Figure 1.

Average estradiol (dotted line), progesterone (solid line) and leptin (dashed line) concentrations across a standardized menstrual cycle for 467 ovulatory (A) and 42 anovulatory cycles (B), after adjustment for differences in percent body fat and age.

*Leptin was significantly lower in anovulatory cycles compared with ovulatory cycles (p<0.05). Geometric means were estimated and p-value was assessed using linear mixed models adjusted for percent body fat and age.

^a Leptin during menses, middle follicular and late follicular phases, respectively, were lower compared to all subsequent phases and leptin at the time of the LH surge was higher than all subsequent phases except the mid luteal phase (p <0.05). P-values were assessed using linear mixed models.

^b Expected menstrual cycle phases for anovulatory cycles were determined based on fertility monitor readings and each participant’s self-reported typical menstrual cycle length. Mean cycle day of blood collection was as follows: menses (2.6), middle follicular (7.8), late follicular (13.8), LH surge (15.9), ovulation (18.1), early luteal (20.6), mid-luteal (23.4), and late luteal (26.1). Leptin at the time of the expected LH surge was higher than at the time of expected ovulation and the late luteal phase, and leptin during the expected early luteal phase was higher than at the expected late luteal phase (p<0.05). P-values were assessed using linear mixed models.