Income and heart disease: Neglected risk factor

Objective To determine the unadjusted and adjusted effects of income on heart disease; its main disease intermediary, high blood pressure; and its main behavioural risk factors, smoking and physical inactivity. Design Random-digit dialing telephone survey collected through the Canadian Community Health Survey by Statistics Canada. Setting Saskatchewan. Participants A total of 27 090 residents aged 20 years and older; each health region in Saskatchewan was represented. Main outcome measures Overall, 178 variables related to demographic characteristics, socioeconomic factors, behaviour, life stress, disease intermediaries, health outcomes, and access to health care were analyzed to determine their unadjusted and adjusted effects on heart disease. Results The mean age of the sample was 52.6 years. Women represented 55.9% of the sample. Most respondents were married (52.3%) and had some postsecondary or graduate education (52.5%). The mean personal income was $23 931 and the mean household income was $37 533. All models statistically controlled for age. Five covariates independently associated with heart disease included high blood pressure, household income of $29 999 or less per year, being a daily smoker, male sex, and being physically inactive. Five covariates independently associated with high blood pressure included being overweight or obese, being a daily smoker, household income of $29 999 or less per year, male sex, and being physically inactive. Five covariates independently associated with daily smoking included being a visible minority, household income of $29 999 or less per year, not being overweight or obese, education level of less than secondary school, and male sex. Six covariates independently associated with physical inactivity included being a visible minority, being overweight or obese, education level of less than secondary school, male sex, household income of $29 999 or less per year, and being a daily smoker. Conclusion Household income was strongly and independently associated with heart disease; its main disease intermediary, high blood pressure; and its main behavioural risk factors, smoking and physical inactivity. Income inequality is a neglected risk factor worthy of appropriate public debate and policy intervention.