Selective determinants of low bone mineral mass in adult women with anorexia nervosa

Anorexia Nervosa and Osteoporosis

Patients with anorexia nervosa (AN) often experience low bone mineral density (BMD) and increased fracture risk, with low body weight and decreased gonadal function being the strongest predictors of the observed bone mineral deficit and fractures. Other metabolic disturbances have also been linked to bone loss in this group of patients, including growth hormone resistance, low insulin-like growth factor-1 (IGF-1) concentrations, low leptin concentrations, and hypercortisolemia. However, these correlations lack definitive evidence of causality. Weight restoration and resumption of menstrual function have the strongest impact on increasing BMD. Other potential treatment options include bisphosphonates and teriparatide, supported by data from small clinical trials, but these agents are not approved for the treatment of low BMD in adolescents or premenopausal women with AN.

The Female Athlete Triad/Relative Energy Deficiency in Sports (RED-S)

In a healthy athlete, the caloric intake is sufficient for sports energy needs and body physiological functions, allowing a balance between energy availability, bone metabolism, and menstrual cycle. On the other hand, an imbalance caused by low energy availability due to a restrictive diet, eating disorders or long periods of energy expenditure leads to multisystemic deregulation favoring the essential functions of the body. This phenomenon, described as the female athlete triad, occurs in a considerable percentage of high-performance athletes, with harmful consequences for their future. The present review was carried out based on a critical analysis of the most recent publications available and aims to provide a global perception of the topic relative energy deficit in sport (RED-S). The objective is to promote the acquisition of more consolidated knowledge on an undervalued theme, enabling the acquisition of preventive strategies, early diagnosis and/or appropriate treatment.

Anorexia Nervosa and Osteoporosis: Pathophysiology and Treatment

Anorexia nervosa (AN) affects 2.9 million people, many of whom experience bone loss and increased fracture risk. In this article, we review data on the underlying pathophysiology of AN-related osteoporosis and possible approaches to disease management. Available research suggests that low body weight and decreased gonadal function are the strongest predictors of bone loss and fractures in patients with AN. Additionally, other metabolic disturbances have been linked to bone loss, including growth hormone resistance, low leptin concentrations, and hypercortisolemia, but those correlations are less consistent and lack evidence of causality. In terms of treatment of AN-related bone disease, weight gain has the most robust impact on bone mineral density (BMD). Restoration of gonadal function seems to augment this effect and may independently improve BMD. Bisphosphonates, insulin-like growth factor 1 supplementation, and teriparatide may also be reasonable considerations, however need long-term efficacy and safety data.

Oral contraceptives partially protect from bone loss in young women with anorexia nervosa

OBJECTIVE

To evaluate the potentially protective effects of oral contraceptives (OC) on bone loss in a large population of young women with anorexia nervosa (AN).

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENT(S)

Three hundred and five patients with AN (99 of them using OC) and 121 age-matched controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Areal bone mineral density (aBMD) evaluated by dual-energy X-ray absorptiometry and bone turnover markers, with leptin evaluated concomitantly.

RESULT(S)

Although the AN patients taking OC presented lower aBMD compared with the controls at all bone sites, the whole body excepted, their aBMD values were systematically higher than those of AN patients who were not taking OC for the whole body and the lumbar spine, femoral neck, hip, and radius. These differences persisted after multiple adjustments. Preservation of aBMD improved with longer durations of OC use and shorter delays between disease onset and the start of OC. Moreover, patients with the lowest body mass index showed the best bone tissue responses to OC. Bone formation markers were systematically lower in the two groups of patients with AN compared with the controls. The markers of bone resorption were normalized in AN patients using OC.

CONCLUSION(S)

Although OC use does not provide total protection of aBMD, our data suggest that OC might be prescribed for young women with AN to limit their bone loss.

Effects of the two types of anorexia nervosa (binge eating/purging and restrictive) on bone metabolism in female patients

OBJECTIVE

This study compared the profiles of the two types of anorexia nervosa (AN; restrictive: AN-R, and binge eating/purging: AN-BP) in terms of body composition, gynaecological status, disease history and the potential effects on bone metabolism.

DESIGN

Two hundred and eighty-six women with AN (21.8 ± 6.5 years; 204 AN-R and 82 AN-BP) and 130 age-matched controls (CON; 22.6 ± 6.8 years) were enrolled. Areal bone mineral density (aBMD) was determined using DXA and resting energy expenditure (REE) was indirectly assessed using calorimetry. Markers of bone formation (osteocalcin [OC], procollagen type I N-terminal propeptide [PINP] and resorption (type I-C telopeptide breakdown products [CTX]) and leptin were concomitantly evaluated.

RESULTS

Anorexia nervosa patients presented an alteration in aBMD and bone turnover. When compared according to type, AN-BP were older than AN-R and showed less severe undernutrition, lower CTx levels, longer duration of AN, and higher REE levels and aBMD at radius and lumbar spine. After adjustment for age, weight and hormonal contraceptive use, the aBMD and CTx differences disappeared. In both AN groups, aBMD was positively correlated with anthropometric parameters and negatively correlated with durations of AN and amenorrhoea, the bone formation markers (OC and PINP) and the leptin/fat mass ratio. REE was positively correlated with aBMD in AN-R patients only.

CONCLUSIONS

This study shows the profiles of AN patients according to AN type. However, the impact of the profile characteristics on bone status, although significant, was minor and disappeared after multiple adjustments. The positive correlation between REE and aBMD reinforces the concept that energy disposal and bone metabolism are strongly interdependent.

Bone metabolism in anorexia nervosa and hypothalamic amenorrhea

Anorexia nervosa (AN) and hypothalamic amenorrhea (HA) are states of chronic energy deprivation associated with severely compromised bone health. Poor bone accrual during adolescence followed by increased bone loss results in lifelong low bone density, degraded bone architecture, and higher risk of fractures, despite recovery from AN/HA. Amenorrhea is only one of several compensatory responses to the negative energy balance. Other hypothalamic-pituitary hormones are affected and contribute to bone deficits, including activation of hypothalamic-pituitary-adrenal axis and growth hormone resistance. Adipokines, particularly leptin, provide information on fat/energy stores, and gut hormones play a role in the regulation of appetite and food intake. Alterations in all these hormones influence bone metabolism. Restricted in scope, current pharmacologic approaches to improve bone health have had overall limited success.

Functional Hypothalamic Amenorrhea: An Endocrine Society Clinical Practice Guideline

COSPONSORING ASSOCIATIONS

The American Society for Reproductive Medicine, the European Society of Endocrinology, and the Pediatric Endocrine Society. This guideline was funded by the Endocrine Society.

OBJECTIVE

To formulate clinical practice guidelines for the diagnosis and treatment of functional hypothalamic amenorrhea (FHA).

PARTICIPANTS

The participants include an Endocrine Society-appointed task force of eight experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Endocrine Society committees and members and cosponsoring organizations reviewed and commented on preliminary drafts of this guideline.

CONCLUSIONS

FHA is a form of chronic anovulation, not due to identifiable organic causes, but often associated with stress, weight loss, excessive exercise, or a combination thereof. Investigations should include assessment of systemic and endocrinologic etiologies, as FHA is a diagnosis of exclusion. A multidisciplinary treatment approach is necessary, including medical, dietary, and mental health support. Medical complications include, among others, bone loss and infertility, and appropriate therapies are under debate and investigation.

Vitamin D: not just the bone. Evidence for beneficial pleiotropic extraskeletal effects

Vitamin D is a fat-soluble vitamin and a steroid hormone that plays a central role in maintaining calcium-phosphorus and bone homeostasis in close interaction with parathyroid hormone, acting on its classical target tissues, namely, bone, kidney, intestine, and parathyroid glands. However, vitamin D endocrine system regulates several genes (about 3 % of the human genome) involved in cell differentiation, cell-cycle control, and cell function and exerts noncalcemic/pleiotropic effects on extraskeletal target tissues, such as immune and cardiovascular system, pancreatic endocrine cells, muscle, and adipose tissue. Several studies have demonstrated the role of vitamin D supplementation in the prevention/treatment of various autoimmune diseases and improvement of glucose metabolism, muscle, and adipose tissue function. Hence, this review aims to elucidate the effects of vitamin D on extraskeletal target tissues and to investigate the potential therapeutic benefit of vitamin D supplementation among a broad group of pathological conditions, especially with regard to metabolic and autoimmune diseases. In addition, we focused on the best daily intakes and serum levels of vitamin D required for extraskeletal benefits which, even if still controversial, appear to be higher than those widely accepted for skeletal effects.

Medical complications of anorexia nervosa and their treatments: an update on some critical aspects

Anorexia nervosa has the highest mortality rate of any psychiatric disorder. Many of the deaths are attributable to medical complications which arise as the malnutrition and weight loss worsens. Every body system may be adversely affected by anorexia nervosa. Yet, remarkably, most of the medical complications of anorexia nervosa are treatable and reversible with optimal medical care, as part of a multidisciplinary team who are often involved in the care of these patients. Herein, we will describe the medical complications of anorexia nervosa and their treatments.

Influence of a fermented protein-fortified dairy product on serum insulin-like growth factor-I in women with anorexia nervosa: A randomized controlled trial

BACKGROUND & AIMS

Patients with anorexia nervosa (AN) have low serum IGF-I levels that may contribute to a lower bone mineral mass. We investigated the effects of a fermented, protein-fortified, dairy product on serum IGF-I levels in patients with AN during an in-hospital refeeding program.

METHODS

In this multicenter, randomized, double-blind, placebo-controlled, clinical trial conducted at 3 university hospitals and 3 private clinics in France and Switzerland, 62 women recently admitted with confirmed AN and with a baseline low serum IGF-I level were randomized to 2 daily isocaloric fresh cheese pots containing either 15 g/150 g or 3 g/150 g (controls) of protein for 4 weeks. The primary outcome was the change in IGF-I levels.

RESULTS

In the primary intention-to-treat analysis, mean serum IGF-I levels increased during the intervention phase from 22.9 ± 1.5 to 28.6 ± 1.3 nmol/L (means ± SEM) (+20.2%) in the intervention group and from 20.2 ± 1.2 to 25.7 ± 1.5 nmol/L (+16.8%) in controls. In a preplanned analysis of covariance with repeated measures, the between-group difference was close to statistical significance (P = 0.071). In a post-hoc mixed-regression model analysis, the difference was statistically significant (4.9 nmol/l increase; P = 0.003), as was the change of the ratio IGF-I/IGF-BP3 (P=0.004). There was no between-group difference in biochemical markers of bone turnover (osteocalcin, P1NP, CTX) or in serum parathyroid hormone level. Serum calcium levels slightly increased during the intervention phase in the higher protein group (P = 0.02). IGF-BP2 decreased significantly more in the intervention group during the follow up period at week 4 after supplements cessation (P = 0.019).

CONCLUSIONS

Intake of a fermented, protein-fortified, isocaloric dairy product during 4 weeks may slightly increase serum IGF-I levels in women with AN, without significant changes in bone turnover markers.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01823822 (www.clinicaltrials.gov).

Vitamin D status in anorexia nervosa: A meta-analysis

OBJECTIVE

In anorexia nervosa (AN), osteoporosis and osteopenia are common, which have been associated with low circulating levels of vitamin D (VitD) in other settings. We aimed to meta-analyze cross-sectional studies reporting on VitD parameters in patients with AN and healthy controls (HCs).

METHOD

Electronic PubMed search from database inception until December 31, 2013 and meta-analysis of cross-sectional studies comparing serum levels of 25-hydroxyvitamin D (25OH-D), 1,25-dihydroxyvitamin D (1,25OH-D) and dietary VitD between patients with AN and HCs, before or after VitD supplementation. We calculated random effects standardized mean differences (SMDs) ±95% confidence intervals (CIs) as effect size measures.

RESULTS

Out of 1,739 initial hits, 15 studies with a total of 927 participants (AN = 408 and HCs = 519) were meta-analyzed. In the unsupplemented state, both serum 25OH-D (studies = 4; n = 168; SMD = -0.43; 95%CI: -0.83 to -0.03; p = .03) and 1,25OH-D levels (studies = 4; n = 113; SMD = -1.06; 95%CI: -1.47 to -0.66; p < .00001) were significantly lower in AN than HCs. In AN patients treated with cholecalciferol supplementation, serum 25OH-D levels were significantly higher than in HCs (studies = 5; n = 449; SMD = 0.66; 95%CI: 0.01-1.31; p = .05). Paradoxically, despite lower 25OH-D and 1,25OH-D levels, AN patients reported similar intake of VitD compared to HCs (studies = 6; n = 314; SMD = 0.33; 95%CI: -0.16, 0.81; p = .19).

DISCUSSION

Although AN patients reported similar dietary VitD intake compared to HCs, AN patients had significantly lower 25OH-D and 1,25OH-D levels without supplementation. Conversely, supplementation with cholecalciferol fully normalized VitD serum levels. Future studies are needed to clarify the role of VitD supplementation in AN for improving bone health.

Anorexia nervosa - medical complications

In contrast to other mental health disorders, eating disorders have a high prevalence of concomitant medical complications. Specifically, patients suffering from anorexia nervosa (AN) have a litany of medical complications which are commonly present as part of their eating disorders. Almost every body system can be adversely, affected by this state of progressive malnutrition. Moreover, some of the complications can have permanent adverse effects even after there is a successful program of nutritional rehabilitation and weight restoration. Within this article we will review all body systems affected by AN. There is also salient information about both, how to diagnose these medical complications and which are the likely ones to result in permanent sequelae if not diagnosed and addressed early in the course of AN. In a subsequent article, the definitive medical treatment for these complications will be presented in a clinically practical manner.

Nutritional aspects of bone health

Bone mass, geometry and microstructure, and bony tissue material level properties determine bone strength, hence the resistance to fracture. At a given age, all these variables are the consequence of the amount accumulated and of the structure developed during growth, up to the so-called peak bone mass, and of the bone loss and microstructure degradation occurring later in life. Genetic factors primarily contribute to the variance of the determinants of bone strength. Nutritional intakes are environmental factors that influence both processes, either directly by modifying modelling and remodelling, or indirectly through changes in calcitropic hormone secretion and action. Some effects of nutrition on the offspring bone could take place during foetal life. There are interplays between genetic factors, nutritional intakes and physical exercise. Among the nutrients, sufficient dietary intakes of calcium and protein are necessary for bone health in childhood and adolescence as well as later in life.

Bone disease in anorexia nervosa

Anorexia nervosa is a serious psychiatric disorder accompanied by high morbidity and mortality. It is characterized by emaciation due to self-starvation and displays a unique hormonal profile. Alterations in gonadal axis, growth hormone resistance with low insulin-like growth factor I levels, hypercortisolemia and low triiodothyronine levels are almost universally present and constitute an adaptive response to malnutrition. Bone metabolism is likewise affected resulting in low bone mineral density, reduced bone accrual and increased fracture risk. Skeletal deficits often persist even after recovery from the disease with serious implications for future skeletal health. The pathogenetic mechanisms underlying bone disease are quite complicated and treatment is a particularly challenging task.