ECE2024 Oral Communications Oral Communications 9: Pituitary and Neuroendocrinology | Part II (6 abstracts)
1Imperial College London, Section of Endocrinology and Investigative Medicine, London, United Kingdom; 2Imperial College Healthcare NHS Trust, Department of Endocrinology, London, United Kingdom; 3Invicro London, London, United Kingdom; 4Imperial College Healthcare NHS Trust, Jane Wadsworth Sexual Function Clinic, London, United Kingdom
Background: The neuropeptide kisspeptin is a key endogenous activator of the reproductive system. Due to its crucial role in modulating reproductive and behavioural processes, there has been accelerating interest in targeting kisspeptin-pathways to treat reproductive and psychosexual disorders. However, contradictory pre-clinical data from animal models suggests that kisspeptin can have an anxiolytic, anxiogenic or have no effects on anxiety. Given the rapid development of kisspeptin-based therapeutics, it is imperative to elucidate kisspeptins effects on anxiety in humans. Herein, we report the largest study investigating the effects of kisspeptin on psychometric measures of anxiety and circulating cortisol levels.
Methods: Ninety-three eugonadal participants (n=29 healthy men, n=32 men with low sexual desire, n=32 women with low sexual desire) completed a double-blind, randomised, placebo-controlled, crossover study. Participants attended twice: once for intravenous infusion of kisspeptin-54 (1 nmol/kg/h) over 75 mins and for rate-matched placebo. Blood was sampled at 15 min intervals from -30 to 75 mins to measure circulating kisspeptin, LH, testosterone and cortisol [in men] and oestradiol [in women]. The validated State-Trait Anxiety Inventory (STAI) Y2-Trait was completed prior to infusions to exclude abnormal anxiety traits, with all scores within normal limits. Subsequently, participants completed the STAI Y1-State before and at the end of the infusions to assess for any dynamic effects on anxiety.
Results: Ninety-three participants (mean age±SD 30.9±8.7 yrs, BMI 24.0±3.7 kg/m2) completed the study. Baseline state anxiety and circulating cortisol levels were equivalent at the beginning of the kisspeptin and placebo visits. Intravenous kisspeptin potently increased serum LH to levels previously described using this administration protocol, confirming that the dose was biologically active (P>0.001). Importantly, state anxiety was unaltered by kisspeptin, compared to placebo (mean difference in STAI Y1-State scores during the infusions: kisspeptin -0.03±8.11, placebo 0.77±8.08, P=0.43). Furthermore, kisspeptin had no effect on circulating cortisol compared to placebo during the 75 min study period (P=0.92). As expected, kisspeptin had no significant effects on downstream sex-steroid levels during the 75 min study period, thereby removing these as possible confounders.
Discussion: This is the largest study demonstrating that a biologically active dose of kisspeptin to healthy participants and patients with psychosexual disorders does not affect psychometric measures of anxiety and associated circulating cortisol levels. Given that animal studies have yielded inconsistent results, this provides key clinical data and reassurance that kisspeptin administration in humans does not induce anxiety and so informs safety for the rapid development of kisspeptin-based therapeutics for reproductive and psychosexual disorders.