Insulinogenic index at 15 min as a marker of stable eating behavior in bulimia nervosa.

BACKGROUND & AIMS: The aim of this study was to determine the relationship between insulinogenic index at 15 min (II15 min), body weight maintenance, and the presence of vomiting in patients with bulimia nervosa. METHODS: Forty-eight bulimic inpatients and 14 controls underwent an oral glucose tolerance test on the seventh hospital day. We calculated II15 min and other biological markers, including serum amylase concentrations. During the first week after admission, we monitored the frequency of vomiting and calculated changes in body weight. Patients were divided into 4 subgroups according to the presence of vomiting and weight loss. RESULTS: Two-factor analysis of variance of the II15 min value revealed significant main effects of vomiting and body weight change (P < 0.001 for both). The II15 min values for controls and bulimic patients with weight loss and no vomiting were lower than those of other bulimic groups. The II15 min values were positively correlated with serum amylase concentrations (r = 0.37, P < 0.01), body weight change (r = 0.35, P < 0.05), and frequencies of vomiting (r = 0.49, P < 0.05). CONCLUSIONS: These findings suggest that II15 min values may be a useful marker for assessing the stability of eating behavior in patients with bulimia nervosa.

Eating pattern and the effect of oral glucose on ghrelin and insulin secretion in patients with anorexia nervosa.

OBJECTIVE: Ghrelin is thought to be involved in the regulation of eating behaviour and energy metabolism in acute and chronic feeding states. Circulating plasma ghrelin levels in healthy humans have been found to decrease significantly after oral glucose administration. Because it is suggested that eating behaviour may influence the secretion of ghrelin and insulin in anorexia nervosa (AN), we examined the effect of oral glucose on ghrelin and insulin secretion in subtypes of AN patients. DESIGN AND PATIENTS: Twenty female AN patients and 10 age-matched female controls were subjects. The patients were subdivided into two subtypes based on eating behaviour as follows: 11 restricting type (AN-R), nine binge-eating and purging type (AN-BP). Subjects underwent an oral glucose tolerance test at 08.00 h. Blood was collected 0, 30, 60, 120 and 180 min after the glucose load. RESULTS: Both AN-R and AN-BP had a significant increased basal ghrelin level (P < 0.01) and a significantly decreased basal insulin level (P < 0.05) as compared to controls. The time of the nadir of mean ghrelin in AN-BP (120 min, 58.1% of basal level, 204.9 +/- 34.3 pmol/l, mean +/- SEM) was delayed compared to controls (60 min, 60.2%, 74.3 +/- 7.9 pmol/l), and in the AN-R group it kept decreasing for 180 min (80.0%, 182.4 +/- 31.5 pmol/l). The peaks insulin levels in AN-BP (120 min, 319.3 +/- 88.8 pmol/l) and AN-R (180 min, 418.9 +/- 68.4 pmol/l) were also delayed as compared to controls (60 min, 509.2 +/- 88.8 pmol/l). The glucose level at 180 min in AN-R was significantly (P < 0.05) higher than in controls. CONCLUSIONS: These findings suggest that differences in eating behaviour in AN may induce alterations in both ghrelin and insulin metabolism in the acute feeding state. Furthermore, metabolic changes in the restrictive eating pattern may be related to the pathophysiology of small quantitative meal intake in AN-R patients.

Fasting plasma ghrelin levels in subtypes of anorexia nervosa.

Ghrelin has a role in regulating eating behavior and energy metabolism in the central nervous system, and has been reported to play an important role in the pathophysiology of anorexia nervosa (AN). The aim of the present study was to compare fasting plasma ghrelin levels in different subtypes of untreated AN patients. The subjects included 39 female AN patients and 11 female controls. The patients were then divided into two subtypes as follows: 19 AN patients with restricting (AN-R) and 20 AN patients with binge-eating/purging (AN-BP) form of the illness. Blood samples from subjects after an overnight fast were used to analyze plasma ghrelin concentrations. Plasma ghrelin concentrations in both AN-R and AN-BP were negatively correlated with body mass index (BMI). The mean plasma ghrelin levels in both AN-R and AN-BP were significantly higher than that in controls. The mean ghrelin level in AN-BP was significantly higher than that in AN-R. However, mean BMI and serum potassium in both groups were not significantly different. These results suggest that both BMI and the presence of binge-eating/purging may have some influence on fasting plasma ghrelin levels in patients with AN.