Adiponectin in anorexia nervosa and bulimia nervosa

To study the role of adiponectin, a novel adipocyte-specific secreted protein, on the pathophysiology of eating disorders, circulating levels of fasting adiponectin, leptin, insulin, and glucose were measured in 31 female patients with anorexia nervosa (AN) and in 11 with bulimia nervosa. Hormone levels were compared with 16 age-matched, normal body weight controls, six healthy constitutionally thin subjects, and nine obese subjects. Moreover, changes in levels were reevaluated after nutritional treatment and weight gain in 13 patients with AN. Serum adiponectin concentrations in AN and bulimia nervosa were significantly lower than those in normal-weight controls. These results were unexpected because the levels were high in constitutionally thin subjects and low in obese subjects, which provide a negative correlation with body mass index (BMI) and body fat mass. In contrast, serum leptin levels correlated very well with BMI and fat mass among all the patients and controls. The insulin resistance was significantly low in AN and high in obese subjects. The concentrations of adiponectin after weight recovery increased to the normal level despite a relatively small increase in BMI. These findings suggest that abnormal feeding behavior in the patients with eating disorders may reduce circulating adiponectin level, and weight recovery can restore it.     

The endocrinology of anorexia nervosa and bulimia nervosa

Considerable evidence exists of hypothalamic dysfunction in patients with anorexia nervosa and bulimia nervosa. This dysfunction is reflected in disturbances of endocrine function including abnormalities of gonadotropin, growth hormone, and corticotropin-releasing hormone secretion. Whereas these disturbances are generally reversed with nutritional rehabilitation and weight restoration, it is not evident to what extent nutritional factors are the primary etiology or whether they unmask an otherwise existing but compensated central disturbance. Similarly, endocrine disturbances may be a final common pathway in which disturbances of diet, weight, activity, stress, and mood as well as hypothalamic dysfunction are expressed.     

Update on anorexia nervosa

Anorexia nervosa is an adolescent pathology of the present. Its frequency is increasing in the western countries. New data concerning the criteria of diagnosis, the evolution, the prognosis, the psychopathology and the treatment have been drawn of numerous recent studies and are exposed in the paper.     

Osteoporosis in anorexia nervosa

Anorexia nervosa (AN) has recently become one of common disorders in adolescent girls. A chronic course of AN is related to morbidity, with one of the most serious medical complications being severe osteopenia. The prevalence of osteoporosis is estimated to be 40 % in AN during the follow up. The incidence of bone fracture in AN after the recovery of body weight is reported to be two to seven higher than that in healthy age-matched controls. Because adolescence is a critical time in terms of acquisition of peak bone mass, osteopenia during this time may be permanent. Adult woman with adolescence-onset AN has lower bone mineral density than that with adult-onset AN. In addition, bone mineral density (BMD) of AN has been shown to be influenced by several factors, including reduced body weight due to malnutrition, intake of calcium and vitamin D, and duration of estrogen deficiency. Among them, body weight is known to be the most important prognostic factor, both in a short and long period of years. Thus, medical doctor should monitor BMD in patients with AN throughout their life.     

Hyperadiponectinaemia in anorexia nervosa

OBJECTIVE: Adiponectin (ApN) is a fat-derived hormone that enhances insulin sensitivity, controls body weight, prevents atherosclerosis and negatively regulates haematopoiesis and immune functions. In contrast to many proteins secreted by adipose tissue, the circulating level of ApN falls in obesity and insulin resistance states. The influence of starvation-induced depletion of fat stores on ApN concentrations is yet unknown. We therefore investigated plasma ApN in anorexia nervosa (AN). PATIENTS AND DESIGN: We measured plasma ApN in 26 female anorectic patients and examined its relationships to several anthropometric or metabolic parameters. Twenty-four age-matched healthy female controls (C) were also studied. RESULTS: Body mass index (BMI) and fat mass were markedly decreased in AN. However, plasma ApN levels were 30% higher in anorectic than in control subjects (P < 0.01), while a reverse pattern was observed for leptin concentrations. When normalized for fatness, ApN values almost doubled in AN. ApN levels were negatively correlated with BMI and fat mass (P < 0.05 in the combined population, AN + C). Insulin sensitivity tended to be 40% higher in AN (n = 7) than in C (n = 12) subjects, and plasma ApN levels were positively correlated with insulin sensitivity (P < 0.05 in AN + C subgroups). Total and low density lipoprotein (LDL)-cholesterol were higher, or tended to be higher, in AN, but there were no correlations between plasma ApN and plasma lipids. By contrast, ApN was related to the lipid profile, in a manner consistent with its antiatherogenic role, in healthy controls [i.e. negatively correlated with triglycerides, total and LDL-cholesterol and total/high density lipoprotein (HDL) cholesterol; P < 0.05 or less for each parameter]. In a multiple regression analysis, BMI and insulin sensitivity in AN were independent determinants for ApN levels, explaining up to approximately 80% of the variance in this measure. CONCLUSIONS: Plasma adiponectin levels are increased in anorexia nervosa. This may, at least in part, be due to the lack of negative feedback exerted by fat mass on adiponectin production and/or to enhanced insulin sensitivity. We speculate that hyperadiponectinaemia could, in turn, contribute to maintain a state of enhanced insulin sensitivity and possibly exacerbate haematological and infectious complications of anorexia nervosa.     

Gastric emptying in patients with bulimia nervosa and anorexia nervosa

A dual radioisotope technique was used to measure gastric emptying of a mixed liquid and solid meal in 11 patients with bulimia nervosa, and was compared with 10 patients with anorexia nervosa and a sex-matched control population. The relationship of body weight and gastrointestinal symptoms to gastric emptying was also examined. Gastric emptying of solids in patients with bulimia nervosa was similar to that in controls (gastric T1/2 131 +/- 15 min vs 119 +/- 7 min; mean +/- SEM). In contrast, patients with anorexia nervosa had overall delayed emptying (182 +/- 31 min; p less than 0.05); six patients had normal emptying of the solid components of the meal and four had markedly delayed emptying. Gastric emptying of liquids was similar in the bulimics and controls (gastric T1/2 48 +/- 5 min and 49 +/- 4 min, respectively), whereas the anorexics tended to have prolonged gastric emptying (65 +/- 11 min, p = NS). There was no correlation between body weight, gastrointestinal symptoms, and gastric emptying in either group. These findings suggest that gastrointestinal symptoms are unreliable indicators of gastric emptying in patients with eating disorders, and that gastric emptying studies should be performed in such patients before treatment with prokinetic agents is considered.