Normal inhibin B levels suggest partial preservation of gonadal function in adult male patients with anorexia nervosa

Mechanisms and predictors of menses resumption once normal weight is reached in anorexia nervosa

BACKGROUND

In cases of Anorexia Nervosa (AN), achieving weight gain recovery beyond the lower limits set by the World Health Organization and normalizing classical nutritional markers appears to be essential for most patients. However, this is not always adequate to restore menstrual cycles. This discrepancy can cause concern for both patients and healthcare providers, and can impact the medical management of these individuals. Thus, the purpose of this study was to assess the ability of anthropometric and hormonal factors to predict the resumption of menstrual cycles in individuals with anorexia nervosa upon reaching a normal body weight.

METHOD

Patients with AN who had achieved a normal Body Mass Index but had not yet resumed their menstrual cycles (referred to as ANRec) were evaluated on two occasions: first at visit 1 and then again 6 months later, provided their body weight remained stable over this period (visit 2). Among the 46 ANRec patients who reached visit 2, they were categorized into two groups: 20 with persistent amenorrhea (PA-ANRec) and 26 who had regained their menstrual cycles (RM-ANRec). Anthropometric measurements, several hormone levels, Luteinizing Hormone (LH) pulsatility over a 4-h period, and LH response to gonadotropin-releasing hormone injection (LH/GnRH) were then compared between the two groups at visit 1.

RESULTS

Patients in the RM-ANRec group exhibited higher levels of follicular stimulating hormone, estradiol, inhibin B, LH/GnRH, and lower levels of ghrelin compared to those in the PA-ANRec group. Analysis of Receiver Operating Characteristic curves indicated that having ≥ 2 LH pulses over a 4-h period, LH/GnRH levels ≥ 33 IU/l, and inhibin B levels > 63 pg/ml predicted the resumption of menstrual cycles with a high degree of specificity (87%, 100%, and 100%, respectively) and sensitivity (82%, 80%, and 79%, respectively).

CONCLUSIONS

These three hormonal tests, of which two are straightforward to perform, demonstrated a high predictive accuracy for the resumption of menstrual cycles. They could offer valuable support for the management of individuals with AN upon achieving normalized weight. Negative results from these tests could assist clinicians and patients in maintaining their efforts to attain individualized metabolic targets.

TRIAL REGISTRATION

IORG0004981.

Growth factors in anorexia nervosa: a systematic review and meta-analysis of cross-sectional and longitudinal data

OBJECTIVES

Growth factors are signalling molecules that play roles in the survival, proliferation, migration, and differentiation of cells. Studies have found alterations in specific growth factors in anorexia nervosa (AN).

METHODS

This systematic review and meta-analysis examined articles from three databases, measuring growth factors in AN cross-sectionally and longitudinally, and in recovered AN (rec-AN) cross-sectionally. Random-effects meta-analyses were conducted for brain-derived neurotrophic factor (BDNF) and insulin growth factor-I (IGF-1) for cross-sectional and longitudinal studies.

RESULTS

A total of 82 studies were included: 56 cross-sectional (BDNF: n = 15; IGF-1: n = 41) and 24 longitudinal (BDNF: n = 5; IGF-1: n = 19) were meta-analysed and 20 studies were narratively synthesised. In cross-sectional analyses, BDNF and IGF-1 were lower in AN compared to controls, and BDNF was marginally greater in rec-AN compared to controls. In longitudinal meta-analyses, BDNF and IGF-1 increased from baseline to follow-up. Cross-sectional subgroup analyses revealed no differences in BDNF between controls and AN binge-eating/purging subtypes.

CONCLUSIONS

It is likely that the low BDNF and IGF-1 levels found in AN are consequences of starvation, which are reversible with weight restoration. The increase in BDNF and IGF-1 during therapeutic weight restoration might improve neuroplasticity, which is the basis of learning, and thus psychotherapeutic success.

Dehydroepiandrosterone status and efficacy of dehydroepiandrosterone supplementation for bone health in anorexia nervosa: A systematic review and meta-analysis

OBJECTIVE

This study was designed to determine the status of dehydroepiandrosterone (DHEA) in women with anorexia nervosa (AN) and to assess the efficacy of DHEA supplementation as a treatment for bone health in women with AN.

METHOD

Studies were retrieved from the PubMed, Embase, Cochrane Library, MEDLINE, and Scopus databases from inception to February 14, 2022. Observational studies that compared serum DHEA levels between women with AN and healthy controls were included for meta-analysis, and randomized controlled trials (RCTs) that evaluated the effects of DHEA supplementation on bone mass were reviewed.

RESULTS

Meta-analysis of 15 cross-sectional studies revealed that patients with AN had significantly elevated serum DHEA levels (mean difference (MD) = 311.63 ng/dl; 95% confidence interval (CI), 78.01-545.25) and reduced DHEAS levels (MD = -24.90 μg/dl; 95% CI, -41.72 to -8.07) compared with healthy controls. A systematic review of seven RCTs found that DHEA monotherapy does not improve bone mineral density (BMD) compared with placebo after adjusting for weight gain. While the combination of DHEA and conjugated oral contraceptives has led to increased bone strength and decreased bone loss, the beneficial effect appears to be limited to older adolescents and adults with closed physes. Potential detrimental effects on BMD were identified in younger adolescents with open physes in one study.

DISCUSSION

Due to the lack of apparent benefit of DHEA in women with AN and its potential detrimental effect on BMD in young patients with AN, current evidence does not support the use of DHEA.

PUBLIC SIGNIFICANCE

This study demonstrates that women with anorexia nervosa have abnormal levels of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS), which have been suggested by previous studies to play a role in the development of low bone density in this condition. However, current evidence does not support the use of DHEA as a treatment to preserve bone health in patients with anorexia nervosa given the lack of clear benefit following its use and also because of a potential detrimental effect on bone mineral density in young patients with anorexia nervosa.

Dysregulation of the Hypothalamic-Pituitary-Testicular Axis due to Energy Deficit

CONTEXT

Although gonadal axis dysregulation from energy deficit is well recognized in women, the effects of energy deficit on the male gonadal axis have received much less attention.

EVIDENCE ACQUISITION

To identify relevant articles, we conducted PubMed searches from inception to May 2021.

EVIDENCE SYNTHESIS

Case series and mechanistic studies demonstrate that energy deficit (both acutely over days or chronically over months) either from inadequate energy intake and/or excessive energy expenditure can lower serum testosterone concentration as a result of hypothalamic-pituitary-testicular (HPT) axis dysregulation in men. The extent to which this has clinical consequences that can be disentangled from the effects of nutritional insufficiency, concomitant endocrine dysregulation (eg, adrenal and thyroid axis), and coexisting comorbidities (eg, depression and substance abuse) is uncertain. HPT axis dysfunction is primarily the result of loss of GnRH pulsatility resulting from a failure of leptin to induce kisspeptin signaling. The roles of neuroendocrine consequences of depression, hypothalamic-pituitary-adrenal axis activation, proinflammatory cytokines, Ghrelin, and genetic susceptibility remain unclear. In contrast to hypogonadism from organic pathology of the HPT axis, energy deficit-associated HPT dysregulation is functional, and generally reversible by restoring energy balance.

CONCLUSIONS

The clinical management of such men should aim to restore adequate nutrition and achieve and maintain a healthy body weight. Psychosocial comorbidities must be identified and addressed. There is no evidence that testosterone treatment is beneficial. Many knowledge gaps regarding epidemiology, pathophysiology, and treatment remain and we highlight several areas that require future research.

Adipokines in anorexia nervosa: A systematic review and meta-analysis

OBJECTIVE

The association between adipokine dysregulation and weight loss of patients with anorexia nervosa (AN) has been long investigated, in search of a causal relationship. We sought to: a) synthesize the available evidence on potential differences between AN patients and controls with regards to adipokine measurements (namely, leptin, adiponectin, resistin, soluble leptin receptor, visfatin, vaspin and omentin), b) estimate the potential differences between constitutionally thin (CT) subjects and AN patients, and c) present the available evidence with regards to biomarker efficacy of adipokines in AN.

METHODS

A structured literature search, last updated in 2/2019, was conducted in the following databases: MEDLINE, clinicaltrials.gov, PsycINFO, PSYNDEX and WHO Registry Network. The primary outcome was the standardized mean difference of each adipokine between AN patients and controls of normal BMI. Secondary outcomes included the correlation of leptin with BMI and bone mineral density among AN patients. The study protocol is published in PROSPERO (CRD42018116767).

RESULTS

In a total of 622 screened studies, after exclusion of non-relevant articles and duplicates, 84 reports on leptin, 31 reports on adiponectin, 12 on resistin, 10 on soluble leptin receptor, 5 on visfatin, 3 on vaspin and omentin were finally included in the meta-analysis. Publication bias assessment underlined the possibility of non-significant studies being underrepresented; still, significant heterogeneity renders this statement inconclusive. Leptin [ELISA: SMD (95% CI): -3.03 (-4, -2.06)], radioimmunoassay [RIA: -3.84 (-4.71, -2.98)] and resistin [-1.67 (-2.85, -0.48)] were significantly lower in patients with AN compared with controls, whereas visfatin decrease did not reach significance (-2.03 (-4.38, 0.3). Mean adiponectin, vaspin and soluble leptin receptor levels were significantly higher. In subgroup analysis, a significantly attenuated SMD was reported in ELISA studies compared with RIA studies. Leptin was significantly lower in AN patients compared to CT subjects and BMI marginally did not appear to confound the result. In all analyses, except for the correlation of leptin with BMI in AN patients, high heterogeneity was present. Meta-regression analysis indicated a potential confounding action of controls' BMI and age on leptin SMD and between-assay differences. Publication bias assessment underlined the possibility of nonsignificant studies being underrepresented; still, further investigation did not corroborate this and significant heterogeneity renders this statement inconclusive.

CONCLUSION

A distinct profile of adipokine dysregulation is apparent in AN patients, following the anticipated pattern of low BMI. A precise estimation of the magnitude is hindered by heterogeneity, partly caused by varying assays and methodologies. Interestingly, while mean leptin levels are lower in AN subjects compared with constitutionally thin women, there is an overlap in individual levels between the two groups and therefore, they cannot be used to differentiate between these states.

Metabolic and neuroendocrine adaptations to undernutrition in anorexia nervosa: from a clinical to a basic research point of view

The exact mechanisms linking metabolic and neuroendocrine adaptations to undernutrition and the pathophysiology of anorexia nervosa (AN) are not fully understood. AN is a psychiatric disorder of complex etiology characterized by extreme starvation while the disease is progressing into a chronic state. Metabolic and endocrine alterations associated to this disorder are part of a powerful response to maintain whole body energy homeostasis. But these modifications may also contribute to associated neuropsychiatric symptoms (reward abnormalities, anxiety, depression) and thus participate to sustain the disease. The current review presents data with both a clinical and basic research point of view on the role of nutritional and energy sensors with neuroendocrine actions in the pathophysiology of the disease, as they modulate metabolic responses, reproductive functions, stress responses as well as physical activity. While clinical data present a full description of changes occurring in AN, animal models that integrate either spontaneous genetic mutations or experimentally-induced food restriction with hyperactivity and/or social stress recapitulate the main metabolic and endocrine alterations of AN and provide mechanistic information between undernutrition state and symptoms of the disease. Further progress on the central and peripheral mechanism involved in the pathophysiology of eating disorders partly relies on the development and/or refinement of existing animal models to include recently identified genetic traits and better mimic the complex and multifactorial dimensions of the disease.

A comparison of clinical characteristics between adolescent males and females with eating disorders

BACKGROUND

Eating disorders (ED) are serious disorders that have a negative impact on both the psychological and the physiological well-being of the afflicted. Despite the fact that ED affect both genders, males are often underrepresented in research and when included the sample sizes are often too small for separate analyses. Consequently we have an unclear and sometimes contradictory picture of the clinical characteristics of males with ED. The aim of the present study was to improve our understanding of the clinical features of adolescent males with eating disorders.

METHODS

We compared age at presentation, weight at presentation, history of significantly different premorbid weight and psychiatric (Attention Deficit Hyperactivity Disorder (ADHD)) and somatic comorbidity (celiac disease and diabetes) of 58 males to 606 females seeking medical care for eating disorders at the Children's Hospital in Uppsala, Sweden during the years 1999-2012. As all boys were diagnosed with either AN or Other Specified Feeding or Eating Disorder (OSFED) atypical AN, the age and weight comparisons were limited to those girls fulfilling the diagnostic criteria for AN or OSFED atypical AN.

RESULTS

There was no significant difference in age at presentation. Differences in weight at presentation and premorbid weight history were mixed. A significantly higher percentage of males had a history of a BMI greater than two standard deviations above the mean for their corresponding age group. As well, there was a higher prevalence of ADHD among the males whereas celiac disease and diabetes only was found among the females.

CONCLUSIONS

A better understanding of the clinical characteristics of males with ED at presentation should improve our ability to identify males with ED and thereby aid in tailoring the best treatment alternatives.

Endocrine consequences of anorexia nervosa

Anorexia nervosa is prevalent in adolescents and young adults, and endocrine changes include hypothalamic amenorrhoea; a nutritionally acquired growth-hormone resistance leading to low concentrations of insulin-like growth factor-1 (IGF-1); relative hypercortisolaemia; decreases in leptin, insulin, amylin, and incretins; and increases in ghrelin, peptide YY, and adiponectin. These changes in turn have harmful effects on bone and might affect neurocognition, anxiety, depression, and the psychopathology of anorexia nervosa. Low bone-mineral density (BMD) is particularly concerning, because it is associated with changes in bone microarchitecture, strength, and clinical fractures. Recovery leads to improvements in many--but not all--hormonal changes, and deficits in bone accrual can persist. Oestrogen-replacement therapy, primarily via the transdermal route, increases BMD in adolescents, although catch-up is incomplete. In adults, oral oestrogen--combined with recombinant human IGF-1 in one study and bisphosphonates in another--increased BMD, but not to the normal range. More studies are necessary to investigate the optimum therapeutic approach in patients with, or recovering from, anorexia nervosa.