Can cardiovascular risk factors and lifestyle explain the educational inequalities in mortality from ischaemic heart disease and from other heart diseases? 26 year follow up of 50,000 Norwegian men and women

Abstract

Objective: Investigate the degree to which smoking, physical activity, marital status, BMI, blood pressure, and cholesterol explain the association between educational level and ischaemic heart disease (IHD) mortality and other forms of cardiovascular mortality, with main focus on IHD mortality.

Design: Prospective health examination survey study conducted in the period 1974-78.

Setting: Oppland, Sogn og Fjordane, and Finnmark counties in Norway.

Participants: The sample comprised 22,712 men and 21,972 women, aged 35-49 at screening. The subjects were followed up with respect to mortality throughout year 2000.

Main results: 4342 men and 2164 women died during the follow up, 1343 men and 258 women of IHD. IHD mortality risk was higher for people with low education compared with people with high education, and people with low education had more adverse risk factors. After adjustment for smoking the IHD mortality relative risk (RR) with 95% confidence limits, in the low educational group decreased from 1.33 (1.18 to 1.50) to 1.16 (1.03 to 1.31) for men, and from 1.72 (1.23 to 2.41) to 1.58 (1.13 to 2.22) for women. Further adjustment for physical activity, marital status, BMI, blood pressure, and cholesterol reduced the RR to 1.03 (0.91 to 1.17) for men and 1.24 (0.88 to 1.75) for women.

Conclusions: Unfavourable cardiovascular risk factors and high IHD mortality are more prevalent among less educated than their highly educated peers. After simultaneous adjustment for all recorded risk factors, the excess IHD mortality in the low educational groups was reduced by 91% for men and 67% for women.