How far are socioeconomic differences in coronary heart disease hospitalization, all-cause mortality and cardiovascular mortality among adult Swedish males attributable to negative childhood circumstances and behaviour in adolescence?

OBJECTIVES: Coronary heart disease (CHD) and mortality are unevenly distributed between social classes, the lower being disadvantaged compared with the higher. Adverse social circumstances in childhood have been related to an increased risk of CHD and mortality in adulthood. The present purpose was to investigate the effect of differences in social disadvantage in early life on later differences in risk of CHD, all-cause mortality, and cardiovascular mortality between socioeconomic groups among Swedish men aged 40-50.
METHODS: Data on circumstances in childhood and adolescence, e.g. crowded housing and low social position of the father, measured at age 9-11, was collected among 49,323 men, born in 1949-51, and conscripted for compulsory military training in 1969/70. Data on adult socioeconomic position was obtained from the 1990 census, data on CHD from the Swedish In-patient Care register 1991-2000, and data on mortality from the Causes of Death register 1991-2000.
RESULTS: A social gradient was found for all health outcomes. The relative risk of CHD, all-cause mortality, and cardiovascular mortality among unskilled workers compared with that among high-level non-manual employees was 1.82 (95% CI: 1.36, 2.44), 2.24 (95% CI: 1.72, 2.93), and 2.38 (95% CI: 1.47, 3.86) respectively. The early life risk indicators, such as crowded housing and low childhood social position (measured at age 9-11), short stature (measured at age 18-20), and low education (reported at age 18-20), were more common among those who in 1990 (i.e. at age 39-41) were manual workers than among those who were in non-manual occupations. In multivariate analyses, considering the indicators of childhood social disadvantage and adjusting for lifestyle factors established at age 18-20, (smoking, alcohol consumption, overweight) the increased relative risk of CHD hospitalization and cardiovascular mortality in the four categories of employed workers was reduced by 72-100%.
CONCLUSION: Predictors of CHD measured in childhood and adolescence may explain a substantial part of the social gradient in CHD, cardiovascular mortality, and all-cause mortality among the 40-50 year old males studied.