Do physical and chemical working conditions explain the association of social class with ischaemic heart disease?
The aim of this study was to examine whether physical and chemical working conditions explain the association of social class with ischaemic heart disease (IHD). We investigated the issue in a cohort of 2974 males aged 53-75 years (mean 63) free from overt cardiovascular disease. Potential confounders included were: alcohol consumption, physical activity, tobacco smoking, serum cotinine, serum lipids, serum selenium, body mass index, blood pressure, hypertension, social class, and retirement status. During the follow-up period (1985-1986 to 31 December 1991), 184 men (6.2%) had a first IHD event; 44 events were fatal. Compared to higher social classes (classes I, II and III), lower classes (classes IV and V) had a significantly increased risk of IHD (P < 0.05); the age-adjusted relative risk (RR) with 95% confidence limits was 1.44 (1.06-1.95), P = 0.02. Mean who had been occupationally long-term exposed (> or = 5 years) to either soldering fumes or organic solvents had a significantly