The significance of routine laboratory analyses in the assessment of teenage girls with eating disorders and weight loss

Structural Neuroimaging of Anorexia Nervosa: Future Directions in the Quest for Mechanisms Underlying Dynamic Alterations

Anorexia nervosa (AN) is a serious eating disorder characterized by self-starvation and extreme weight loss. Pseudoatrophic brain changes are often readily visible in individual brain scans, and AN may be a valuable model disorder to study structural neuroplasticity. Structural magnetic resonance imaging studies have found reduced gray matter volume and cortical thinning in acutely underweight patients to normalize following successful treatment. However, some well-controlled studies have found regionally greater gray matter and persistence of structural alterations following long-term recovery. Findings from diffusion tensor imaging studies of white matter integrity and connectivity are also inconsistent. Furthermore, despite the severity of AN, the number of existing structural neuroimaging studies is still relatively low, and our knowledge of the underlying cellular and molecular mechanisms for macrostructural brain changes is rudimentary. We critically review the current state of structural neuroimaging in AN and discuss the potential neurobiological basis of structural brain alterations in the disorder, highlighting impediments to progress, recent developments, and promising future directions. In particular, we argue for the utility of more standardized data collection, adopting a connectomics approach to understanding brain network architecture, employing advanced magnetic resonance imaging methods that quantify biomarkers of brain tissue microstructure, integrating data from multiple imaging modalities, strategic longitudinal observation during weight restoration, and large-scale data pooling. Our overarching objective is to motivate carefully controlled research of brain structure in eating disorders, which will ultimately help predict therapeutic response and improve treatment.

Weight restoration therapy rapidly reverses cortical thinning in anorexia nervosa: A longitudinal study

Structural magnetic resonance imaging studies have documented reduced gray matter in acutely ill patients with anorexia nervosa to be at least partially reversible following weight restoration. However, few longitudinal studies exist and the underlying mechanisms of these structural changes are elusive. In particular, the relative speed and completeness of brain structure normalization during realimentation remain unknown. Here we report from a structural neuroimaging study including a sample of adolescent/young adult female patients with acute anorexia nervosa (n=47), long-term recovered patients (n=34), and healthy controls (n=75). The majority of acutely ill patients were scanned longitudinally (n=35): at the beginning of standardized weight restoration therapy and again after partial weight normalization (>10% body mass index increase). High-resolution structural images were processed and analyzed with the longitudinal stream of FreeSurfer software to test for changes in cortical thickness and volumes of select subcortical regions of interest. We found globally reduced cortical thickness in acutely ill patients to increase rapidly (0.06 mm/month) during brief weight restoration therapy (≈3 months). This significant increase was predicted by weight restoration alone and could not be ascribed to potentially mediating factors such as duration of illness, hydration status, or symptom improvements. By comparing cortical thickness in partially weight-restored patients with that measured in healthy controls, we confirmed that cortical thickness had normalized already at follow-up. This pattern of thinning in illness and rapid normalization during weight rehabilitation was largely mirrored in subcortical volumes. Together, our findings indicate that structural brain insults inflicted by starvation in anorexia nervosa may be reversed at a rate much faster than previously thought if interventions are successful before the disorder becomes chronic. This provides evidence drawing previously speculated mechanisms such as (de-)hydration and neurogenesis into question and suggests that neuronal and/or glial remodeling including changes in macromolecular content may underlie the gray matter alterations observed in anorexia nervosa.

Eating disorders and biochemical composition of saliva: a retrospective matched case-control study

This study aimed to compare the biochemical composition of saliva from patients with eating disorders (EDs) with saliva from control subjects with no ED. All patients who initiated outpatient treatment in an ED clinic during a 12‐month period were invited to participate. Of the 65 patients who started treatment during the period, 54 (50 female patients/four male patients; mean age: 21.5 yr) agreed to participate. The controls were 54 sex‐ and age‐matched patients from a dental health clinic. All participants completed a questionnaire and underwent dental clinical examinations, including laboratory analyses of saliva. The proportion of subjects with unstimulated salivary hyposalivation was lower in the ED group and not correlated with intake of xerogenic drugs. Significant differences in the biochemical composition of saliva were found almost exclusively in the unstimulated state, with albumin, inorganic phosphate, aspartate aminotransferase (ASAT), chloride, magnesium, and total protein all being significantly higher in the ED group. Conditional logistic regression showed that higher ASAT and total protein concentrations were relatively good predictors of ED, with sensitivity and specificity of 65% and 67%, respectively. In conclusion, elevated salivary concentrations of ASAT and total protein may serve as indicators of ED as well as of disease severity. Future studies are needed to corroborate these initial findings.

[Hematological changes in adolescent anorexia nervosa]

OBJECTIVE

Hematological changes often occur in patients with acute anorexia nervosa (AN). However, the relationship between these disturbances and other clinical parameters remains unclear.

METHOD

Leucocyte, erythrocyte, and thrombocyte counts as well as hematocrit, hemoglobin, and differential blood counts were collected at admission and after weight restoration in 88 female adolescent patients with the diagnosis of AN according to DSM-IV. These were then compared to clinical parameters.

RESULTS

At admission, there were mild changes in the blood count, most of which, however, were reversible after weight gain. Patients with a greater weight loss, a lower age-adjusted BMI, and a history of taking psychotropic drugs were more likely to develop hematological abnormalities.

CONCLUSIONS

Although most of the hematological changes in adolescent patients with AN were mild, patients with high weight loss and/or low age-adjusted BMI as well as those on psychotropic medication should be monitored carefully in order to avoid severe medical complications. An altered immune function in adult patients with chronic AN might contribute to a higher rate of infections and thus to an increased mortality.

No unexpected adverse events and biochemical side effects of olanzapine as adjunct treatment in adolescent girls with eating disorders

OBJECTIVE

Olanzapine has been recently tried to relieve anxiety and hyperactivity in adolescents with eating disorders (EDs). Presently, the side effects of the drug have been evaluated.

METHOD

Forty-seven adolescents with EDs were followed up by repeated blood sampling before, during, and at 3 months after medication with olanzapine.

RESULTS

Olanzapine medication was discontinued in three patients because of galactorrhea, seizures, and raised liver enzyme activities, respectively. There was a normalization of glucose, insulin, and lipid profiles during treatment, which was related to weight gain and resumption of menstruations but not to medication. Increases in thyroid-stimulating hormone and prolactin were related to olanzapine medication and comedication with selective serotonine reuptake inhibitors. Three months after discontinuing medication, there were no persisting biochemical effects.

CONCLUSION

The side effects observed were those previously described for olanzapine. Most biochemical changes were related to weight (change) and amenorrhea and not to medication. Placebo-controlled studies are needed to investigate the efficacy of olanzapine in adolescents with EDs.

S100B in underweight and weight-recovered patients with anorexia nervosa

Anorexia nervosa (AN) commonly arises during adolescence, leading to interruptions of somatic and psychological development as well as to cortical atrophy and reductions of brain volume. While most brain changes shift towards normal with weight restoration, it is not certain whether they are related to the loss of brain cells, neuropil or merely due to fluid shifts. We measured S100B serum concentrations and psychometric characteristics in 34 patients with acute AN, 19 weight-recovered patients and 35 healthy control women (HCW). Plasma tryptophan and leptin levels were determined as markers for malnutrition and neuroendocrine adaptation to semi-starvation. Peripheral S100B concentrations of acute and former AN patients were not elevated and not statistically different from HCW. BMI, peripheral leptin levels and measures of psychopathology as well as executive cognitive functioning did not correlate with S100B. Plasma tryptophan was positively related to S100B. Our results are in line with our previous findings showing unaltered GFAP and NSE plasma levels in patients with acute AN. Together they do not support hypotheses comprising the degeneration of glial or neuronal cells to explain common signs of brain atrophy in patients with acute AN.

Cholinesterase and other serum liver enzymes in underweight outpatients with eating disorders

OBJECTIVE

The present study aimed to evaluate serum liver enzymes in underweight outpatients with anorexia nervosa (A-NERV) or eating disorders not otherwise specified (EDNOS).

METHOD

Serum alanine amino transferase (ALT), aspartate amino transferase (AST), lactic dehydrogenase (LDH), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), and cholinesterase (CHE) were determined in 97 patients with A-NERV, 66 patients with EDNOS, and 56 controls.

RESULTS

In the A-NERV group AST, LDH, and GGT were higher, as compared with controls, and inversely related to weight, while ALP and CHE were lower. AST and GGT increased and CHE decreased in patients with EDNOS. Hypertransaminasemia occurred in 14.4 and 15.2%, and low CHE in 29.9% of the A-NERV group and 13.6% and EDNOS group, respectively. Three or more abnormalities were found in 9.3% of patients with A-NERV and 7.5% of those with EDNOS.

CONCLUSION

Abnormalities in serum liver enzymes are common in outpatients with eating disorders plus underweight. CHE might be considered as a marker of the effects of primary malnutrition on liver function.

Insulin-like growth factor-1 as an indicator of nutrition during treatment of adolescent girls with eating disorders

AIM

The use of serum insulin-like growth factor-1 (IGF-1) concentrations as an index of nutrition has been analysed in teenage girls with eating disorders and weight loss.

METHOD

Blood samples for analysis of IGF-1 were obtained at 349 assessments of 302 patients and biweekly during 56 treatment periods in 46 patients. IGF-1 was related to body size, weight loss, degree of leanness (BMI standard deviation score) and rate of weight loss.

RESULTS

At assessment, when most of the girls were on a weight-losing course, serum IGF-1 concentrations were low. Weight loss immediately prior to assessment was the most important predictor of IGF-1. Together with measurements of weight, height, weight loss and BMI standard deviation score the rate of weight loss predicted IGF-1 to 32-55%. During treatment when there was net weight gain, IGF-1 increased in parallel with the BMI standard deviation score, a measure of leanness, and was also influenced by the short-term weight trend.

CONCLUSION

The serum IGF-1 concentration is an indicator of nutritional status in adolescents with eating disorders. It is sensitive to short-term weight changes measured in a clinical setting and could be used at assessment and to monitor nutritional rehabilitation.

Haematological changes and iron status in teenage girls with eating disorders and weight loss-the importance of menstrual status

AIM

To study haematological changes and iron stores in teenage girls with eating disorders and weight loss.

METHODS

Blood haemoglobin concentration, white blood cell and thrombocyte count and serum ferritin concentration were measured at assessments of 446 subjects.

RESULTS

Haemoglobin concentrations, leukocyte and thrombocyte counts were related to weight and rate of weight loss but were largely within reference ranges. Serum ferritin concentrations were high in girls with amenorrhea and related to weight and rate of weight loss. Girls who retained menstruations had low serum ferritin concentrations and 37% had depleted iron stores (serum ferritin<16 microg/L).

CONCLUSION

Anaemia, leukopenia and thrombocytopenia are uncommon in teenage girls with eating disorders and weight loss. When present, other diseases causing haematological changes should be considered. In amenorrhoic girls muscle catabolism increases serum ferritin concentrations which may give a false impression of an adequate iron status. This is unmasked in girls with retained menstruations who often have depleted iron stores.