Faculty, Staff and Student Publications
Publication Date
9-1-2024
Journal
European Journal of Epidemiology
Abstract
The human sex ratio at birth (SRB) undergoes temporary changes around a mean proportion of 0.51 male births. SRB has been well studied for historical, geographical, and secular trends, but until now not linked to health outcomes in the total population, e.g. for cardiovascular disease (CVD) or mortality during follow-up of birth cohorts. We used linkage analysis based on national registers in Sweden that cover all births from 1900 to 2016. SRB at birth was calculated by every 10-year birth cohort in all survivors living in 1997 for a follow-up analysis of risk of CVD and mortality with data from national registers. When the highest quartile of SRB was used as reference, a slightly increased risk of fatal CVD (HR 1.03 (95% confidence intervals, CI): 1.02-1.04), non-fatal CVD (HR 1.01; 95%CI: 1.01-1.02) and mortality (HR 1.02; 95%CI, 1.01-1.03) was found after full adjustments in men belonging to the lowest SRB quartile. A similar pattern was also found for fatal CHD in women. in the lowest SBR quartile compared to the highest, HR 1.03 (95%CI: 1.02-1.05). In conclusion, in birth cohorts with a relatively lower than expected number of males born, long-term adverse health effects were observed with slightly increased cardiovascular risk and total mortality at the population level. This could indicate that men belonging to so-called "culled cohorts" in a developed country during the 20th century are characterized by a slightly increased risk that could reflect negative early life influences and environmental exposures in pregnant women resulting in selective loss of male embryos or fetuses. In a public health perspective SRB could be of some importance to monitor as an aspect of birth statistics linked to relatively minor population health effects.
Keywords
Humans, Sweden, Cardiovascular Diseases, Male, Female, Registries, Sex Ratio, Adult, Risk Factors, Infant, Newborn, Birth Cohort, Mortality, Cause of Death, Middle Aged, Cardiovascular disease, Epidemiology, Mortality, Registers, Sex ratio at birth, Time trends
DOI
10.1007/s10654-024-01137-1
PMID
39004637
PMCID
PMC11470864
PubMedCentral® Posted Date
7-15-2024
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes