclinical diabetes. A number of other variables showed relationships that were similar in all three studies. On the other hand, relative weight was a much weaker risk factor in Framingham than in Honolulu or Puerto Rico. Since serum cholesterol levels and the amount of cigarette smoking differ in the three populations it is logical to inquire whether this could account for the differences in CHD incidence. The answer is clear that the average Honolulu Japanese and Puerto Rican has a lower CHD incidence than his counterpart in Framingham. Even after allowing for differences in population characteristics, the difference is statistically significant and about 2-1 in magnitude. This suggests that new factors or explanations should be sought in order to clarify the additional protection against coronary heart disease found in some populations.