Anorexia nervosa: slow regain of bone mass

Bone Mineral Density after Weight Gain in 160 Patients with Anorexia Nervosa

Low bone mineral density (BMD) is a frequent complication in anorexia nervosa (AN). There are controversial points of views regarding the restoration of bone mineralization after recovery in AN. We aimed to assess changes of BMD at 3 years in patients with AN and to explore the relationships between body composition, physical activity, and BMD. Patients with AN were included from 2009 to 2011 in a first visit (T0) with evaluation of weight, height, body mass index (BMI), body composition [fat mass (FM) and fat-free mass], and BMD. Those who had low BMD, either osteoporosis or osteopenia, were admitted in a second visit (T1) to carry out a new bone densitometry examination and body composition; they were also asked for their physical activity. At T0, our study involved 160 patients. Low BMD was observed in 53.6% of them and significant factors associated with demineralization were lower BMIs (16.5 ± 2.1 vs 17.3 ± 2.3 kg/m², p = 0.01) and higher duration of AN (11.4 ± 10.5 vs 6.4 ± 6.5 years, p = 0.001). At 3 years follow-up (T1), 42 patients were involved and no significant changes in BMD were observed despite body weight increase (3.8 ± 6.1 kg). Interestingly, FM gain was a significant factor associated with BMD improvement at follow-up (8.0 ± 9.1 vs 3.0 ± 3.5 kg, p = 0.02). Our findings suggest that the restoration of normal bone values is not related to the increase of body weight, at least after 3 years. FM seems to play an important role in the pathophysiological mechanism of osteoporosis and osteopenia in AN.

A systematic review and meta-analysis of the association between eating disorders and bone density

This meta-analysis investigates the effect of an eating disorder on bone mineral density in two eating disorder subtypes. Following conflicting findings in previous literature, this study finds that not only anorexia nervosa, but also bulimia nervosa has a detrimental effect on BMD. Key predictors of this relationship are discussed. This systematic review and meta-analysis investigates bone mineral density (BMD) in individuals with anorexia nervosa (AN) and bulimia nervosa (BN) in comparison to healthy controls (HCs). AN has been associated with low BMD and a risk of fractures and mixed results have been obtained for the relationship between BN and BMD. Deciphering the effect these two ED subtypes on BMD will determine the effect of low body weight (a characteristic of AN) versus the effects of periods of restrictive eating and malnutrition which are common to both AN and BN. We conducted a systematic search through the electronic databases MedLine, EMBASE and PsychInfo and the Cochrane Library to investigate and quantify this relationship. We screened 544 articles and included 27 studies in a random-effect meta-analysis and calculated the standardised mean difference (SMD) in BMD between women with a current diagnosis of AN (n = 785) vs HCs (n = 979) and a current diagnosis of BN (n = 187) vs HCs (n = 350). The outcome measures investigated were spinal, hip, femoral neck and whole body BMD measured by DXA or DPA scanning. A meta-regression investigated the effect of factors including age, duration since diagnosis, duration of amenorrhea and BMI on BMD. The mean BMI of participants was 16.65 kg/m(2) (AN), 21.16 kg/m(2) (BN) and 22.06 kg/m(2) (HC). Spine BMD was lowest in AN subjects (SMD, -3.681; 95 % CI, -4.738, -2.625; p < 0.0001), but also lower in BN subjects compared with HCs (SMD, -0.472; 95 % CI, -0.688, -0.255; p < 0.0001). Hip, whole body and femoral neck BMD were reduced to a statistically significant level in AN but not BN groups. The meta-regression was limited by the number of included studies and did not find any significant predictors. This meta-analysis confirms the association between low BMD and AN and presents a strong argument for assessing BMD not only in patients with AN, but also in patients with BN.

Dual-energy X-ray absorptiometry body composition in patients with secondary osteoporosis

Due to the tight relationship between bone and soft tissues, there has been an increased interest in body composition assessment in patients with secondary osteoporosis as well as other pathological conditions. Dual-energy X-ray absorptiometry (DXA) is primarily devoted to the evaluation of bone mineral status, but continuous scientific advances of body composition software made DXA a rapid and easily available technique to assess body composition in terms of fat mass and lean mass. As a result, the International Society for Clinical Densitometry (ISCD) recently developed Official Positions regarding the use of this technique for body composition analysis. According to ISCD paper, indications are mainly limited to three conditions: HIV patients treated with antiretroviral agents associated with a risk of lipoatrophy; obese patients undergoing treatment for high weight loss; patients with sarcopenia or muscle weakness. Nevertheless, there are several other interesting clinical applications that were not included in the ISCD position paper, such as body composition assessment in patients undergoing organ transplantation, pulmonary disease as well as all those chronic condition that may lead to malnutrition. In conclusion, DXA body composition offers new diagnostic and research possibilities for a variety of diseases; due to its high reproducibility, DXA has also the potential to monitor body composition changes with pharmacological, nutritional or physic therapeutic interventions. ISCD addressed and recommended a list of clinical condition, but the crescent availability of DXA scans and software improvements may open the use of DXA to other indication in the next future. This article provides an overview of DXA body composition indications in the management of secondary osteoporosis and other clinical indications in adults.

Follow-up of bone mineral density and body composition in adolescents with restrictive anorexia nervosa: role of dual-energy X-ray absorptiometry

BACKGROUND/OBJECTIVES

Restrictive Anorexia nervosa (ANR) is an eating disorder (ED) characterized by a low bone mineral content (BMC) and by an alteration in body composition (reduction and abnormal distribution of fat mass-FM and lean mass-LM). The aim of our study was to address whether bone and body composition changes could be influenced by hormonal status and sport in female adolescents with restrictive anorexia nervosa-ANR.

SUBJECTS/METHODS

Prospective study on 79 adolescents with ANR submitted to Dual Energy X-Ray Absorptiometry-DXA at baseline-T0 and after 12 months-T12. Among the 46/79-58.2% patients that completed the study, we evaluated total and regional FM and LM%, as well as lumbar bone mineral density (BMD) and Z-score, linking them to clinical variables: menarche/amenorrhea/hormonal therapy and physical activity.

RESULTS

At T0: body mass index (BMI)=16.4±1.4 kg/m2 with low levels of FM% (21.7±5.7) low BMC in 12/46-26.0% (mean Z-score: -1.21±1.27, with higher values related to physical activity-P=0.001). At T12: a significant increase in BMI-P=0.001, with LM reduction and FM increase (more evident in the trunk-P<0.001); regarding bone, no significant changes were observed, though a tendency in terms of improvement associated with resumption of menses.

CONCLUSIONS

After 1 year, weight recovery was not associated with a reestablishment of bone values; by contrast, it was associated with an increase and a distortion in FM distribution, more evident in trunk region (potential and adjunctive risk factor for the relapse of the psychiatric condition). The complexity of these clinical findings suggested DXA, a low-dose and low-cost technique, in long-term monitoring of ANR patients.

Bone metabolism in anorexia nervosa: molecular pathways and current treatment modalities

Eating disorders are associated with a multitude of metabolic abnormalities which are known to adversely affect bone metabolism and structure. We aimed to comprehensively review the literature on the effects of eating disorders, particularly anorexia nervosa (AN), on bone metabolism, bone mineral density (BMD), and fracture incidence. Furthermore, we aimed to highlight the risk factors and potential management strategies for patients with eating disorders and low BMD. We searched the MEDLINE/OVID (1950-July 2011) and EMBASE (1980-July 2011) databases, focussing on in vitro and in vivo studies of the effects of eating disorders on bone metabolism, bone mineral density, and fracture incidence. Low levels of estrogen, testosterone, dehydroepiandrosterone, insulin-like growth factor-1 (IGF-1), and leptin, and high levels of cortisol, ghrelin, and peptide YY (PYY) are thought to contribute to the 'uncoupling' of bone turnover in patients with active AN, leading to increased bone resorption in comparison to bone formation. Over time, this results in a high prevalence and profound degree of site-specific BMD loss in women with AN, thereby increasing fracture risk. Weight recovery and increasing BMI positively correlate with levels of IGF-1 and leptin, normalisation in the levels of cortisol, as well as markers of bone formation and resorption in both adolescent and adult patients with AN. The only treatments which have shown promise in reversing the BMD loss associated with AN include: physiologic dose transdermal and oral estrogen, recombinant human IGF-1 alone or in combination with the oral contraceptive pill, and bisphosphonate therapy.

Time course of bone loss in patients with anorexia nervosa

OBJECTIVE

To evaluate the time course of bone mineral density (BMD) in women with anorexia nervosa (AN) during 2-year follow-up.

METHOD

We prospectively studied 51 female with AN aged 18-38 years, and 40 age-matched healthy women (19-34 years). BMD was measured in lumbar spine (LS), femoral neck (FN), and total hip (TH) by DXA.

RESULTS

At baseline, weight, body mass index, and lumbar and hip BMD were significantly (p < .001) lower in AN patients than in controls. Patients who gain weight showed a significant increase in BMD at FN (+1.6%; p < .05), and TH (+4.4%; p < .05) and lower nonsignificant changes in LS (+1.3%). Weight at entry, and percent change of weight were significant determinants (p < .05) of the variability in percent change of BMD at FN and TH, whereas weight at entry was the main determinant of bone modifications at lumbar spine.

DISCUSSION

Our data emphasize the influence of weight gain in recovery of bone mass in AN patients, especially at the hip.

Bone mineral density in partially recovered early onset anorexic patients - a follow-up investigation

BACKGROUND AND AIMS

There still is a lack of prospective studies on bone mineral development in patients with a history of early onset Anorexia nervosa (AN). Therefore we assessed associations between bone mass accrual and clinical outcomes in a former clinical sample. In addition to an expected influence of regular physical activity and hormone replacement therapy, we explored correlations with nutritionally dependent hormones.

METHODS

3-9 years (mean 5.2 +/- 1.7) after hospital discharge, we re-investigated 52 female subjects with a history of early onset AN. By means of a standardized approach, we evaluated the general outcome of AN. Moreover, bone mineral content (BMC) and bone mineral density (BMD) as well as lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). In a substudy, we measured the serum concentrations of leptin and insulin-like growth factor-I (IGF-I).

RESULTS

The general outcome of anorexia nervosa was good in 50% of the subjects (BMI >/= 17.5 kg/m2, resumption of menses). Clinical improvement was correlated with BMC and BMD accrual (chi2 = 5.62/chi2 = 6.65, p = 0.06 / p = 0.036). The duration of amenorrhea had a negative correlation with BMD (r = -.362; p < 0.01), but not with BMC. Regular physical activity tended to show a positive effect on bone recovery, but the effect of hormone replacement therapy was not significant. Using age-related standards, the post-discharge sample for the substudy presented IGF-I levels below the 5th percentile. IGF-I serum concentrations corresponded to the general outcome of AN. By contrast, leptin serum concentrations showed great variability. They correlated with BMC and current body composition parameters.

CONCLUSIONS

Our results from the main study indicate a certain adaptability of bone mineral accrual which is dependent on a speedy and ongoing recovery. While leptin levels in the substudy tended to respond immediately to current nutritional status, IGF-I serum concentrations corresponded to the individual's age and general outcome of AN.

Classification of eating disturbance in children and adolescents: proposed changes for the DSM-V

Childhood and adolescence are critical periods of neural development and physical growth. The malnutrition and related medical complications resulting from eating disorders such as anorexia nervosa (AN), bulimia nervosa (BN) and eating disorder not otherwise specified may have more severe and potentially more protracted consequences during youth than during other age periods. The consensus opinion of an international workgroup of experts on the diagnosis and treatment of child and adolescent eating disorders is that (a) lower and more developmentally sensitive thresholds of symptom severity (e.g. lower frequency of purging behaviours, significant deviations from growth curves as indicators of clinical severity) be used as diagnostic boundaries for children and adolescents, (b) behavioural indicators of psychological features of eating disorders be considered even in the absence of direct self-report of such symptoms and (c) multiple informants (e.g. parents) be used to ascertain symptom profiles. Collectively, these recommendations will permit earlier identification and intervention to prevent the exacerbation of eating disorder symptoms.

Bone loss without the loss of bone mineral material? A new perspective on anorexia nervosa

Since the advent on non-invasive in vivo clinical bone densitometry, investigators have reported that regional bone mineral material loss accompanies the onset and continuance of anorexia nervosa (AN). Initial single-energy photon absorptiometric (SPA) studies were followed by a succession of dual-energy X-ray absorptiometric (DXA) investigations, and a few single-energy quantitative computer assisted tomographic (SEQCT) bone densitometry vertebral measurements. Although most all DXA studies found a relatively small diminution (approximately 3%) of bone mineral material at lumbar vertebral and proximal femoral bone-sites of AN-afflicted adolescent girls and young women, these findings have been consensually interpreted and near-universally accepted as losses of actual bone mineral material accompanying AN. It has also been claimed by some that about 50% of those beset by AN while still young adolescents were osteoporotic. Nonetheless, over the last intervening 2 decades of these studies, no specific underlying direct bone-biological causal link between AN and trabecular bone material loss has yet been uncovered. The present exposition shows that in vivo SPA, DXA, and SEQCT measurements of bone mineral material losses do not constitute evidence of actual loss of bone material, and that the attribution of osteopenia and osteoporosis to AN-afflicted younger adolescent girls is not sustainable. Rather, the full gamut of these reported bone material "losses" can be accounted for by the already well-documented AN-induced changes in the anthropometrics and compositional mixes of extra-osseous soft tissues (primarily in a very noticeable reduction of extra-skeletal fat) and intra-osseous bone marrow yellowing (marrow hypoplasia and marrow cell necrosis). These changes in soft tissue compositions and anthropometrics alone have been shown to be sufficient to cause in vivo SPA, DXA, and SEQCT to systematically mis-estimate true bone material density and erroneously register changes in bone mineral content, even when no actual changes in bone mineral material have occurred. As a result, it is seen that in vivo bone densitometry methodologies have not demonstrated that AN induces actual loss of bone mineral material. It is also demonstrated that DXA and SEQCT bone density measurements of predominantly trabecular bone-sites cannot be relied upon as gauges of heightened propensity for early (or late) osteoporotic development.

Factors influencing changes in bone mineral density in patients with anorexia nervosa-related osteoporosis: the effect of hormone replacement therapy

The purpose of this longitudinal study was to evaluate factors affecting changes in bone mineral density (BMD) in patients with anorexia nervosa (AN) and osteoporosis and, more particularly, to assess the benefits of hormone replacement therapy (HRT) on BMD in these patients. Our study involved 45 AN patients, 12 of whom had been treated by HRT for 2 years following a diagnosis of osteoporosis by densitometry (WHO criteria). Patients' mean age was 25.3 +/- 6.7 years. Mean duration of illness was 5.7 +/- 5.3 years. Serum calcium and phosphate were measured at baseline, as were bone remodeling markers. Osteodensitometry by dual-energy X-ray absorptiometry was performed at inclusion and after 2 years. After 2 years, no significant differences were observed between spine, femoral neck, and total hip BMDs either in the HRT group (P = 0.3, P = 0.59, P = 0.58) or in the nontreatment group (P = 0.17, P = 0.68, P = 0.98). Moreover, there were no significant differences between the two groups when changes in spine, femoral neck, and total hip BMDs at 2 years were compared (P = 0.72, P = 0.95, P = 0.58). In both groups, change in weight at 1 year correlated with change in spine BMD at 2 years (r = 0.35, P = 0.04) and change in total-hip BMD at 2 years (r = 0.35, P = 0.04) but not with change in femoral neck BMD at 2 years. Patients with a body mass index (BMI) > or = 17 kg/m(2) at 2 years showed a significant increase in total-hip BMD when compared with patients with a BMI < 17 kg/m(2) (+4.4% +/- 6.7 vs. -0.5% +/- 6.01, P = 0.03). No significant differences were observed for spine and femoral neck BMD. In patients who had recovered their menstrual cycle, significant increases were observed in spine BMD (+4% +/- 6.3 vs. -1.9% +/- 5.6, P = 0.008), femoral neck BMD (+3% +/- 6.2 vs. -2.4% +/- 8, P = 0.05), and total-hip BMD (+3% +/- 7.1 vs. -3.7% +/- 10, P = 0.04). Prevention of bone loss at 2 years in AN patients treated by HRT was not confirmed in this study. We did confirm that increase in weight at 1 year was the most predictive factor for the improvement of spine and hip BMD at 2 years.

Predictors of recovery of ovarian function after weight gain in subjects with amenorrhea related to restrictive eating disorders

OBJECTIVE

The aim of the present study was to investigate the anthropometric and endocrine characteristics of subjects with amenorrhea related to eating disorders after weight recovery, in order to identify factors connected with the resumption of menses.

METHODS

Clinical data, body composition parameters and serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, cortisol, leptin and insulin were assessed in two groups of young women classified according to menstrual status after weight rehabilitation: 43 subjects who displayed persistent amenorrhea and 34 who resumed menses. Univariate and multivariate logistic regression analyses were used to examine the relationships between the different parameters and menstrual recovery.

RESULTS

The patients who resumed menses had low initial weight and BMI, and a greater difference between current and initial BMI (DeltaBMI), than those with amenorrhea. No differences were observed in lean mass, body fat or bone density between the two groups. Moreover, the reduction in FSH and the increase in LH, insulin and leptin emerged as significant predictors of menstrual recovery. Increased DeltaBMI and insulin continued to be positive predictors in the multivariate analysis.

CONCLUSION

Following weight rehabilitation, the individual's metabolic set point before weight loss and the current insulin levels appear significant in predicting the reactivation of reproductive function.

Evaluation of bone loss and its mechanisms in anorexia nervosa

The purpose of this cross-sectional study was to assess the extent of and mechanisms involved in bone loss in anorexia nervosa patients. We compared 113 anorexia nervosa patients (mean age 25 +/- 8 years, mean duration of disease 5.7 +/- 6.1 years) with 21 age-matched controls. Mean duration of amenorrhea was 3.2 +/- 4.7 years. We measured serum calcium and phosphate; bone remodeling markers (osteocalcin, bone-specific alkaline phosphatase [BSAP], serum crosslaps [CTX], and carboxyl-terminal telopeptide of type I collagen [ICTP]); follicle-stimulating hormone and luteinizing hormone levels; and estradiol (ultrasensitive assay), cortisol, urinary free cortisol, thyroid function, prolactin, and nutritional factors (insulin-like growth factor I [IGF-I], IGF binding protein 3 [IGFBP3]). In controls, only bone remodeling markers and nutritional factors were measured. Osteodensitometry was also performed on both patients and controls. Weight and body mass index (BMI) were significantly lower in anorexia nervosa patients than in controls (P < 0.0001). No significant differences were observed in biological indicators except for IGF-I, which was lower in anorexia nervosa patients (0.9 +/- 0.4 UI/mL) than in controls (1.5 +/- 0.4 UI/mL) (P < 0.0001). Densitometric measurements at three sites were significantly lower in anorexia nervosa patients and correlated with duration of disease and amenorrhea and with IGF-I at the hip only (P < 0.01). In the study population, osteoporosis was observed in 24 patients (21%) and osteopenia in 54 patients (48%). Patients with osteoporosis were significantly older and had longer disease and amenorrhea durations; lower weight and BMI; higher alkaline phosphatase, BSAP, and osteocalcin; and lower serum ICTP, IGF-I, and IGFBP3. All of these differences were significant and remained so even after multiple adjustments were made, except for IGF-I (P = 0.21). When multivariate analysis was performed, we found that age at onset of amenorrhea, weight, alkaline phosphatase, urinary free cortisol, and serum estradiol concentration accounted for 54% of the variance in spinal bone mineral density (BMD). Duration of amenorrhea, alkaline phosphatase, and weight explained 46.6% of the variance in femoral neck BMD. Duration of amenorrhea, IGF-I, and ICTP levels accounted for 38.6% of the variance observed in total hip BMD. The etiology of bone loss in patients with anorexia nervosa is multifactorial. Hypoestrogenia alone cannot account for this loss, and nutritional factors, IGF-I concentrations in particular, seem to play an important role.

Marked increases in bone mineral density and biochemical markers of bone turnover in patients with anorexia nervosa gaining weight

Anorexia nervosa (AN) is a life-threatening eating disorder characterized by an inability to maintain a normal body weight and amenorrhoea, often associated with osteoporosis and increased risk of fragility fractures. Bone metabolism, including markers of bone turnover (serum total alkaline phosphatase, bone alkaline phosphatase [bone AP], osteocalcin [OC] and type I collagen C-telopeptide breakdown products [sCTX]) and bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) at the spine and at the hip, were evaluated in 55 consecutive women with AN undergoing a 3-month intensive nutritional rehabilitation program. The control group was constituted of 25 healthy young medical students. In AN patients body weight increased during the 3-month nutritional program from 37.8+/-5.1 (mean+/-SD) to 51.5+/-4.5 kg. The corresponding BMI rose to values >17.5 kg/m(2) in all patients. Mean BMD significantly rose by 2.6+/-3.5% and 1.1+/-3.6% at the hip and at the spine, respectively. The markers of bone formation, serum bone AP and osteocalcin, significantly rose by two-folds, while sCTX decreased by 16%. The changes in hip BMD were positively related (p<0.005) to changes in body weight and in bone AP (p<0.02) while the changes in spine BMD were positively related to changes in serum osteocalcin (p<0.05). In the 25 patients who attended the 12-month posttreatment control, mean body weight significantly decreased by 3.6+/-6.0 kg and this was not associated with any significant change in BMD values. In the patients in whom BMI fell again below 17.5 kg/m(2) hip BMD values decreased significantly. On the contrary, in the patients who maintained BMI >17.5 kg/m(2), BMD values continued to rise up to values over the 15-month observation of 4.8+/-6.2 and 7.1+/-12.1 at the spine and hip, respectively. In conclusion, we have demonstrated that substantial gains in weight in women with chronic AN are associated with remarkable increases in BMD at both the hip and the spine. If weight is maintained, the overall improvement approach 1 SD within 1 year. The changes in both weight and BMD are correlated with improvements in bone formation markers and diminutions in a marker of bone resorption.

Open Issues in Anorexia Nervosa: Prevention and Therapy of Bone Loss

Anorexia nervosa and diet-induced amenorrhea have an important impact not only on gynecological health but also on bone mass, especially if the disease is not promptly recognized and treated. This is particularly important because these conditions usually arise in adolescence, when peak bone mass is normally achieved. In this article we discuss the therapeutic issues related to bone loss associated with eating disorders.

Determinants of skeletal loss and recovery in anorexia nervosa

CONTEXT

Anorexia nervosa (AN) is complicated by severe bone loss. The effects of persistent undernutrition and consequent neuroendocrine dysfunction on bone mass and the factors influencing skeletal recovery have not been well characterized.

OBJECTIVE

The objective of the study was to determine the rate of bone loss at the spine and hip in women with AN and whether resumption of menstrual function and/or improvement in weight are determinants of skeletal recovery in AN.

DESIGN

The study had a longitudinal design.

SETTING

The study was conducted at a clinical research center.

STUDY PARTICIPANTS

Participants included 75 ambulatory women with AN.

MAIN OUTCOME MEASURES

Bone mineral density (BMD) and body composition were measured with dual x-ray absorptiometry.

RESULTS

In women not receiving oral contraceptives, those who did not improve weight or resume menses had a mean annual rate of decline of 2.6% at the spine and 2.4% at the hip. Those who resumed menses and improved weight had a mean annual increase of 3.1% at the posteroanterior spine and 1.8% at the hip. Women who recovered menses demonstrated a mean increase of posteroanterior spine but not hip BMD, independent of weight gain. Women who improved weight, regardless of whether they recovered menstrual function, demonstrated a mean increase of hip, but not spine, BMD. Increase in fat-free mass was a more significant determinant of increased BMD than weight or fat mass gain. In women receiving oral contraceptives, there was no increase in BMD at any site despite a mean 11.7% weight increase.

CONCLUSIONS

These data suggest that rapid bone loss, at an average annual rate of about 2.5%, occurs in young women with active AN. Resumption of menstrual function is important for spine BMD recovery, whereas weight gain is critical for hip BMD recovery. We did not observe an increase in BMD with weight gain in women receiving oral contraceptives. Therefore, improvements in reproduction function and weight, with increases in lean body mass a critical component, are both necessary for skeletal recovery in women with AN.

Normalization of bone density in a previously amenorrheic runner with osteoporosis

PURPOSE

To examine changes in bone mineral density (BMD) and bone mineral content (BMC) in relation to pharmacological and nutritional interventions in a distance runner diagnosed with the female athlete triad of disordered eating, amenorrhea, and osteoporosis.

METHODS

BMD of the lumbar spine (L2-L4) and total proximal femur were measured from ages 22.9 to 30.8 yr using dual x-ray absorptiometry (DXA).

RESULTS

At age 22.9, the patient presented with primary amenorrhea, low body weight (BMI: 15.8 kg.m(-2)), and low BMD in the spine (74% of normal, T score: -2.50) and hip (80% of normal, T score: -1.54). For the next 2 yr, the patient took oral contraceptives to induce menses, but continued to maintain a low weight. Her BMD remained unchanged. At age 25.1 yr, she decided to gain weight and improve her nutrition, resulting in small increases in spinal BMD (+1.1%), hip BMD (+1.6%), and total body BMC (+7.6%) in 4 months. From ages 25.4 to 30.8 yr, the patient continued to gain weight, eventually reaching a healthy BMI of 21.3 kg.m(-2); correspondingly, since baseline, her BMD had increased 25.5% in the spine and 19.5% in the hip, bringing her BMD to within normal values (spine: 94% of normal, hip: 96% of normal).

CONCLUSION

This case illustrates that even if skeletal development is interrupted in adolescence, there is still the potential for "catch-up" in BMD well into the third decade of life. Reversal of large bone density deficits in this patient can be attributed to improved nutrition and weight gain but not to hormone replacement.

Changes in bone mineral density, body composition and biochemical markers of bone turnover during weight gain in adolescents with severe anorexia nervosa: a 1-year prospective study

Osteoporosis is a serious complication of anorexia nervosa and in affected adolescents may result in a permanent deficit in bone mass. The pathophysiology of this bone disease has not been clearly defined. In this prospective study of 26 young women with anorexia nervosa aged 13-20 years (mean 16.5) we have measured changes in bone mineral density, total body composition and biochemical indices of bone turnover over 1 year. Over this period there was a mean weight gain of 10 kg and significant height gain with baseline and final values for body mass index of 14.2+/-1.7 and 17.6+/-2.3 kg/m2 (P<0.001). However, no significant changes were seen in bone mineral density in the spine or proximal femur during the study; total body bone mineral content was significantly higher than baseline at 3 months and 12 months (P=0.001 and P<0.0001), but total body bone mineral density at 3 months was significantly lower than baseline (P=0.003). Serum osteocalcin and bone-specific alkaline phosphatase values increased significantly and remained higher than baseline at all time points whereas urinary NTX/creatinine excretion showed a non-significant increase over the first 6 months of the study, but at 12 months, the mean value was significantly lower than baseline. Mean serum 25-hydroxyvitamin D levels showed a significant decrease at 6 months (P<0.05), but returned towards baseline thereafter. There was a significant increase in serum parathyroid hormone levels at all time points compared to baseline, these occurring within the normal range. These results indicate that although weight gain in young anorexics is associated with linear growth, bone mineral density does not increase. Whether this deficit can be corrected subsequently requires longer-term prospective studies.

Bone mineral density in relation to body mass index among young women: a prospective cohort study

AIM

To identify important predictors among lifestyle behaviours and physiological factors of bone mineral density (BMD) in relation to body mass index (BMI) among young women over a 2-year period. DESIGN, SAMPLE AND MEASUREMENTS: Data were collected in 1999 and 2001. Healthy young women (n=152) completed a questionnaire. BMD measurements were performed by DEXA in the calcaneus. The women were subdivided into three categories according to baseline BMI.

RESULTS

Baseline bodyweight explained 25% of the variability in BMD at follow-up in the BMI<19 category, and high physical activity seemed to hinder BMD development. In the BMI>24 category, a difference in time spent outdoors during winter between baseline and follow-up was the single most important factor for BMD levels. Overweight women with periods of amenorrhoea had lower BMD than overweight women without such periods.

CONCLUSIONS

Predictors and lifestyle behaviours associated with BMD are likely to be based on women of normal weight. BMI should be considered when advising on physical activity, since high physical activity seems to impair BMD development among underweight young women, possibly due to energy imbalance. Among overweight women, sleep satisfaction is the greatest predictor associated with BMD change and may indicate better bone formation conditions. Energy balance and sleep quality may be prerequisites of bone health and should be considered in prevention.

A prospective study of changes in bone turnover and bone density associated with regaining weight in women with anorexia nervosa

Anorexia nervosa (AN) is a condition of self-induced weight loss, associated with an intense fear of gaining weight. Previous studies have shown that bone density may increase with regaining and maintaining normal weight; however, relatively little is known about the changes in bone metabolism that occur during weight restoration. We describe the effect of weight restoration and maintenance of weight over 1 year on bone mineral density (BMD) and bone turnover. We recruited women from the eating disorders services at the South West London and St George's Mental Health NHS Trust, and the Priory and Charter Nightingale Hospitals in London, UK. Details of their AN, fracture history, menstrual history and exercise were obtained by interview and case note review. Morning samples of blood and second void urine were taken for biochemical analysis. BMD was measured by DXA at the lumbar spine (LS), femoral neck (FN), distal radius (RD) and total body bone mineral content (BMC). Patients then entered the treatment program, which includes re-feeding, dietary education and psychotherapy. Over a period of 42 months, we recruited 55 women who agreed to participate in this study and underwent baseline investigations. Of these, 15 (27%) subjects achieved and then maintained their target weight for the duration of the study. At baseline for all subjects (n=55) estradiol levels were lower than the normal reference ranges (both follicular and luteal phases) in 91% of the women. Bone specific alkaline phosphatase (BSAP) concentrations were lower than the premenopausal reference range in 55% of women, and urinary deoxypyridinoline (DPD) was above the premenopausal reference range in 78% of women. Baseline lumbar spine BMD was positively related to BMI (Pearson's r=0.29, P=0.04) and inversely related to bone turnover markers: urinary DPD (Pearson's r=-0.39, P=0.01 and serum BSAP (Pearson's r=-0.3, P=0.06). The 15 patients who regained and maintained weight were followed-up for a mean duration of 69 weeks (SD 7.3, range 54 to 84 weeks). Mean BMI increased from 14.2 (1.7) to 20.2 (0.77) kg/m2 and remained stable throughout follow-up. Menstruation resumed in 8 of the 15 women. Total body BMC and LS BMD increased significantly over the duration of follow-up (by 4.3% each), but FN BMD and distal radius remained stable. Lumbar spine bone area also increased significantly, whereas FN and distal radius did not. These changes were associated with a significant increase in BSAP (P=0.01), and a non-significant trend for a decrease in DPD (P=0.10). Our findings suggest that when women are at low body weight they are in a hypo-estrogenic state, which is associated with imbalance of bone turnover (high bone resorption and low bone formation). This is reversed with weight gain and persists as target weight is maintained and is associated with increases in BMC and BMD.

Bone loss associated with anorexia nervosa

The objective of this study was to evaluate the epidemiology, diagnosis, pathophysiology, and treatment of bone loss related to anorexia nervosa. Earlier onset and longer duration of anorexia nervosa are associated with more severe bone loss. Osteoporosis develops in 38-50% of cases. Bone mineral density measurement by dual-energy X-ray absorptiometry is useful for assessing bone mass, and bone marker assays provide information on bone turnover. Bone loss in anorexia nervosa is probably multifactorial. Estrogen deficiency was long felt to be the major factor. However, in contrast to postmenopausal osteoporosis, bone loss associated with anorexia nervosa is related mainly to inadequate bone formation, with only a slight increase in bone resorption. This suggests a role for nutritional factors, such as disturbances in the growth hormone-somatomedin C axis (GH/IGF-I) related to malnutrition. The best treatment strategy for correcting bone mass in patients with anorexia nervosa is not agreed on. Resumption of menstrual cycles and weight gain seem necessary but not always sufficient. Studies found no benefits with estrogen therapy, but this was usually given as estrogen-progestin contraceptives. No vast studies evaluating hormone replacement therapy have been reported. Bone formation enhancers such as IGF-I seem to provide the best results, most notably when used in combination with estrogens. This suggests that complex treatment strategies combining bone formation enhancers and bone resorption inhibitors may deserve evaluation.

Body mass index and disease duration are predictors of disturbed bone turnover in anorexia nervosa. A case-control study

OBJECTIVE

To characterize the influence of body mass index (BMI), body composition, hormonal factors and disease duration on bone metabolism markers in anorexia nervosa (AN) patients.

DESIGN

Case-control study with 51 AN patients and 51 controls matched for age, sex and body height. Assessment of anthropometric and bioimpedance data, and of biochemical serum parameters and of oral contraceptives use.

RESULTS

Patients had a lower BMI, lower fat mass, lower fat-free mass and lower muscle mass (MM) compared to the controls (all P values <0.001). Moreover, serum levels of osteocalcin (bone formation marker) were lower while serum C-telopeptide concentrations (CTx; bone resorption marker) and the CTx/osteocalcin ratio (an index reflecting the balance of bone remodeling) were higher in the AN patients compared to the controls (P<0.01-0.001). In addition, patients had enhanced serum calcium and cortisol levels and reduced serum levels of thyroid hormones, insulin, and leptin (P values <0.05-0.001). Mean disease duration was 91+/-13 months. In a multiple regression analysis, BMI (P<0.0001), MM (P<0.005) and duration of the disease (P<0.005) were independent predictors of the CTx/osteocalcin ratio in the AN patients. There was a nonlinear association between BMI and the CTx/osteocalcin ratio of r=-0.72 (P<0.001) in the AN patients, but only a weak relation of r=-0.27 (P<0.05) between these parameters in the control subjects. Use of oral contraceptives had no effect on the CTx/osteocalcin ratio, neither in AN patients nor in controls.

CONCLUSIONS

Data indicate an uncoupling of bone formation and bone resorption in AN, which is primarily the result of a low BMI and influenced by the duration of the disease.

Patients With Eating Disorders

PURPOSE

To analyze fracture risk and bone mineral density in patients with eating disorders (anorexia nervosa, bulimia nervosa, and other eating disorders).

DESIGN

Clinical overview.

FINDINGS

Bone mineral density is decreased and fracture risk increased in patients with anorexia nervosa. In patients with bulimia nervosa, bone mineral is only marginally decreased and fracture risk marginally increased. In patients with other eating disorders (eating disorders not otherwise specified), bone mineral density is decreased and fracture risk increased.

CONCLUSIONS

Fracture risk is increased in patients with eating disorders. An eating disorder should be suspected in severely underweight young individuals (primarily girls) presenting with fractures, especially low-energy fractures.

Influence of smoking and oral contraceptives on bone mineral density and bone remodeling in young women: a 2-year study

The objective of the study was to explore the influence of menstrual irregularities, oral contraceptives and smoking on bone mineral density (BMD) development and bone turnover with time. Healthy young women (n = 118) were divided into four categories: (a) women neither smoking nor using oral contraceptives; (b) women who were smokers; (c) women using oral contraceptives; (d) women who were smoking and using oral contraceptives. They responded to a validated questionnaire with 34 questions concerning lifestyle and the Sense of Coherence scale (SOC). BMD was measured by dual energy x-ray absorptiometry (DEXA). Deoxypyridinoline (DPD) was measured in urine. Data were analyzed by multiple linear regression analysis. Among smokers, BMD level decreased during a 2-year period and smoking was associated with a larger negative change in BMD. Use of oral contraceptives moderated the negative impact of smoking. Women using oral contraceptives at baseline and with regular bleeding induced by contraceptive pills had a significantly higher BMD at baseline and at follow-up. They also had lower SOC than women who had natural regular bleedings. Use of oral contraceptives in combination with smoking was linked to high alcohol consumption and higher frequency of self-reported body weight reduction, which reduced the negative BMD change in this category. DPD level and difference were strongly associated with estrogen influence. It is concluded that smokers without OCs had a negative BMD development and BMD in young women with irregular menstruations seems to be improved by OC.

Bone resorption in anorexia nervosa and rehabilitated patients

OBJECTIVE

To assess the impact of anorexia nervosa and that of nutritional rehabilitation on bone resorption.

DESIGN

Cross-sectional, observational study.

SETTING

Rome, Italy

SUBJECTS

Twenty-eight female patients affected by anorexia nervosa (AN, BMI<or=17.0 kg/m(2)), 18 females rehabilitated from anorexia nervosa and weight-stable for at least 6 months (RE, BMI >or=18.5 kg/m(2)) and 34 age- and sex-matched healthy controls (CO, BMI >or=18.5 kg/m(2)). Among AN patients, 16 were affected by the 'restrictive' (ANr) and 12 by the 'purging' type (ANp) of anorexia nervosa.

METHOD

Body weight, height and skeletal diameters were measured on each individual. The skeletal mass (SKM) was predicted from the skeletal diameters of the elbow, wrist, knee and ankle, using the equation of Martin. Twenty-four-hour urinary excretion of pyridinium crosslinks of collagen (pyridinoline (Pyd) and deoxypyridinoline (Dpd)) and creatinine was assessed by reversed-phase HPLC with fluorimetric detection after solid-phase extraction and by the Jaffé-method with deproteinization, respectively.

RESULTS

Twenty-four-hour urinary output of Pyd and Dpd was not significantly different between AN and CO when expressed in absolute values, but AN showed higher bone resorption than CO when Pyd and Dpd excretion was adjusted by either creatinine (P<0.0000) or the SKM (P<0.05). Within the AN group, urinary excretion of both cross-links was significantly and consistently higher in ANp compared with ANr (P<0.05). However, these differences disappeared when crosslink output was adjusted either by urinary creatinine or SKM. RE subjects showed no differences in bone resorption with the AN group despite weight gain, being crosslink excretion consistently elevated compared to controls (Pyd: P<0.01 by creatinine and P<0.05 by SKM; Dpd: P<0.01 by creatinine and P<0.05 by SKM).

CONCLUSION

Bone resorption is elevated in anorexia nervosa and different strategies for low-weight maintenance do not seem to have a differential impact. Increased bone resorption persists in subjects with past diagnosis of anorexia nervosa despite rehabilitation lasting more than 6 months. This finding indicates that bone mass and turnover should be monitored in anorexia nervosa patients and ex-patients well beyond recovery of normal body mass. Further investigation is warranted to examine the long-term effect of such prolonged increase in bone turnover at a young age.

Fractures in patients with anorexia nervosa, bulimia nervosa, and other eating disorders--a nationwide register study

OBJECTIVE

To study fracture risk in patients with anorexia nervosa (AN), bulimia nervosa (BN), or eating disorders not otherwise specified (EDNOS).

METHOD

Cohort study including all Danes diagnosed with AN (n = 2,149), BN (n = 1,294), or EDNOS (n = 942) between 1977 and 1998. Each patient was compared with three randomly drawn age- and gender-matched control subjects.

RESULTS

Fracture risk was increased in AN after diagnosis compared to controls (incidence rate ratio: 1.98, 95% CI: 1.60-2.44), but not before. The increased fracture risk persisted more than 10 years after diagnosis. A significant increase in fracture risk was found before diagnosis in BN (1.31, 95% CI: 1.04-1.64), with a trend towards an increase after diagnosis (1.44, 95% CI: 0.93-2.22). EDNOS patients had a significant increase in fracture risk before (1.39, 95% CI: 1.06-1.81) and after diagnosis (1.77, 95% CI: 1.25-2.51).

DISCUSSION

The increased fracture risk many years after diagnosis indicates permanent skeletal damage.

Adolescent anorexia nervosa: the catch-up effect in bone mineral density after recovery

OBJECTIVE

To determine whether bone mineral density (BMD) loss can be reversed in adolescent anorexic patients.

METHOD

A prospective study with 108 anorexia nervosa patients (DSM-IV) from 12 to 17 years of age at the Eating Disorders Unit in the Hospital Clinic of Barcelona (Spain). They were first evaluated by dual-energy x-ray absorptiometry in lumbar spine and femoral neck consecutively from 1997 until 1999 and reexamined after 6 to 30 months. Results were compared with normative values of bone mass.

RESULTS

Patients with poor outcome (n = 44) had a bone mass loss. Patients with good short-term outcome were divided in two groups. The group with normal BMD at first evaluation (n = 41) had a bone mass gain per year of 3.0% at lumbar spine and 0.5% at femoral neck. The group with low BMD at first evaluation (n = 23) had an increase per year of 9.1% at lumbar spine and 4.5% at femoral neck. In a multiple linear regression analysis with the variables body mass index, age, months with menstruation, and BMD zscore at first evaluation, the only predictor of BMD increase was the first z score both at the lumbar spine (coefficient R = 0.64; p < .001) and at the femoral neck (coefficient R = 0.5; p < .001).

CONCLUSIONS

There is a catch-up effect in adolescent patients with low BMD but good short-term outcome.

On exposure to anorexia nervosa, the temporal variation in axial and appendicular skeletal development predisposes to site-specific deficits in bone size and density: a cross-sectional study

Skeletal development is heterogeneous. Throughout growth, bone size is more maturationally advanced than the mineral being accrued within its periosteal envelope; before puberty, appendicular growth is more rapid than axial growth; during puberty, appendicular growth slows and axial growth accelerates. We studied women with differing age of onset of anorexia nervosa to determine whether this temporal heterogeneity in growth predisposed to the development of deficits in bone size and volumetric bone mineral density (vBMD), which varied by site and severity depending on the age at which anorexia nervosa occurred. Bone size and vBMD of the third lumbar vertebra and femoral neck were measured using dual-energy X-ray absorptiometry in 210 women aged 21 years (range, 12-40 years) with anorexia nervosa. Results were expressed as age-specific SDs (mean +/- SEM). Bone width depended on the age of onset of anorexia nervosa; when the onset of anorexia nervosa occurred (1) before 15 years of age, deficits in vertebral body and femoral neck width did not differ (-0.77+/-0.27 SD and -0.55+/-0.17 SD, respectively); (2) between 15 and 19 years of age, deficits in vertebral body width (-0.95+/-0.16 SD) were three times the deficits in femoral neck width (-0.28+/-0.14 SD; p < 0.05 comparing the deficits), (3) after 19 years of age, deficits in the vertebral body width (-0.49+/-0.26 SD; p = 0.05) were half that in women with earlier onset of anorexia nervosa. No deficit in bone width was observed at the femoral neck. Deficits in vBMD at the vertebra and femoral neck were independent of the age of onset of anorexia nervosa but increased as the duration of anorexia nervosa increased, being about 0.5 SD lower at the vertebra than femoral neck. We infer that the maturational development of a region at the time of exposure to disease, and disease duration, determine the site, magnitude, and type of trait deficit in anorexia nervosa. Bone fragility due to reduced bone size and reduced vBMD in adulthood is partly established during growth.