Occupation, marital status, and low-grade inflammation: mutual confounding or independent cardiovascular risk factors?

OBJECTIVE We explored the relationships between inflammatory proteins, occupation, and marital status, and their independent associations with incidence of cardiovascular disease (CVD). METHODS AND RESULTS Five inflammation-sensitive proteins (ISPs) (fibrinogen, ceruloplasmin, haptoglobin, alpha1-antitrypsin, orosomucoid) were measured in 6075 apparently healthy men. Incidence of coronary events and stroke was followed over 18 years in relation to occupation and marital status. All ISPs showed higher concentrations in divorced men and in manual workers. Except for fibrinogen, this remained significant after adjustments for confounding factors. Adjusted for traditional cardiovascular risk factors, incidence of coronary events was significantly increased in unskilled manual workers and in divorced men. The relative risks were slightly reduced after further adjustments for ISPs (from 1.79 to 1.70 in unskilled manual workers; from 1.58 to 1.51 in divorced men). All ISPs were significantly associated with incidence of coronary events, after adjustments for traditional risk factors. This relationship was essentially unchanged after further adjustments for occupation and marital status. CONCLUSIONS Inflammation could contribute to, but not fully explain, the increased cardiovascular risk in manual workers and divorced men. Although the ISPs vary greatly by occupational and marital status, this does not confound the relationship between ISPs and incidence of CVD.