The association between socioeconomic conditions in childhood and risk of self-reported ischemic heart disease in middle-aged Norwegian women. The Norwegian Women and Cancer Study (NOWAC)

Abstract

Background: Ischemic heart disease is one of the leading causes of morbidity and mortality. It is a chronic disease found to be socioeconomically patterned, and declining rates over the past few decades seems to benefit the most advantaged socioeconomic group, creating a greater difference between the most disadvantaged social group and the most advantageous group. Early life exposures have been found to play a key role in development of heart disease. Aim: To examine if there is an association between childhood socioeconomic conditions and self-reported ischemic heart disease in middle-aged Norwegian women. If an association between childhood socioeconomic circumstances and IHD is observed, we will focus on lifestyle factors in childhood and adolescence as potential explanatory factors. Materials and methods: Data was gathered from the Norwegian Women and Cancer Study (NOWAC), a nationwide prospective cohort established in 1991. The sample consists of 77,154 women aged 30-70 years at baseline. Information on childhood socioeconomic conditions, IHD, education, and lifestyle factors both in childhood and adulthood were self-reported in questionnaires. Cross tabulations and Cox proportional hazards regression model were applied as statistical methods. Results: Women having experienced poor (HR=1.50; 95% CI 1.25-1.81) or very poor (HR=1.70; 95% CI 1.08-2.67) childhood socioeconomic conditions had a significantly increased risk of IHD, compared to the women having experienced good socioeconomic conditions in childhood (fully adjusted model). Conclusion: There is an association between childhood socioeconomic conditions and risk of self-reported ischemic heart disease in middle-aged Norwegian women. Lifestyle factors in childhood and adolescence partly explains the association.