The association between obesity and cardiovascular disease mortality in different strata of socioeconomic position: evidence from pooled Norwegian health surveys

Abstract

Abstract Background Socioeconomic position (SEP) is related to both obesity and cardiovascular disease (CVD). There is little evidence on whether SEP modifies the relation between obesity and CVD. The aim of the study was to investigate whether the association between obesity and CVD mortality is stronger among people with disadvantaged than among people with advantaged life course SEP. Methods Data from Norwegian population-based cardiovascular health surveys (1985–2003), including body mass index and CVD risk factors (cholesterol, blood pressure, smoking, current treatment for hypertension) were linked to socioeconomic indicators from register and census data (1960–90), and to the Cause of Death Registry (up until 2014). The total number of participants was 398 297. Results In comparison with normal weight, the age-adjusted hazard ratios and 95% confidence intervals of CVD mortality among obese participants were 2.39 (2.07–2.75) and 2.08 (1.70–2.53) among men and women with high SEP, respectively and 1.88 (1.60–2.21) and 1.75 (1.43–2.14) among men and women with low SEP. Adjustment for CVD risk factors attenuated the results in a similar manner in all SEP groups, and among both women and men. Conclusion Obesity was consistently associated with a higher risk of CVD mortality, with only minor variation according to SEP. This means that preventing or treating obesity is, for the purpose of reducing CVD risk, equally important for an individual with high or low SEP.