STRONG MEDIATORS OF SOCIAL INEQUALITIES IN RISK OF ISCHEMIC-HEART-DISEASE - A 6-YEAR FOLLOW-UP IN THE COPENHAGEN MALE STUDY

Objective. Large social inequalities exist in risk of ischaemic heart disease (IHD) in Western populations; inequalities which are only litt le accounted for by established risk factors. We wished to find out if some newly identified cardiovascular risk factors in concert with est ablished factors might contribute further to the explanation. Design a nd Setting. A 6-year follow-up in the Copenhagen Male Study. Subjects. Some 2974 males aged 53-75 years (mean 63) without overt cardiovascul ar disease were included in the study. Potential confounders included were: alcohol, physical activity, smoking, serum lipids, serum cotinin e, serum selenium, lifetime occupational exposure to soldering fumes a nd organic solvents, body mass index, blood pressure, hypertension, us e of sugar in hot beverages, use of diuretics, and Lewis phenotypes. M ain Outcome Measures. During the 6-year follow-up period (1985/1986-19 91), 184 men (6.2%) had a first IHD event. Compared to higher social c lasses (classes I, II and III), lower classes (classes IV and V) had a significantly (P < 0.05) increased risk of IHD; age-adjusted relative risk (RR) with 95% confidence limits was 1.44 (1.1-1.9), P = 0.02. Af ter multivariate adjustment for age, blood pressure, serum lipids, phy sical activity, and smoking, the RR dropped to 1.38 (1.0-1.9), P = 0.0 5. Some newly identified risk factors were significantly associated wi th increased risk of IHD as well as with low social class: a low serum selenium concentration, a low level of leisure time physical activity in midlife, long-term exposure to soldering fumes, and abstention fro m or a low consumption of wine and strong spirits. After adjustment fo r these factors also, the RR dropped to 1.12 (P = 0.54). Conclusions. The results of this study suggest that potentially modifiable risk fac tors associated with lifestyle and working environment are strong medi ators of social inequalities in risk of ischaemic heart disease.