Circulating leptin levels during ovulation induction: relation to adiposity and ovarian morphology

Objective: To assess serum leptin levels based on body habitus and ovarian morphology during controlled ovarian hyperstimulation. Design: Prospective analysis. Setting: University IVF program. Patient(s): Women undergoing IVF-ET were divided into two groups, obese ovulatory women (n = 6; mean (±SD) body mass index, 30.1 ± 0.6 kg/m 2) and lean ovulatory women (n = 20); mean (± SD) body mass index 22.0 ± 0.2 kg/m 2). Lean women were categorized further according to whether they had polycystic-appearing ovaries (n = 8) or normal-appearing ovaries (n = 12). Intervention(s): Controlled ovarian hyperstimulation and IVF. Main Outcome Measure(s): Serum estradiol, testosterone, and leptin. Result(s): Mean (± SD) leptin levels were significantly higher before and after GnRH agonist down-regulation in obese women (41.7 ± 5.2 pg/mL and 36.1 ± 5.8 pg/mL, respectively) compared with lean women (8.4 ± 1.0 pg/mL and 6.9 ± 1.1 pg/mL, respectively). Mean (± SD) leptin levels increased significantly in both groups (54.5 ± 5.1 pg/mL and 11.7 ± 1.2 pg/mL, respectively), and the mean (±SD) percentage increase was similar (55% ± 18% and 54.8% ± 17%, respectively). Mean (±SD) leptin levels were similar in women with polycystic-appearing and normal-appearing ovaries before controlled ovarian hyperstimulation, but increased significantly in women with polycystic-appearing ovaries afterward (14.7 ± 1.8 pg/mL and 9.3 ± 1.0 pg/mL, respectively). Conclusion(s): Significant increases in leptin levels occur during controlled ovarian hyperstimulation, suggesting that leptin plays a role in follicular growth and maturation. The exaggerated response in women with polycystic-appearing ovaries reflects either a greater number of recruited follicles or a predisposition of adipocytes to leptin production.