Causal relation of 11 trace elements, 22 dietary factors with hyperemesis gravidarum based on Mendelian randomization analysis

ObjectiveTo investigate the causal relationship between 11 trace elements(calcium,iron,zinc,selenium,magnesium,copper,vitamin A,vitamin C,vitamin D,vitamin E,carotene),22 common dietary factors(alcohol consumption,beef,bread,cereal,cheese,coffee,cooked vegetable,dried fruit,fresh fruit,lamb,non⁃oily fish,oily fish,pork,poultry,processed meat,raw vegetable,salt added to food,tea,hot drinks,carbonated beverage,garlic intake,Chinese chive) and hyperemesis gravidarum using Mendelian randomization.MethodsAll data were summarized by using Genome⁃Wide Association Studies(GWAS),with single nucleotide polymorphisms(SNPs) as instrumental variables.Analyses were performed using inverse variance weighting,weighted mode,MR Egger,and weighted median.Cochrane's Q test was used to identify heterogeneity of results.MR Egger intercept test and "leave⁃one⁃out" test were applied to evaluate the robustness of the associations between the 11 trace elements,22 dietary factors and hyperemesis gravidarum.ResultsThe results showed that vitamin D supplementation could reduce the risk of hyperemesis gravidarum[OR=0.48,95%CI(0.30,0.75)].No significant effects of the other 10 trace elements or 22 dietary factors on the risk of hyperemesis gravidarum were observed(P>0.05).There was no horizontal pleiotropy or heterogeneity(P>0.05),indicating the robustness of the results.ConclusionsVitamin D could reduce the risk of hyperemesis gravidarum.No effects of the other 10 trace elements or 22 dietary factors on increasing or decreasing the risk of hyperemesis gravidarum were found temporarily.