Fig. 3

Changes in serum estrogens are associated with plasma metabolite changes in postmenopausal metformin-treated women. (a) The box plots represent changes (post-treatment vs. baseline) in serum E1 and E2 in the postmenopausal women treated with placebo or metformin in the MetBreCS trial. The negative β-regression coefficients derived from the multivariable linear model fit on these changes, adjusted for the baseline value of each steroid hormone and baseline BMI, indicate a decrease in serum E1 and E2 in the metformin arm. The p-value of the treatment covariate (Metformin vs. Placebo) from the multivariate linear model fit and the FDR-corrected p-value are indicated above the graphs. (b,c) Highly correlated plasma metabolite changes (post-treatment vs. baseline) with serum E1 and E2 changes in postmenopausal placebo- (panel B) and metformin-treated (panel C) groups. Positively and negatively correlated metabolites are represented by blue and red lines, respectively. The thickness of the lines indicates the correlation coefficient values (Spearman´s correlation coefficient > 0.5, p < 0.05).