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Biomedical subjects

A B Levy

Publications and source records attributed to A B Levy.

At least 19 recordsLinked to original sources

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 Unpublished data suggest bulimics may have a gonadotropin profile distinct from either AN or depression, as well as a variety of other endocrinopathies.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.

Bulimia↗

How are depression and bulimia related?

The idea that bulimia may be related to affective illness was encouraged by early reports of a high prevalence of clinical depression in bulimic patients as well as a high lifetime prevalence of depression in the families of these patients. More recent evidence suggests, however, that bulimia and major depression are distinct entities. The authors review clinical data, family studies, pharmacotherapy, and the neurobiology of bulimia and discuss the nature of the relationship between depression and bulimia.

Antidepressive Agents↗

Inability to predict postdexamethasone cortisol levels by serum sodium levels.

Each of 42 hospitalized patients with unipolar major depression received a dexamethasone suppression test (DST) and had blood drawn for serum sodium and potassium tests within 3 days of admission. Unlike the patients in an earlier report by Tollefson et al., these patients showed no correlations between the DST results and the serum sodium levels. Although the DST identified depressive subtypes accurately, the serum sodium levels did not predict the DST results in this study.

Depressive Disorder↗

Pituitary response to TRH in bulimia.

The response to thyrotropin-releasing hormone (TRH) of thyroid-stimulating hormone (TSH), growth hormone (GH), and prolactin (PRL) was examined in nine normal weight female bulimics without endogenous depression and eight female controls. Four bulimics had delayed peak TSH response, but none demonstrated a blunted TSH response, unlike that which has been reported in endogenous depression. Bulimics had elevated mean +/- SD serum GH levels (controls 1.6 +/- 1.4 ng/ml, bulimics 5.6 +/- 3.9) and an inappropriate GH release following TRH. Their mean +/- SD serum PRL (3.1 +/- 1.7 ng/ml) was lower than that of controls (4.7 +/- 1.3); however, the PRL response to TRH was significantly greater in bulimics than in controls. These data show that neuroendocrine abnormalities exist in normal weight bulimic women without endogenous depression and provide further evidence for a neuroendocrine component to this illness.

Adolescent↗

Growth hormone and somatomedin-C in bulimia.

Somatomedin-C (SOM-C) concentrations are regulated by circulating growth hormone (GH) concentrations; however, other factors, such as nutrition, also influence SOM-C concentrations. We evaluated the GH-SOM-C axis in seven normal-weight female bulimics one day after hospital admission, and in seven age-, sex-, and weight-matched normal controls. Subjects were medication-free for at least one month. Fasting morning serum GH concentrations were higher in all bulimics (range 2.5-13.3 ng/ml) than in all controls (range less than 1.0-1.8 ng/ml). The mean (+/- SD) maximum GH response to TRH (500 micrograms) was greater in the bulimics (12.9 +/- 4.9 ng/ml) than in the controls (3.7 +/- 2.7 ng/ml) (p less than .001). Despite this GH elevation, the mean (+/- SD) SOM-C concentration was comparable in the bulimics (2.0 +/- 0.6 U/ml) and the controls (1.6 +/- 0.8 U/ml). This suggests that SOM-C generation is resistant to the elevated circulating GH in bulimia and that SOM-C is not inhibiting GH secretion in the pituitary-hypothalamic axis.

Adult↗

Depression associated with nifedipine-induced calcium channel blockade.

Four cases are reported in which substantial depression was associated with the use of the calcium channel blocker nifedipine. In one instance, a patient became unresponsive to treatment with nortriptyline when nifedipine was introduced. In each case, the depression resolved following discontinuation of nifedipine. Possible mechanisms by which nifedipine may influence affective states are discussed.

Aged↗

EEG evidence of epileptiform paroxysms in rapid cycling bipolar patients.

Electroencephalographic (EEG) abnormalities have been described in patients with mood disorders. In an effort to determine if rapid cycling bipolar affective disorder patients may demonstrate more prevalent EEG paroxysmal activity than patients with non-rapid cycling mood disorders, we studied five consecutively identified bipolar patients who cycled at least four times a year. They were compared with 25 consecutive affective disorder patients who received an EEG before electroconvulsive therapy. Three of the five rapid cycling patients had bitemporal paroxysmal sharp waves as demonstrated by EEG but no psychomotor evidence of epilepsy. None of the 25 comparison patients had EEG abnormalities. Four of the five rapid cyclers reported a family history of affective disorder, including the three who had paroxysms.

Adolescent↗

REM and delta sleep in anorexia nervosa and bulimia.

Several recent investigations have suggested that neurobiological similarities may exist between patients with eating disorders and those with depression. We performed polysomnograms for two consecutive nights on nine bulimic and six anorectic patients who had no concomitant diagnosis of endogenous depression. The rapid eye movement (REM) latency, REM density, and delta sleep of these subjects on night 2 were compared to those of 10 healthy controls of similar ages. Contrary to reports of shortened REM latency and increased REM density in depressed patients, we did not find significant REM differences between eating disorder patients without endogenous depression and healthy control subjects. Low weight anorectics did appear to have less delta sleep than did controls. These findings do not support the contention that eating disorders are variants of affective disorders.

Adolescent↗

DST and TRH stimulation test in mood disorder subtypes.

Both the dexamethasone suppression test (DST) and the thyrotropin-releasing hormone (TRH) stimulation test have been reported to be useful in subtyping some depression diagnoses. Whether the DST discriminates delusional from nondelusional depression remains controversial, but this possibility has not been studied for the TRH test. The authors evaluated DST and TRH test results in 29 depressed hospitalized patients; both tests significantly discriminated patients with nonendogenous depression from those with endogenous depression. Furthermore, postdexamethasone cortisol levels but not the change in thyroid-stimulating hormone discriminated the patients with endogenous delusional depression from those with endogenous nondelusional depression.

Adult↗

Reduced serum tricyclic levels due to gel separators.

Sixty-three blood samples were obtained from 48 subjects taking tricyclic antidepressants. Samples were simultaneously collected in Becton-Dickinson Vacutainer tubes for measurement of serum and plasma tricyclic antidepressant concentrations. Serum was drawn into red stopper tubes (without gel separator) and into speckled stopper serum separator tubes (with gel separator), while plasma was collected in green stopper tubes (heparinized). Imipramine, desipramine, amitriptyline, and nortriptyline concentrations were all significantly lower in serum separator samples than in either plasma or red stopper serum collection tubes. Serum and plasma concentrations were similar.

Antidepressive Agents, Tricyclic↗