Fig. 5: The association between thyroid-related traits and maternal blood glucose and blood pressure traits during pregnancy.

A Observational analysis. In each grid, the upper left triangle shows the regression coefficients for the phenotypic associations in the Longgang cohort, while the lower right triangle shows those for the Baoan cohort. To facilitate the comparison of effect estimates corresponding to different traits, we converted the absolute values of the estimates of phenotypic associations into Q-quantiles for plotting. We completed the analysis of phenotypic associations between gestational phenotypes and thyroid traits using generalized linear model (glm function in R 4.3.2). Black color of triangle indicates that the result is not available(due to insufficient sample size). B Bidirectional mendelian randomization, the upper left triangle of each grid indicates the results of forward MR (thyroid traits as exposure variables), while the lower right triangle indicates reverse MR (thyroid traits as outcome variables). A, B, if there is a significant difference (P < 0.05) between the effect estimates and 0, the middle of the triangle is labeled with a red asterisk (P < 0.05 and P > 0.05/14) or two red asterisks (P < 0.05/14). C The forest plot of MR results under 3 scenarios between TSH and 5 blood glucose and blood pressure trait. The MR results for three scenarios are shown: (1) Meta-Meta: the two-sample MR method is conducted in one-sample setting; (2) Baoan-Longgang: Baoan Study served as the source of exposed GWAS data, while the Longgang Study provided the outcome population. (3) Longgang-Baoan: Longgang Study served as the source of exposed GWAS data, while the Baoan Study provided the outcome population. Shown in column 4 of the figure are effect sizes (beta) of the MR results estimated using the inverse-variance weighted using multiplicative random effects approach (Method), and the error bars represent 95% confidence intervals. The squares in the middle of the lines are labeled red when there is a significant difference between the effect size and 0, and black otherwise. Abbreviation: TSH TSH levels within reference range during pregnancy, FT4 FT4 levels within reference range during pregnancy, SHO subclinical hypothyroidism during pregnancy, ISH isolated hypothyroxinemia during pregnancy, OHP overt hyperthyroidism during pregnancy, SHP subclinical hyperthyroidism during pregnancy, TPOAb TPOAb levels, Tb(+) TPOAb positivity during pregnancy and EUTb(+) TPOAb positivity with normal functioning thyroid (i.e., euthyroid). SBP systolic blood pressure, DBP diastolic blood pressure, HBA1c, glycated hemoglobin, FPG Fasting plasma glucose, OGTT0H oral glucose tolerance test 0 hour, OGTT1H oral glucose tolerance test 1 hour; OGTT2H oral glucose tolerance test 2 hour, GDM gestational diabetes mellitus.