Serum kisspeptin concentrations are negatively correlated with body mass index in adolescents with anorexia nervosa and amenorrhea.

OBJECTIVE To measure, for the first time, serum kisspeptin concentrations in adolescent females with anorexia nervosa (AN) and associated amenorrhea, and investigate potential correlations of kisspeptin with anthropometric, bone and hormonal data. DESIGN Setting: University Adolescent Medicine Center. PARTICIPANTS Females aged 12-20 years with typical or atypical AN (based on DSM-5 diagnostic criteria) and controls. INTERVENTIONS Measurement of body mass index (BMI), whole body/lumbar spine bone mineral density and serum concentrations of kisspeptin, follicle stimulating hormone, luteinizing hormone (LH), prolactin (PRL), thyroid stimulating hormone (TSH), free thyroxine, triiodothyronine, estradiol (E2), 17-hydroxyprogesterone. MAIN OUTCOME MEASURES Kisspeptin serum concentrations and correlations between kisspeptin and AN-related anthropometric, bone and hormonal changes. RESULTS Participants included 37 females, 22 with AN (typical AN group=17, atypical AN group=5) and 15 in the control group. All typical AN patients had secondary amenorrhea. Wide inter-subject variation (101.9-709.1 ng/L) in kisspeptin levels was observed with no significant differences among study groups; there was a trend toward higher concentrations in the atypical AN group. Adolescents with typical AN had significantly lower BMI (P<0.001), lumbar spine z-score (P=0.016), serum E2 (P<0.001), LH (P=0.016), PRL (P=0.034) and TSH (P=0.045) than controls. They also had lower BMI (P=0.009) and TSH (P=0.027) than girls with atypical AN. An inverse correlation between BMI and serum kisspeptin was noted in the typical AN group (r=-0.60, P=0.012). CONCLUSIONS Serum kisspeptin concentrations overlapped between patients and controls; in typical anorexic adolescents kisspeptin concentrations were negatively correlated with BMI. Future studies are needed to explore kisspeptin physiology in AN.