Fig. 1

Principal component analysis (PCA) score plots, orthogonal projections to latent structure discriminant analysis (OPLS-DA) score plots and corresponding validation plots in ESI⁺ mode. (A) The workflow of the study. PCA score plots of all groups (B), control (n = 12) and old (n = 13) groups (C), control and DOR (n = 12) groups (F), control and scPOI (n = 14) groups (I), control and POI (n = 19) groups (L). OPLS-DA score plots of control and old groups (D), control and DOR groups (G), control and scPOI groups (J), control and POI groups (M). Permutation test of OPLS-DA model in control and old groups (E), control and DOR groups (H), control and scPOI groups (K), control and POI groups (N). Ctrl: control. DOR: diminished ovarian reserve. scPOI: subclinical premature ovarian insufficiency. POI: premature ovarian insufficiency