Abstract
CONTEXT: The hormone kisspeptin has crucial and well-characterized roles in reproduction. Emerging data from animal models also suggest that kisspeptin has important metabolic effects including modulation of food intake. However, to date there have been no studies exploring the effects of kisspeptin on brain responses to food stimuli in humans. OBJECTIVE: This work aims to investigate the effects of kisspeptin administration on brain responses to visual food stimuli and psychometric parameters of appetite, in healthy men. DESIGN: A double-blinded, randomized, placebo-controlled, crossover study was conducted. PARTICIPANTS: Participants included 27 healthy, right-handed, eugonadal men (mean ± SEM: age 26.5 ± 1.1 years; body mass index 23.9 ± 0.4 kg/m2). INTERVENTION: Participants received an intravenous infusion of 1 nmol/kg/h of kisspeptin or rate-matched vehicle over 75 minutes. MAIN OUTCOME MEASURES: Measurements included change in brain activity on functional magnetic resonance imaging in response to visual food stimuli and change in psychometric parameters of appetite, during kisspeptin administration compared to vehicle. RESULTS: Kisspeptin administration at a bioactive dose did not affect brain responses to visual food stimuli or psychometric parameters of appetite compared to vehicle. CONCLUSIONS: This is the first study in humans investigating the effects of kisspeptin on brain regions regulating appetite and demonstrates that peripheral administration of kisspeptin does not alter brain responses to visual food stimuli or psychometric parameters of appetite in healthy men. These data provide key translational insights to further our understanding of the interaction between reproduction and metabolism.