Dexamethasone suppression test in bulimia

Bulimia and major affective disorder: experience with 105 patients

Several lines of evidence suggest that bulimia - the syndrome of compulsive binge-eating - may be related to major affective disorder. First, high rates of major affective disorder have been found both among bulimic patients and their relatives. Second, neuroendocrine abnormalities, similar to those found in major affective disorder, have been reported in bulimia. Finally, several antidepressant medications have been shown to be effective in the treatment of bulimia.

To investigate further the relationship between bulimia and major affective disorder, we evaluated 105 consecutive patients (101 women, 4 men), meeting DSM III criteria for bulimia, referred to our center, for the following: (1) rates of current or past major affective disorder and other psychiatric disorders, by DSM III criteria, using the NIMH Diagnostic Interview Schedule (n = 105); (2) family history of psychiatric disorders among first-degree relatives, by DSM III criteria (n = 101); (3) response to the 1 mg oral overnight dexamethasone suppression test (DST) with postdexamethasone plasma cortisol level measured at 16 00 h (n = 43); and (4) response to open trials of antidepressant medications, front several different classes - particularly tricyclic antidepressants, monoamine oxidase (MAO) inhibitors, and trazodone (n = 50).

The results of these studies were as follows: (1) the bulimic patients displayed a 77% lifetime prevalence rate of major affective disorder by DSM III criteria; (2) the morbid risk for major affective disorder among the firstdegree relatives of the bulimic probands was 0.29, similar to the 0.19 morbid risk found among the first-degree relatives of 40 probands with bipolar disorder, but significantly higher than the 0.03 morbid risk found among the first-degree relatives of 46 schizophrenic probands (P<0.001); (3) the bulimic patients showed a 40% rate of nonsuppression to the DST (16 00 h postdexamethasone plasma cortisol Level≥5.0 mcg/dl), significantly higher than the 9% rate of nonsuppression found among 22 normal control subjects (P<0.02); and (4) after one or more trials of antidepressant medications, 38% of the bulimic patients achieved a remission of symptoms (cessation of bingeeating episodes), 34% achieved a marked response (75-99% reduction in the frequency of binge-eating episodes), 16% achieved a moderate response (50-74% reduction in the frequency of binge-eating episodes), and 12% had no response (less than a 50% reduction in the frequency of binge-eating episodes).

Thus, on each of the four indices evaluated, patients with bulimia were similar to patients with major affective disorder, but were distinguishable from patients with other psychiatric disorders and from normal Controls. These results are consistent with the hypothesis that bulimia may be closely related to major affective disorder.

Are young women in Japan at high risk for eating disorders?: Decreased BMI in young females from 1960 to 1995

The height, weight and body mass index (BMI) of Japanese males and females aged from 6 to 24 years between 1960 and 1995 were studied. From 1960 to 1995 in males of all ages and in females aged 6-14 years height, weight and BMI increased. In females aged 15-24 years, the height increased and the weight slightly increased, but the BMI gradually decreased from 21.5 in 1960 to 20.5 in 1995. Over the last 35 years adolescent and young adult women have become thinner. Dieting to be slim has become much more prevalent among young women. These findings suggest that young females in Japan have decreased their BMI by dieting in order to become slim. If this tendency persists, with regard to a close relationship between restrained eating or dieting and eating disorders, Japanese young women have a much greater risk of developing eating disorders.

Disturbances in the hypothalamo-pituitary-adrenal and other neuroendocrine axes in bulimia

Disturbances in the hypothalamo-pituitary-adrenal (HPA) and other endocrine axes were assessed in 24 women with bulimia and healthy controls. Overnight blood samples for measuring nocturnal plasma cortisol, prolactin (PRL), growth hormone (GH), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were obtained at 30-min intervals. A 1.5 mg dexamethasone suppression test (DST) and a TRH-test were performed. Patients were monitored closely while their nutritional intake was recorded over 21 days. Compared with healthy controls, nocturnal cortisol plasma levels were not elevated in the bulimics. There was a trend toward insufficient cortisol suppression in the DST in patients with bulimia, which was most pronounced in patients with signs of restricted caloric intake. Plasma dexamethasone levels were significantly reduced in bulimics compared with healthy controls. There was a trend for blunted thyrotropin stimulating hormone (TSH) responses to thyrotropin releasing hormone (TRH) in bulimia. The prolactin response to TRH was significantly reduced in bulimics with a history of anorexia nervosa. Plasma LH and plasma FSH were significantly reduced in bulimics with signs of reduced caloric intake [low T3, high levels of beta-hydroxy-butyric acid (BHBA), reduced daily caloric intake, high number of fasting days] as compared with healthy controls. Bulimics with high BHBA levels had significantly reduced nocturnal prolactin plasma levels. Results show that multiple neuroendocrine disturbances exist in bulimia in a milder form than in anorexia nervosa. Evidence for the impact of caloric intake on endocrine functions is presented. Endocrine dysfunctions in our bulimic sample did not show a positive association with the presence of depressive symptoms.

Dexamethasone suppression test in positive and negative schizophrenia

Fifty-four inpatients with a DSM-III diagnosis of schizophrenia were studied. Patients were divided into positive and negative subtypes of schizophrenia according to Andreasen's criteria. Blood samples were obtained from all patients for 2 consecutive days to determine plasma cortisol concentrations before and after a single administration (1 mg, p.o.) of dexamethasone at 11 p.m. The results revealed a significant increase in plasma cortisol levels in schizophrenic patients, with 40% of the patients being nonsuppressors on the dexamethasone suppression test. A higher percentage (62.5%) of patients with the negative form of schizophrenia were nonsuppressors.

The DST and TRH test in bulimia nervosa

Abnormal neuroendocrine responses have been found in depression and eating disorders. It remains unclear whether these reflect an underlying shared biology or epiphenomena. To evaluate this further, we conducted the 1 mg DST and the TSH response to 500 micrograms i.v. TRH in normal-weight bulimics and controls. Bulimics (n = 18) demonstrated significantly more DST non-suppression (45%) than controls (18%; n = 20). In the bulimic group, non-suppressors were significantly thinner than suppressors, but did not differ from them on any measure of depression. Bulimics (n = 19) and controls (n = 12) responded similarly without blunting on the TSH response to TRH. These data suggest that DST non-suppression may be related to non-specific variables such as weight. Bulimics do not demonstrate TSH blunting as found in some depressed patients. These tests do not support evidence for a biological link between these disorders.

Neuroendocrine profile in bulimia nervosa

The neuroendocrinology of bulimia nervosa has only recently been investigated, with initial research suggesting some biological overlap with both anorexia nervosa (AN) and depression. Similarities among AN, depression, and bulimia include a nonsuppressed Dexamethasone Suppression Test and an abnormal growth hormone (GH) response to thyrotropin-releasing hormone (TRH). Bulimics and anorectics both tend to have a delayed thyrotropin (TSH) response to TRH and elevated basal GH levels. Bulimics, however, have a normal GH response to clonidine, a nonblunted TSH response to TRH, low basal prolactin (PRL) levels, and may have an exaggerated PRL response to TRH. Unpublished data suggest bulimics may have a gonadotropin profile distinct from either AN or depression, as well as a variety of other endocrinopathies. Although many of these abnormalities may reflect malnutrition despite normal weight, other factors that are as yet unidentified are likely to be contributing to the neuroendocrine abnormalities seen in bulimia.

Prevalence of binge-eating and bulimia among adolescent women in Japan

This study examined by questionnaire the prevalence of binge-eating and bulimia among 220 women at a school of nursing and 236 women at a junior college, all from 18 to 21 years old, in two different areas of Japan. Binge-eating more than once a week was found in 14 (6.5%) of the nursing school students and 21 (9.1%) of the college women. Self-induced vomiting and use of purgatives were found in 19 (8.7%) and 12 (5.5%) of the nursing school students, and 19 (8.1%) and 9 (3.8%) of the college women, respectively. The difference between these two groups was not significant. The prevalence of binge-eating more than once a week, together with self-induced vomiting or purgative use, was 3.6% in the nursing school students, 2.1% in the college women, and 2.9% in the total sample. These women appeared to meet both DSM-III criteria for bulimia and Russell's criteria for bulimia nervosa.

The dexamethasone suppression test in bulimia nervosa

In a study of the dexamethasone suppression test (DST) in patients with bulimia nervosa, a non-suppression rate of about 50% was found. The only clinical correlates of DST non-suppression were a previous history of weight loss and/or of anorexia nervosa. These results suggest that DST non-suppression in these subjects may be a trait rather than a state marker of anorexia nervosa.

The dexamethasone suppression test for Japanese with eating disorders

A one-mg oral overnight dexamethasone suppression test (DST) was conducted on 22 inpatients with eating disorders. To confirm that the dexamethasone tablets had been ingested, we measured the plasma concentrations of dexamethasone the next morning (at 0900 hr after DST). The diagnosis of anorexia nervosa and bulimia was made according to the criteria for DSM-III, respectively. Of the 22 patients with eating disorders, 16 satisfied the criteria for anorexia nervosa and 6 for bulimia. The DST was carried out within 2 weeks of hospitalization on each patient. The subjects were given 1 mg of dexamethasone in the evening (at 2300 hr) and blood samples were collected the following day (at 0900, 1600 and 2100 hr, respectively). The plasma cortisol and dexamethasone levels were concurrently determined by RIA. The criterion for non-suppression was a failure to suppress the plasma cortisol levels below 5.0 micrograms/dl in any one of the three samples. All but one patient with bulimia had ingested the dexamethasone. Thirteen (62%) of 21 patients with eating disorders were nonsuppressors. We found a significant positive correlation between the plasma cortisol levels at 1600 hr or 2100 hr and a decrease in ideal body weight (n = 16, r = 0.613, p less than 0.05; r = 0.75, p less than 0.01, respectively) and a significant inverse relationship between the plasma dexamethasone levels at 0900 hr and the plasma cortisol levels at 1600 hr was recognized (n = 21, r = 0.631, p less than 0.01). These results suggest that the blood dexamethasone levels as well as body weight might contribute to the abnormalities of DST seen in patients with eating disorders.

Thyrotropin, prolactin, and growth hormone responses to thyrotropin-releasing hormone in anorexia nervosa and bulimia

Serum thyrotropin (TSH), prolactin (PRL), and growth hormone (GH) levels were measured before and after stimulation with thyrotropin-releasing hormone (TRH) in 10 patients with bulimia, 7 with features of the restricting subtype of anorexia nervosa, and 6 with bulimic subtype of anorexia nervosa. The mean basal levels of TSH, PRL, and GH did not differ among the three groups. A delayed TSH response was found in 86% of the restricting anorectics, 80% of the bulimic anorectics, and 22% of the bulimics. The PRL response was normal in all patients, with no significant difference among the three groups. Elevated basal GH levels were found in 29% of the restricting anorectics, 33% of the bulimic anorectics, and 33% of the bulimics. An abnormal GH increase after TRH stimulation was observed in 50% of the restricting anorectics, 20% of the bulimic anorectics, and 13% of the bulimics. These results suggest that some patients with bulimia, and some with anorexia nervosa, have a hypothalamic dysfunction. These neuroendocrine abnormalities do not appear to be due solely to low weight or to metabolic changes resulting from binge eating and are not associated with depressive symptoms.