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 1 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.