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

Abstract

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.