Income change at retirement, neighbourhood-based social support, and ischaemic heart disease: results from the prospective cohort study "Men born in 1914".

Retirement from active life often leads to decreased finances and reduced social contact, which may increase ischaemic heart disease (IHD) risk in individuals. We examined whether income evolution during the decade before retirement has an impact on subsequent IHD, and explored the mediating effect of common risk factors and social support from different sources (marriage/cohabitation, support from friends/relatives, and neighbourhood-based social support). We analyzed data from the 1982-1983 prospective cohort study, "Men born in 1914" (n=498, follow-up period=10 years) conducted in Malmö, Sweden, merged with yearly income data for 14 years preceding baseline. Low income 10 years before retirement predicted both higher prevalence of IHD risk factors at retirement, and weaker neighbourhood-based social support. Income 10 years before retirement was a strong predictor of IHD incidence and mortality after retirement, but a significant downward income mobility at retirement did not increase IHD risk. After adjustment, low neighbourhood-based social support increased the risk of IHD incidence and mortality, and mediated 7-8% of the income effect. In conclusion, income 10 years before retirement, but not the subsequent income evolution, was a strong predictor of IHD post-retirement. This socioeconomic gradient was partly mediated by the protective effect of neighbourhood-based social support, which may be particularly important among the elderly in compensating for social disruptions related to retirement.