[Changes of plasma obestatin and ghrelin levels after soluble fiber with glucose and after fiber alone in healthy women and in patients with bulimia nervosa].

BACKGROUND

The recent identification of obestatin, a novel peptide hormone derived from the same gene as ghrelin, has added further complexity to ghrelin physiology. Despite the rapid progress, many questions remain unanswered, including the regulation of orexigen ghrelin and putative anorexigen obestatin secretion by food composition in humans. The present study was undertaken to investigate the influence of caloric and noncaloric food on plasma ghrelin and obestatin concentrations in healthy women (n = 6; age 23.83 +/- 1.1 years; BMI 20.85 +/- 0.87 kg/m2) and in bulimia nervosa patients (n = 6; age 26.6 +/- 5.2 years; BMI 19.2 +/- 1.44 kg/m2), characterized by abnormal eating behaviour and imbalance in energy homeostasis.

METHODS AND RESULTS

After overnight fasting, plasma ghrelin and obestatin were measured by commercial radioimmunoassay kits before and after consumption of soluble fiber alone or with glucose. In both groups plasma ghrelin and obestatin levels did not change after fiber alone, but decreased after fiber with glucose. During 30-90 min after ingestion we observed significant decrease (p < 0.05) of plasma ghrelin and obestatin levels after soluble fiber with glucose in healthy women and also in patients with bulimia nervosa, after then the levels of both hormones started to increase to preprandial levels.

CONCLUSIONS

We conclude that postprandial ghrelin and obestatin plasma levels decrease in relation to caloric content of the meal in healthy women and in patients with bulimia nervosa.