Childhood obesity and hypertension in pregnancy: a two-sample Mendelian randomization analysis

BACKGROUND: The causal relationship between childhood obesity and hypertension in pregnancy remains unclear. To examine the causal association between childhood obesity and hypertension in pregnancy, two-sample Mendelian randomization analysis was applied. METHODS: Single-nucleotide polymorphisms (SNPs) associated with childhood obesity were obtained from a published genome-wide association study (GWAS) of 13 848 European individuals. Summary-level data for hypertension in pregnancy were obtained from the FinnGen consortium (11534 cases and 162212 controls). Inverse-variance weighted analysis, weighted-median analysis, and Mendelian randomization-Egger regression were conducted in this Mendelian randomization analysis. Sensitivity analyses were conducted to confirm the accuracy and robustness of our results. RESULTS: Genetically determined childhood obesity significantly affects hypertension in pregnancy by IVW [odds ratio (OR) = 1.161, 95% confidence interval (CI) 1.086–1.039; P = 9.92 × 10(−6)] and weighted median (OR = 1.123, 95% CI 1.038–1.214; P = 0.004). These results were validated by multiple sensitivity analyses. CONCLUSION: A causal effect between genetically predicted childhood obesity and the risk of hypertension in pregnancy was identified. The prevention of hypertension in pregnancy should be promoted in populations with childhood obesity.