The contribution of parental and grandparental childhood social disadvantage to circulatory disease diagnosis in young Swedish men

Men born out of wedlock in early twentieth century Sweden who never married have previously been shown to have a doubled mortality risk from ischaemic heart disease compared to the corresponding group of men born to married parents. This study further explores the question of childhood social disadvantage and its long-term consequences for cardiovascular health by examining the two subsequent generations. The question posed is whether the sons and grandsons of men and women born out of wedlock in early twentieth century Sweden have an increased risk of circulatory disease compared with the corresponding descendants of those born inside marriage. We examined this by use of military conscription data. The material used is the Uppsala Birth Cohort Multigenerational database consisting of individuals born at Uppsala University Hospital between 1915 and 1929 (UG1), their children (UG2) and grandchildren (UG3). Conscription data were available for UG2s born between 1950 and 1982 (n = 5,231) and UG3s born between 1953 and 1985 (n = 10,074) corresponding to 72.1% and 73.6%, respectively, of all males born in each time-period. Logistic regression showed that significant excess risk of circulatory disease diagnoses was present only among descendants of men born outside marriage, with sons and grandsons demonstrating odds ratios of 1.64 and 1.83, respectively, when BMI and height at the time of conscription, fatherʹs social class in mid-life and fatherʹs or grandfatherʹs history of circulatory disease had been adjusted for. Separate analyses showed that the effect of the maternal and paternal grandfather was of approximately the same magnitude. Further analyses revealed an interaction between the fatherʹs social class and the grandfatherʹs legitimacy status at birth on UG3-menʹs likelihood of having a circulatory disease, with elevated odds only among those whose fathers were either manual workers or self-employed. The results of this study suggest that social disadvantage in one generation can be linked to health disadvantage in the subsequent two generations.