Endocrine Abstracts

Background: The relationship between energy balance and reproduction is U-shaped, meaning that both a negative and a positive energy balance have a detrimental effect on reproductive function. In a world increasingly burdened by the growing prevalence of obesity, we turned our attention to the negative extremity of weight, by exploring anorexia nervosa (AN) and constitutional thinness (CT) metabolic and reproductive features. Kisspeptin (kiss-1) is a relatively recently discovered neurohormone with implications in the onset of puberty, sex steroid feedback and brain sexualization. More recent data show a possible involvement of kisspeptin in the metabolic processes, with a role in regulating the homeostasis of blood glucose, insulinemia and appetite, as well as regulating fat deposits, but these still need confirmation in further studies.

Objectives: The aim of this study was to evaluate the particularities of the indicators of reproductive function and look for possible implications in this regard of the neurohormone kiss-1 in normal and underweight patients, with or without eating disorders such as AN. In particular, the study focuses on the role of kisspeptin in amenorrhea induced by dietary restriction in patients with AN.

Material and Methods: We included in this cross-sectional and observational study a cohort of 34 young female patients gathered in 4 similar-sized groups, as it follows: AN and underweight, AN and normal weight, CT, and healthy, normal weight patients. Anamnestic, anthropometric and biological data were recorded, as well as the total fat percentage (TFP) data from the whole-body DXA scan.

RESULTS: Kiss-1 was significantly higher in patients with atypical AN subjects than in underweighted, typical AN patients (1.24±0.15 vs 0.96±0.17 ng/ml, P=0.03). No significant associations were found between kiss-1 levels and clinical-biological factors of reproduction, even though kiss-1 was significantly correlated with TFP throughout the cohort (P=0.03, r=0.365). Menses are significantly associated with the diagnosis of AN (r=0.625, P<0.001), weight (r=0.448, P=0.005), TFP (r=0.457, P=0.007) as well as with gonadotropins and thyroid hormones levels (FSH r=0.353, P=0.007, LH r=0.474, P=0.005, TT3 r=0.472, P=0.006, fT4 r=0.625, P<0.01).

Conclusions: Kiss-1 increases in atypical AN patients, who, despite their psychiatric diagnosis, have a normal weight and are not in such deteriorating physical health condition, probably in an attempt to maintain viable reproductive function for as long as possible. This result, together with the correlation of this neurohormone with TFP, sheds light on the involvement of kiss-1 in both reproductive and metabolic regulation of the study population.