Ghrelin levels in obesity and anorexia nervosa: Effect of weight reduction or recuperation

Objective To study the influence of dietary intervention on plasma ghrelin levels in obese children and adolescents with anorexia nervosa (AN). Study design Prepubertal obese children (n = 16) and 16 anorexic adolescents were studied at three different points: clinical diagnosis and after a reduction or recuperation of 25% and 50% of the initial BMI SD score. Controls included 21 Tanner growth stage I and 36 Tanner growth stage 5 subjects. We analyzed plasma ghrelin levels and their correlation with plasma levels of leptin, insulin, insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 1 (IGFBP-1), insulin-like growth factor binding protein 2 (IGFBP-2), insulin-like growth factor binding protein 3 (IGFBP-3), and integrated concentration of growth hormone (ICGH) before and after dietary intervention. Results At diagnosis, ghrelin levels were significantly decreased in obese children (52% of control levels) and significantly increased in adolescents with AN (164% of control levels). After dietary intervention, ghrelin increased in obese patients but without reaching control levels even after a 50% reduction in body mass index (BMI). In adolescents with AN, ghrelin levels normalized after a 25% increase in BMI. Ghrelin correlated negatively with the BMI and positively with IGFBP-1 levels in controls but not in obese patients or in patients with AN at diagnosis. The positive correlation between ghrelin and IGFBP-1 was recovered after dietary intervention. Conclusions Plasma ghrelin levels present opposite changes in obesity and AN after dietary intervention, suggesting that ghrelin is a good marker of nutritional status.