Observational analyses
The observational analyses were performed using R software. We firstly
used T-test to estimate the differences in age, BMI, and HGS between
male and female in the study population. Then regression analyses was
performed to evaluate the associations between C-section and left HGS
(n=160,635) and right HGS (n=160,651), respectively. Age, sex, BMI and
10 population structure principal components (PCs, calculated by UK
Biobank) were used as covariates.