Causal relationship association of cheese intake with gestational hypertension and diabetes result from a Mendelian randomization study

BACKGROUND: The evidence from observational studies has been inconclusive on the causal relationship between cheese intake and gestational hypertension or diabetes. AIM: To determine whether cheese consumption was causally related to hypertension and diabetes during pregnancy. METHODS: This was a two-sample Mendelian randomized (MR) study. Summary-level genetic data for cheese intake was exposure and corresponding outcome data for gestational hypertension and gestational diabetes were extracted from the IEU OpenGWAS database. MR analysis was conducted using inverse variance weighting. For sensitivity analyses, MR-Egger regression, weighted median, weighted mode, and leave-one-out methods were conducted. A fixed-effect model was used to meta-analyze two sample MR estimates. The traits of gestational hypertension were pregnancy hypertension (123579 individuals) and oedema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium (123579 individuals), and traits of gestational diabetes were gestational diabetes (123579 individuals) and diabetes mellitus in pregnancy (116363 individuals), respectively. RESULTS: Cheese intake per standard deviation increase has causally reduced the risks of gestational hypertension [odds ratio (OR) = 0.60, 95% confidence interval (CI): 0.47-0.76, P < 0.001] and gestational diabetes (OR = 0.41, 95%CI: 0.30-0.55, P < 0.001) in inverse variance weighted analysis. Sensitivity analysis showed no heterogeneity (all P > 0.05) nor horizontal pleiotropy (all P > 0.05) in the relationship between cheese intake and gestational hypertension, but heterogeneity presented (all P < 0.05) in relation to gestational diabetes in the two-sample MR analysis. CONCLUSION: Cheese intake was inversely associated with gestational hypertension and gestational diabetes in MR analysis, suggesting that cheese consumption may be beneficial in preventing hypertension and diabetes during pregnancy.