Acute and chronic effects of kisspeptin-54 administration on GH, prolactin and TSH secretion in healthy women.

Background: The peptide hormone kisspeptin is essential for human reproduction, acting on the hypothalamus to stimulate gonadotrophin-releasing hormone (GnRH) secretion. Kisspeptin is currently being evaluated as a novel therapeutic for women with infertility. However, some animal studies suggest that kisspeptin may also stimulate growth hormone (GH), prolactin and thyroid-stimulating hormone (TSH) secretion, with implications for its safety; no previous study has investigated whether kisspeptin stimulates these pituitary hormones in humans.

Aim: To determine whether kisspeptin-54 modulates GH, prolactin and TSH secretion in healthy women.

Design And Participants: Prospective, single-blinded, placebo-controlled, one-way crossover study. Five healthy women received 7 days of twice-daily subcutaneous bolus vehicle (month 1) or 6·4 nmol/kg kisspeptin-54 (month 2).

Measurements: Serum samples were analysed post hoc for GH, prolactin and TSH.

Results: Mean serum GH, PRL and TSH did not change during the first 4 h following kisspeptin-54 injection when compared with vehicle. The mean frequency or amplitude of GH pulses (which influence GH function) did not change acutely following kisspeptin-54 injection when compared with vehicle. No chronic changes in serum GH, PRL or TSH were observed over the 7-day period of twice-daily kisspeptin-54 injections when compared with vehicle.

Conclusion: While we cannot exclude any effect of kisspeptin-54 on GH, prolactin or TSH secretion, we observed no significant changes in these hormones at a dose of kisspeptin-54 administration known to stimulate gonadotrophin secretion in a small study of healthy women. These data have important implications for the potential of kisspeptin to treat patients with infertility.