Twelve-year trends in cardiovascular disease risk factors in the Minnesota Heart Survey. Are socioeconomic differences widening?

BACKGROUND: Inverse associations of educational level and household income (as proxy indicators of socioeconomic status) with cardiovascular disease risk factors are fairly well established. Whether differences in cardiovascular disease risk factors across education or income levels have widened in the last decade remains an issue of considerable public health importance.

METHODS: Analysis by mixed-regression models of trends in cardiovascular disease risk factors, in population-based samples (n = 3334 in 1980-1982, n = 4538 in 1985-1987, and n = 4517 in 1990-1992) of Minneapolis-St Paul residents 25 to 74 years old.

RESULTS: Education level was inversely related to serum cholesterol level, systolic blood pressure, smoking prevalence, and body mass index and positively related to leisure-time physical activity and health knowledge in both sexes. Household income was inversely associated with systolic blood pressure and body mass index in women and with smoking prevalence in both sexes. Income level was positively associated with leisure-time physical activity and health knowledge in both sexes. There were overall favorable downward secular trends in serum cholesterol level and systolic blood pressure, favorable upward trends in health knowledge, and unfavorable upward trends in body mass index across all socioeconomic status groups. Throughout the decade, trends in smoking prevalence differed by education level in men (P = .01), such that declines were observed only in those with a college degree or some college education. With respect to trends in leisure-time physical activity, there were greater gains among men with low socioeconomic status (P = .03 for education; P = .02 for income) and among less affluent women (P = .001).

CONCLUSIONS: These data support the inverse association between socioeconomic status and cardiovascular disease risk factors but suggest no widening (with the exception of smoking by education level in men) of socioeconomic differences in risk factor trends during the last decade in a representative sample of the Minneapolis-St Paul population.