Beyond Barker: Infant Mortality at Birth and Ischaemic Heart Disease in Older Age

Abstract
In one of the first papers on the impact of early life conditions for individuals' health in older age, Barker and Osmond (1986) show a strong positive relationship between infant mortality rates in the 1920s and ischaemic heart disease in the 1970s. We merge historical data on infant mortality rates to 370,000 individual records in the UK Biobank using information on local area and year of birth. We then go `beyond Barker’, first by showing that the relationship holds when including local geographic area fixed effects, but not when we exploit family data and compare siblings. Second, we report considerable genetic heterogeneity that is robust to within-area as well as within-family analyses. Our findings show that, in areas with the lowest infant mortality rates, the effect of one’s genetic predisposition effectively vanishes. These findings suggests that advantageous environments can cushion one's genetic disease risk.