Changes in Coronary Heart Disease Risk Factors in the 1980s: Evidence of a Male-Female Crossover Effect with Age

The Stanford Five-City Project was initiated in 1978 to evaluate the effects of community-wide health education on coronary heart disease risk factors in two control (San Luis Obispo and Modesto) and two treatment (Monterey and Salinas) cities. This paper examines sex differences in the prevalence of smoking, hypercholesterolemia, and hypertension from the baseline survey in 1979–1980 through the conclusion of the intervention In 1985–1986. Four independent cross-sectional surveys (n = 1,713, 1,709, 1,848, and 1,768) and four repeated surveys of a cohort (n = 817) were conducted. This analysis presents findings separately for a younger age group (25–49 years) and an older age group (50–74 years). Smoking, hypercholesterolemia, and hypertension were more prevalent among younger men than younger women in both treatment and control cities. In general, this excess risk among younger men disappeared or reversed in the older age group. Over the 7-year study, the prevalence of hypertension and smoking decreased for both men and women in all surveys, the prevalence of hypercholesterolemia displayed no definite change, and male/female ratios of risk factor prevalence showed either no change or a slight decrease. This study confirms a higher prevalence of the three major risk factors for coronary heart disease among younger men, with the prevalence of hypercholesterolemia and, to a lesser extent, the prevalence of smoking becoming greater among women than men in the older age group and the prevalence of hypertension becoming equivalent.