Figure 4.

Subgroup analysis of the association between serum leptin levels and breast cancer in different menopausal status groups. Zero is not included in this confidence interval, which indicates a difference between the case and control groups. A negative SMD value suggests that the mean of the case groups is lower than that of the control groups in the premenstrual group, while the positive SMD value suggests that the mean serum leptin level in the case groups is higher than that in the control groups in the postmenstrual group.