Predictors of osteopenia in premenopausal women with anorexia nervosa

Exercise Degrades Bone in Caloric Restriction, Despite Suppression of Marrow Adipose Tissue (MAT)

Marrow adipose tissue (MAT) and its relevance to skeletal health during caloric restriction (CR) is unknown: It remains unclear whether exercise, which is anabolic to bone in a calorie-replete state, alters bone or MAT in CR. We hypothesized that response of bone and MAT to exercise in CR differs from the calorie-replete state. Ten-week-old female B6 mice fed a regular diet (RD) or 30% CR diet were allocated to sedentary (RD, CR, n = 10/group) or running exercise (RD-E, CR-E, n = 7/group). After 6 weeks, CR mice weighed 20% less than RD, p < 0.001; exercise did not affect weight. Femoral bone volume (BV) via 3D MRI was 20% lower in CR versus RD (p < 0.0001). CR was associated with decreased bone by μCT: Tb.Th was 16% less in CR versus RD, p < 0.003, Ct.Th was 5% less, p < 0.07. In CR-E, Tb.Th was 40% less than RD-E, p < 0.0001. Exercise increased Tb.Th in RD (+23% RD-E versus RD, p < 0.003) but failed to do so in CR. Cortical porosity increased after exercise in CR (+28%, p = 0.04), suggesting exercise during CR is deleterious to bone. In terms of bone fat, metaphyseal MAT/ BV rose 159% in CR versus RD, p = 0.003 via 3D MRI. Exercise decreased MAT/BV by 52% in RD, p < 0.05, and also suppressed MAT in CR (-121%, p = 0.047). Histomorphometric analysis of adipocyte area correlated with MAT by MRI (R2 = 0.6233, p < 0.0001). With respect to bone, TRAP and Sost mRNA were reduced in CR. Intriguingly, the repressed Sost in CR rose with exercise and may underlie the failure of CR-bone quantity to increase in response to exercise. Notably, CD36, a marker of fatty acid uptake, rose 4088% in CR (p < 0.01 versus RD), suggesting that basal increases in MAT during calorie restriction serve to supply local energy needs and are depleted during exercise with a negative impact on bone. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

The prevalence of osteoporosis in an older population with very high body mass index: evidence for an association

BACKGROUND

Studies have demonstrated the beneficial effect of normal and high body mass index (BMI) upon risk of osteoporosis (OP). No study has investigated the prevalence of OP in an older population with a very high BMI (higher than 40 kg/m(2) ).

METHODS

Data of patients aged over 50 years that attended for a dual energy X-ray absorptiometry scan at a UK district general hospital were collated. The population was divided according to BMI increments of 5 kg/m(2) . The prevalence of OP for each BMI category was ascertained. Logistic regression analysis was used to investigate for significant associations between BMI and OP prevalence, adjusted for age, sex and number of OP risk factors.

RESULTS

Data of 10,796 study subjects were collated. Mean age was 67.34 years. Decreasing prevalence of OP was associated with increasing BMI up to 40 kg/m(2) , above which increasing BMI was associated with increasing prevalence of OP.

CONCLUSIONS

The protective effect of increasing BMI exists up to 40 kg/m(2) . A BMI higher than 40 kg/m(2) is associated with increased prevalence of OP. This finding may be attributable to reduced level of bone weight bearing in individuals with a very high BMI.

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.

Exercise interventions for women with anorexia nervosa: a review of the literature

OBJECTIVE

To identify exercise interventions in the empirical literature to help inform clinical decision making in the treatment of underweight individuals with anorexia nervosa (AN) and review any recommended differences in treatment planning for those who excessively exercise and those who do not.

METHOD

Online search engines and cross-referencing articles identified relevant studies.

RESULTS

Six exercise interventions in clinical settings were reviewed, including three conducted in hospitals. A few studies provided some evidence to support the implementation of moderate physical activity during treatment. Most did not include specific exercise program descriptions. Patient eligibility varied from obligatory for all patients to programs that specified weight requirements.

DISCUSSION

Few studies have systematically explored exercise as a part of treatment among patients with AN. Findings of the current review suggest a need for developing further research, but currently the field may benefit from standardized guidelines for treating excessive exercisers with AN.

Effects of exercise on bone mass in young women with anorexia nervosa

PURPOSE

The response of bone to exercise in women with anorexia nervosa (AN) is unclear. We investigated the associations between bone mineral density (BMD) and exercise performed while ill and while recovered in women with a history of AN.

METHODS

A cross-sectional study was conducted with 141 women with AN (85 ill; 56 recovered), aged 17-40 yr. BMD at the lumbar spine (LS), femoral neck (FN), and total body (TB) was measured by dual-energy x-ray absorptiometry. Life History Calendar and Minnesota Leisure Time Physical Activity interviews were used to collect lifetime illness and exercise histories (amount and bone loading type). Average hours per week of each of moderate (MOD) and high (HI) bone loading exercise were determined for three illness phases: "before ill," "while ill," and "while recovered." Participants were categorized into four exercise groups for each phase: MOD-ONLY, HI-ONLY, BOTH, and NEITHER (reference group). Weight-adjusted BMD z-scores were compared in the exercise groups by multivariable linear regression, adjusting for illness duration and severity, and exercise during the other illness phases.

RESULTS

In ill participants, MOD-ONLY "while ill" had lower BMD at LS (β = -0.69, 95% confidence interval (CI) = -1.02 to -0.05) and TB (β = -0.73, 95% CI = -1.31 to -0.15) than the NEITHER group. In recovered participants, HI-ONLY "while recovered" had higher BMD at FN (β = 0.95, 95% CI = 0.15-1.75) and TB (β = 0.79, 95% CI = 0.07-1.51) than the NEITHER group.

CONCLUSIONS

The effect of exercise on bone in AN patients is dependent on both the type of mechanical loading and the phase of illness during which it was performed. Excessive moderate loading exercise while ill may put patients at higher risk of low bone mass, but high bone loading activities may provoke bone accrual during recovery.

Use of SSRIs may Impact Bone Density in Adolescent and Young Women with Anorexia Nervosa

OBJECTIVES

Alterations in serotonin impact bone metabolism in animal models, and selective serotonin reuptake inhibitors (SSRI) have been associated with increased fracture risk in older adults. SSRIs are commonly used in anorexia nervosa (AN), a condition that predisposes to low bone mineral density (BMD). Our objective was to determine whether SSRI use is associated with low BMD in AN.

METHODS

We examined Z-scores for spine, hip and whole body (WB) BMD, spine bone mineral apparent density and WBBMC/height (Ht) in females with AN 12-21 years old who had never been on SSRIs, on SSRIs for <6 months (<6M) or >6 months (>6M).

RESULTS

Subjects on SSRIs for >6M had lower spine, femoral-neck and WBBMD Z-scores than those on SSRIs for <6M. Hip BMD and WBBMC/Ht Z-scores were lowest in subjects on SSRIs for >6M. Duration of SSRI use, duration since AN diagnosis and duration of amenorrhea inversely predicted BMD, whereas BMI was a positive predictor. In a regression model, duration of SSRI use remained an independent negative predictor of BMD.

DISCUSSION

Duration of SSRI use >6M is associated with low BMD in AN.

CONCLUSION

It may be necessary to monitor BMD more rigorously when duration of SSRI use exceeds 6M.

Association of macrophage inhibitory cytokine-1 with nutritional status, body composition and bone mineral density in patients with anorexia nervosa: the influence of partial realimentation

Background

Macrophage inhibitory cytokine-1 (MIC-1) is a key inducer of cancer-related anorexia and weight loss. However, its possible role in the etiopathogenesis of nutritional disorders of other etiology such as anorexia nervosa (AN) is currently unknown.

Methods

We measured fasting serum concentrations of MIC-1 in patients with AN before and after 2-month nutritional treatment and explored its relationship with nutritional status, metabolic and biochemical parameters. Sixteen previously untreated women with AN and twenty-five normal-weight age-matched control women participated in the study. We measured serum concentrations of MIC-1 and leptin by ELISA, free fatty acids by enzymatic colorimetric assay, and biochemical parameters by standard laboratory methods; determined resting energy expenditure by indirect calorimetry; and assessed bone mineral density and body fat content by dual-energy X-ray absorptiometry. ANOVA, unpaired t-test or Mann-Whitney test were used for groups comparison as appropriate. The comparisons of serum MIC-1 levels and other studied parameters in patients with AN before and after partial realimentation were assessed by paired t-test or Wilcoxon Signed Rank Test as appropriate.

Results

At baseline, fasting serum MIC-1 concentrations were significantly higher in patients with AN relative to controls. Partial realimentation significantly reduced serum MIC-1 concentrations in patients with AN but it still remained significantly higher compared to control group. In AN group, serum MIC-1 was inversely related to Buzby nutritional risk index, serum insulin-like growth factor-1, serum glucose, serum total protein, serum albumin, and lumbar bone mineral density and it significantly positively correlated with the duration of AN and age.

Conclusions

MIC-1 concentrations in AN patients are significantly higher relative to healthy women. Partial realimentation significantly decreased MIC-1 concentration in AN group. Clinical significance of these findings needs to be further clarified.

Growth hormone, insulin-like growth factors, and the skeleton

GH and IGF-I are important regulators of bone homeostasis and are central to the achievement of normal longitudinal bone growth and bone mass. Although GH may act directly on skeletal cells, most of its effects are mediated by IGF-I, which is present in the systemic circulation and is synthesized by peripheral tissues. The availability of IGF-I is regulated by IGF binding proteins. IGF-I enhances the differentiated function of the osteoblast and bone formation. Adult GH deficiency causes low bone turnover osteoporosis with high risk of vertebral and nonvertebral fractures, and the low bone mass can be partially reversed by GH replacement. Acromegaly is characterized by high bone turnover, which can lead to bone loss and vertebral fractures, particularly in patients with coexistent hypogonadism. GH and IGF-I secretion are decreased in aging individuals, and abnormalities in the GH/IGF-I axis play a role in the pathogenesis of the osteoporosis of anorexia nervosa and after glucocorticoid exposure.

Anorexia nervosa and osteoporosis

Anorexia nervosa (AN), a condition of severe undernutrition, is associated with low bone mineral density (BMD) in adults and adolescents. Whereas adult women with AN have an uncoupling of bone turnover markers with increased bone resorption and decreased bone formation markers, adolescents with AN have decreased bone turnover overall. Possible contributors to low BMD in AN include hypoestrogenism and hypoandrogenism, undernutrition with decreased lean body mass, and hypercortisolemia. IGF-I, a known bone trophic factor, is reduced despite elevated growth hormone (GH) levels, leading to an acquired GH resistant state. Elevated ghrelin and peptide YY levels may also contribute to impaired bone metabolism. Weight recovery is associated with recovery of BMD but this is often partial, and long-term and sustained weight recovery may be necessary before significant improvements are observed. Anti-resorptive therapies have been studied in AN with conflicting results. Oral estrogen does not increase BMD or prevent bone loss in AN. The combination of bone anabolic and anti-resorptive therapy (rhIGF-I with oral estrogen), however, did result in a significant increase in BMD in a study of adult women with AN. A better understanding of the pathophysiology of low BMD in AN, and development of effective therapeutic strategies is critical. This is particularly so for adolescents, who are in the process of accruing peak bone mass, and in whom a failure to attain peak bone mass may occur in AN in addition to loss of established bone.

Female athlete triad

Although eating disorders have received much attention over the last few years in athletics, its prevalence was not always well appreciated. Over the years, professional organizations began to pay close attention to the effects of eating disorders, and with this heightened awareness, professionals as well as the general public began to recognize eating disorders as a major problem in our society. In the early 1990s, the American College of Sports Medicine (ACSM) convened the Task Force on Women's Issues in Seattle, Washington . During this conference, members of the ACSM discussed issues related to females and athletics with specific attention to eating disorders, amenorrhea, and osteoporosis. They collectively called these pathologies the Female Athlete Triad (Triad) and hence coined the phrase in 1993. Since the publication, much time and effort has been devoted towards research and understanding of the Triad. In trying to understand this complicated problem, one must grasp the concept that the three pathologies are interrelated and difficult to explain without the influence of any of the other components.

Reduced bone density in HIV-infected women

OBJECTIVES

Although bone density has been previously investigated in HIV-infected men, little is known regarding bone density in HIV-infected women.

METHODS AND DESIGN

Bone density was measured by dual-energy X-ray absorptiometry in 84 ambulatory, HIV-infected females and 63 healthy female control subjects similar in age (41 +/-1 versus 41+/- 1 years, P = 0.83), body mass index (26.0 +/- 0.6 versus 27.0 +/- 0.5 kg/m, P = 0.44) and racial background (% non-Caucasian, 61 versus 51%; P = 0.24, HIV-infected versus control).

RESULTS

Lumbar spine (1.02+/- 0.02 versus 1.07 +/- 0.02 g/cm, P = 0.03) and total hip (0.93 +/-0.01 versus 0.99 +/- 0.01 g/cm, P = 0.004) bone density were reduced in HIV-infected compared with control subjects. Osteopenia was demonstrated in 54 versus 30% (P = 0.004) of HIV-infected versus control subjects and was 2.5 times more likely in a multivariate model accounting for age, race, menstrual function and body mass index. Urinary N-telopeptides of type 1 collagen (NTx) (39.6 +/- 3.5 versus 29.9 +/- 2.0 nM/mM urine creatinine, P = 0.03) and osteoprotegerin (4.76 +/- 0.23 versus 3.39 +/- 0.17 pmol/l, P < or = 0.0001) were increased in HIV-infected compared with control subjects. Among the HIV-infected women, bone density correlated with weight (r = 0.41, P < 0.001) and inversely with urinary NTx (r = -0.28, P = 0.01). Bone density did not differ by current or past protease inhibitor, nucleoside reverse trancriptase inhibitor, or non-nucleoside reverse transcriptase inhibitor exposure.

CONCLUSIONS

HIV-infected women demonstrate reduced bone density. Altered nutritional status, hormonal function and body composition may contribute to lower bone density in HIV-infected women. Consideration should be given to testing bone density in HIV-infected women with risk factors for osteopenia.

[Anorexia nervosa: impact on growth and bone mineral density]

Anorexia nervosa (AN) concerns 1% of adolescent girls and happens at a time of intense bone growth. Adolescents who develop AN before or during puberty have growth retardation and may not achieve their genetic height potential. Osteopenia, as evidenced by dual-energy X-ray absorptiometry, is also frequent. The degree of osteopenia depends on the age of onset and the duration of AN. The role of estrogen deficiency is no more considered paramount with regards to other factors like the fall of growth factor IGF1. The prevention of osteopenia in AN relies mostly on early nutritional intervention. Hormone replacement therapy or calcium/vit D supplements are not sufficient to improve bone density in undernourished patients. New therapeutic strategies combining anabolic and antiresorptive agents are being developed.

Osteoporosis is more prevalent in adrenal than in pituitary Cushing's syndrome

Osteoporosis is the most common complication of Cushing's syndrome. We retrospectively examined the prevalence and risk factors for osteoporosis in 42 female patients with Cushing's syndrome. Osteoporosis and atraumatic fractures were assessed by bone mineral density of the lumbar vertebral spine (L2-L4) using dual energy X-ray absorptiometry (DXA) and X-ray examination. The prevalence of osteoporosis and fracture were 54.8% and 21.4%, respectively. The prevalence of osteoporosis (69.6% vs. 37.8%) and atraumatic bone fracture (26.1% vs. 15.8%) were significantly higher in patients with adrenal Cushing's than in those with pituitary Cushing's. AP and lateral BMD was significantly higher in patients with pituitary origin than in those with adrenal origin. Among several variables examined by multiple logistic regression, the etiology of Cushing's syndrome (adrenal vs. pituitary origin) was a significant factor affecting the prevalence of osteoporosis. Neither age, body mass index, duration of amenorrhea, nor extent of hypercortisolism were significant factors in this analysis. Plasma DHEA-S and urinary 17-KS excretion were significantly higher in pituitary Cushing's than in adrenal Cushing's. The present study shows that the prevalence of osteoporosis in patients with Cushing's syndrome is influenced by its etiology. A factor associated with pituitary Cushing's syndrome, such as adrenal androgen, may protect these patients from glucocorticoid-induced osteoporosis.

Evaluation and treatment of low bone density in anorexia nervosa

The prevalence of anorexia nervosa has increased in recent years, and a large proportion of adults as well as adolescents with this disorder have low bone density and, therefore, an increased risk of fractures. Anorexia nervosa often begins during adolescence, when peak bone mass is accumulated, resulting in significant deficits in bone mass accrual. Therefore, it is important to determine bone mineral density in adolescent and adult women who have this disorder, and to improve or at least stabilize bone metabolism in those with low bone mass. To do this, it is necessary to understand the mechanisms underlying low bone density in anorexia nervosa. This article discusses current concepts related to bone loss associated with anorexia nervosa, including how to prevent it.

Osteoporosis and anorexia nervosa: relative role of endocrine alterations and malnutrition

BACKGROUND AND AIM

Anorexia nervosa (AN) is a psychiatric disorder characterised by self-induced starvation or a very reduced caloric intake, and frequently by severe life-threatening protein calory malnutrition. Its physiological consequences include amenorrhea, estrogen deficiency and osteoporosis. Osteoporosis may develop as a consequence of a lack of estrogens, low calcium or vitamin D intake, hypercortisolemia or the duration of the illness. The aim of this study was to identify the best endocrinological and nutritional indicators of bone density.

SUBJECTS AND METHODS

The study involved 49 young females with AN and malnutrition and 24 age-matched normal controls in whom AN had been excluded on the basis of a clinical evaluation using DSM IV criteria. We studied bone density in early osteopenia, a condition in which the potential risk of fractures is certainly high and traditionally related to a variety of endocrinological and nutritional factors.

RESULTS

Bone density was significantly lower in the AN than the control group in all of the examined bone districts: bone mineral density (BMD) spine 0.89 +/- 0.19 vs 1.27 +/- 0.2 (p<0.0001), BMD neck 0.75 +/- 0.14 vs 1.08 +/- 0.17 (p<0.001), BMD Ward 0.74 +/- 0.17 vs 1.12 +/- 0.11 (p<0.0001). Non-significant differences were found in the patients who had undergone previous estrogen medication. Body mass index (BMI) correlated with bone density, but caloric and calcium intake were not significant predictors. IGF-1, a known nutritionally dependent trophic bone factor, was significantly reduced in our patients but did not correlate with BMD. Like other authors, we found a close correlation between lean body mass and BMD in neck and spine. Physical exercise, urinary free cortisol osteocalcin and type I collagen-telopeptide (NTX) did not significantly correlate with the degree of osteopenia.

CONCLUSIONS

Our data suggest the importance of nutritional factors (particularly lean body mass and BMI) in determining bone mass, and the relatively limited importance of endocrinological factors with the exception of the duration of amenorrhea as an indirect indicator of endocrinological status.

Hypothalamic amenorrhea. The effects of environmental stresses on the reproductive system: a central effect of the central nervous system

Although the treatment of anovulation has become significantly more specialized and complex in the centuries since Hippocrates, a complete understanding of the causes and mechanisms of hypothalamic amenorrhea has not been achieved. Even the best research on hypothalamic amenorrhea is plagued by the lack of longitudinal studies, the use of different exercise models, the difficulty of controlling for caloric intake, and the fact that genetics may have a role in the disorder. Continuing research on metabolic rate, leptin, and other factors will ultimately answer many of the outstanding questions and will help to create better tools for treating this disorder.

Osteoporosis in young people. Research and treatment in eating disorders

We still have much to learn about BMD problems in eating disorders. Much progress has been made in the past 10 years; most clinicians and many patients and their families are now aware of the problem. More research is crucial, however, the authors suggest focusing on three areas: 1. Treatment and prevention: Such studies are difficult to conduct for similar reasons to the difficulties in conducting treatment trials of therapy for AN. First, the relative rarity of the condition makes it difficult to recruit subjects; second, drop-out rates are higher because of ambivalence; and third, the population is heterogeneous both in terms of symptoms and cause. 2. Better understanding of bone turnover in AN. More studies are needed to examine turnover of bone in patients with AN using biochemical markers. In particular, prospective studies are needed to examine the effects of refeeding, weight gain, and treatments such as calcium supplementation. 3. Long-term course of bone density. It would be particularly instructive to examine this in individuals with a short or long history of AN. It would also be useful to study women approaching menopause who had an episode of AN in their teens or early twenties compared with women who were of normal weight during this period.

Bone mineral density in adolescent females with recently diagnosed anorexia nervosa

Anorexia nervosa (AN) can lead to osteoporosis and fractures.

OBJECTIVE

This study evaluated adolescent females with AN diagnosed within the previous 12 months to determine whether there is bone mass reduction and to investigate relationships between nutritional indices (weight, body mass index [BMI], lean mass, fat mass, and percentage fat) and total body (TB) and lumbar spine (LS) bone mineral densities (BMD) and content (BMC).

METHOD

TB and LS BMD and BMC and body composition were measured in 24 adolescent females with AN.

RESULTS

There was no significant reduction in TB or LS BMD. Regression analysis shows significant correlation (p < 0.001) between lean mass and TB BMD (r = +0.83), TB BMC (r = +0.92), LS BMD (r = +0.81), and LS BMC (r = +0.92). There was also a significant relationship between weight percentile and LS BMD z score (p < 0.005; r = +0.60).

DISCUSSION

Adolescent females with early AN do not appear to have reduced bone mass. Lean mass is correlated to BMD and BMC.

Use of hormone replacement therapy to reduce the risk of osteopenia in adolescent girls with anorexia nervosa

PURPOSE

To assess how commonly hormone replacement therapy (HRT) and other measures are prescribed for the treatment of osteopenia in children and adolescents with anorexia nervosa (AN).

METHODS

A self-administered questionnaire was distributed and completed by allopathic and osteopathic physician members of the Society for Adolescent Medicine at its 1998 annual meeting. The questionnaire was also mailed and E-mailed between March 1998 and February 1999. Descriptive statistics included percentages and measures of central tendency.

RESULTS

The questionnaire was completed by 394 of the 1029 physicians surveyed (38.3%). Of the 268 respondents who treated patients with AN under the age of 18 years, 77.6% prescribed HRT. The decision to prescribe HRT was influenced by patient's age but not by bone mineral status. Among those who prescribed HRT, additional therapies included increased caloric intake (89.4%), weight gain (82.2%), increased calcium intake (84.1%), a change in exercise patterns (59.1%), and vitamin D supplementation (37.0%). Only 59 (22.0%) did not use HRT as a treatment modality. One-third of nonprescribers cited the lack of evidence of efficacy of HRT in preventing osteopenia. More recent medical graduates were less likely to prescribe HRT.

CONCLUSIONS

This survey suggests that practitioners caring for adolescent females with AN commonly prescribe HRT for the treatment of osteopenia despite the paucity of evidence demonstrating that it effectively prevents or reverses bone loss associated with this disorder.

Factors predictive of bone mineral density in eating-disordered women: a longitudinal study

OBJECTIVE

Osteoporosis in eating-disordered women is well established, but factors predictive of this condition have proved elusive. The roles of behavioral factors, weight, menstrual status, and the degree of bone mineral density change over the clinical course of the eating disorder were investigated

METHOD

A cohort of 56 eating-disordered women was subjected to bone mineral density measurement at Scan 1 and were followed up between 9 and 51 months later for repeat measurement (n = 10) at Scan 2.

RESULTS

High levels of reduced bone mineral density were observed. Total duration of amenorrhea, body mass index, frequency of vomiting, and cigarette and alcohol consumption accounted for 40% of the variance in spinal bone mineral density measurement at Scan 1. No significant changes in bone mineral density were observed at Scan 2 despite increases in body mass index.

DISCUSSION

The results suggest that increases in weight appear not to be sufficient to increase bone mineral density.

Long-term fracture risk among women with anorexia nervosa: a population-based cohort study

OBJECTIVE

To determine if fractures represent an important problem for women with anorexia nervosa who may fail to achieve peak bone mass and may experience premature bone loss from decreased estrogen levels.

PATIENTS AND METHODS

In this population-based retrospective cohort study, we identified 208 Rochester, Minn, residents that were first diagnosed as having anorexia nervosa between 1935 and 1989, whose subsequent fractures were documented in contemporary medical records and compared with expected numbers of fractures (standardized incidence ratios [SIRs]).

RESULTS

Subjects were followed up for 2689 person-years during which time 45 patients suffered 88 fractures. Fracture risk was increased among the 193 women (SIR, 2.9; 95% confidence interval, 2.0-3.9) as well as the 15 men (SIR, 3.4; 95% confidence interval, 1.1-7.9). The cumulative incidence of any fracture at 40 years after the diagnosis of anorexia nervosa was 57%. Fractures of the hip, spine, and forearm were late complications, occurring on average 38, 25, and 24 years, respectively, after diagnosis.

CONCLUSION

Young women with anorexia nervosa are at increased risk of fractures later in life. Greater attention should be paid to the skeletal health of these individuals.

Osteoporosis in anorexia nervosa

Anorexia nervosa is a disorder characterized by low body weight and amenorrhoea (in females). These features lead to a risk of osteoporosis, a condition in which bone loss leads to weakening of bone structure and increased fracture risk.

Dissociation of bone turnover in anorexia nervosa

Biochemical markers were measured to assess bone turnover in a cross-sectional study of 43 patients with anorexia nervosa; 28 were at their first assessment (untreated) with a body mass index (BMI) (median interquartile range) of 13.3 (2) kg/m2. A second group of 15 patients undergoing treatment (treated) had a median BMI of 17.6 (2.8) kg/m2. The median, interquartile range of urinary deoxypyridinoline (DPyd), a bone resorption marker, was raised in both groups compared with an age-matched control population [DPyd = 17.8 (15.2), 17.5 (16.4) and 9.2 (4.0) nmol/mmol creatinine, respectively]. Serum type 1 collagen carboxyterminal propeptide (P1CP), a marker of bone formation, was similar to controls in the untreated patients [112 (29) and 112 (78.5) ng/ml, respectively], but was significantly raised in the treated patients [163 (219) ng/ml, P < 0.05]. A second group of 21 patients was followed prospectively, on admission and during 8 weeks of intensive inpatient care (BMI on admission and after 8 weeks was 13.0 (2) and 16.7 (3) kg/m2, respectively). The resorption marker, serum type 1 collagen carboxyterminal telopeptide (1CTP) was raised on admission and remained high during treatment. P1CP and osteocalcin levels were similar to control levels on admission but increased with treatment, and after 8 weeks were 40% and 63% higher respectively than on admission. These findings suggest that in untreated anorexia nervosa there was uncoupling of bone turnover as bone resorption markers were raised without a concomitant increase in bone formation markers. As the condition was treated and patients gained weight, the formation markers also increased, leading to a more balanced, although higher, bone turnover.

Compromised bone density 11.4 years after diagnosis of anorexia nervosa

This investigation evaluated bone density in 36 premenopausal women (mean +/- SD age = 29.5 +/- 8.4 years) an average of 11.4 years after diagnosis for anorexia nervosa. Twenty-nine women were aged 20-45 years, and seven were aged 16-19 years. Body composition, age of menarche, length of amenorrhea, estrogen exposure, and lumbar spine and proximal femur bone density were determined. Average appendicular bone density for those > or = 20 years was found to meet World Health Organization T score criteria for osteopenia: total femur T = -1.22 and femoral neck T = -1.33. The average total lumbar Z score for all 36 participants was -0.95, which was 90% of the mean for their age, and the mean Z scores for adolescent subjects were within 91% of the mean for their age (Z = -0.84). Years of estrogen exposure were correlated with lumbar mineral content (r = 0.50, p = 0.002). A modest but significant inverse relationship was observed between length of amenorrhea and femoral and lumbar bone density. The total proximal femur and trochanteric bone densities were best predicted, using stepwise regression, by the number of years after diagnosis and years of amenorrhea, respectively (R2 = 0.23, p = 0.02 and R2 = 0.21, p = 0.04). Lumbar density was best predicted by years of amenorrhea and current percent of ideal body weight (%IBW)(R2 = 0.25, p = 0.02). Length of amenorrhea, estrogen exposure, and %IBW independently contribute to axial and appendicular bone density. Because of risk for compromised bone density, women with a history of anorexia nervosa should be followed longitudinally to maximize premenopausal bone replacement.

Skeletal effects of menstrual disturbances in athletes

This article reviews the skeletal effects and clinical implications of menstrual disturbances in active women. At the lumbar spine, menstrual disturbances are associated with premature bone loss or failure to reach peak bone mass, while appendicular sites are less affected. This suggests that trabecular bone is more sensitive to hormonal stimuli and less responsive to mechanical loading than cortical bone. Although the mechanisms responsible for the detrimental effects of menstrual disturbances are likely to be multifactorial, low circulating levels of oestrogen are thought to be the main cause. The clinical significance of menstrual disturbances depends upon a number of factors, including type of sport, genetic background, body composition and calcium intake. Not all athletes who present with menstrual disturbances will develop osteopenia. Nevertheless, the risk of stress fracture does seem to be increased in athletes with menstrual disturbances and with lower bone density. Whether athletes with menstrual disturbances are at a greater risk for osteoporosis in later life is not yet known. Bone loss can be at least partially reversed, especially with the spontaneous resumption of menses. This may serve to offset any previous increased risk of osteoporosis. Furthermore, other factors, apart from low bone mass, act to determine the likelihood of osteoporotic fractures. Therefore, the clinical significance of menstrual disturbances associated with exercise participation needs to be established for each individual athlete. Bone densitometry may guide the clinician in this respect and assist in the formulation of appropriate management strategies.

Secondary osteoporosis

Secondary osteoporosis is diagnosed when there is a well-established disease-related risk factor for fracture or low bone mass. Secondary osteoporosis is associated with a substantial minority of osteoporotic fractures in women perhaps with a majority of osteoporotic related fractures in men. This chapter does not review all the possible causes of low bone mass and fractures but picks out some of the more important causes of, with an emphasis on the main iatrogenic cause, that is corticosteroid induced osteoporosis. It also highlights some of the possible causes which could be avoidable. Where appropriate the methods of prevention and treatment of secondary osteoporosis are reviewed.

Nutritional management of eating disorders

Abnormal nutritional status and dietary patterns are central features of the eating disorders. Normalization of these features are key components of treatment and recovery because they are powerful perpetuating factors. Restrictive diets, fat avoidance, and abnormal cognitive and perceptual patterns are typically present, in addition to altered nutritional parameters because of hormonal and metabolic factors. The primary goal of nutrition intervention in the patient with anorexia nervosa is to promote weight gain through increased energy intake, expansion of the diet, and knowledgeable and empathetic dietary counseling. A regular pattern of nutritionally balanced, planned meals and snacks, and the avoidance of restrictive dieting, are essential elements of treatment for the patient with bulimia nervosa. As a member of the multidisciplinary treatment team, the dietitian or nutrition professional with knowledge of nutritional science, counseling skills, and a nonjudgmental attitude can provide expertise in this area.

Prevalence of abnormal eating attitudes and behaviors in hospital-based primary and tertiary care clinics: a window of opportunity?

OBJECTIVE

The "athletic triad" of amenorrhea, osteopenia, and eating disorders (EDs) has received increasing attention in the past decade. Adolescents may seek care for amenorrhea or other menstrual irregularity before disclosure of an eating disorder to a primary care clinician. The purpose of this study was to determine the prevalence of abnormal eating attitudes and behaviors in adolescent girls going to a clinic for reproductive endocrinology (RE) visits versus the prevalence in girls going for health maintenance (HM) visits.

DESIGN

All patients aged 8-22 years going to RE or HM clinics were given a 26-item modified eating attitudes test (EAT) and two pages of questions on other eating issues and demographics. Informed consent was obtained from all participants, and also from the parents of those less than 18 years of age.

SETTING

All subjects were seen at a hospital-based ambulatory (HM) or subspecialty (RE) clinic, with both clinics located on the same floor.

PARTICIPANTS

The study included 53 girls from the RE clinic and 108 girls from the HM clinic. All demographics were similar except that the RE patients were slightly older and had significantly more parents with masters or doctorate degrees.

MAIN OUTCOME MEASURES

Study variables were compared between RE and HM groups using either the Student's t test or the Chi-square test, with statistical significance defined as p < 0.05. A score of 20 or higher on the modified EAT was correlated with a high risk of EDs and was used as a measure of prevalence of abnormal eating attitudes and behaviors.

RESULTS

Modified EAT scores were 11.8 +/- 8.9 in RE patients vs 7.0 +/- 7.2 in HM patients (p < 0.001), with 10 (18.9%) RE patients and 7 (6.5%) HM patients having scores of at least 20 (p = 0.016). No differences in daily exercise, dairy consumption, or use of vomiting or laxatives to control weight were found. As expected, RE patients were significantly more likely to experience menstrual irregularities than the HM patients (p < 0.001).

CONCLUSIONS

Adolescents attending a reproductive endocrinology clinic showed a higher prevalence of abnormal eating attitudes and behaviors than did those going to a clinic for HM visits. Early detection of eating disorders may occur both within and outside of the primary care setting through use of a modified EAT.

Bone mass and soft tissue composition in adolescents with anorexia nervosa

The relationship between bone mass and compartments of soft tissue was studied in 22 adolescent women with anorexia nervosa (mean, 17 years). Results were compared to data on age- and gender-matched controls. Bone mass of the lumbar vertebrae and femoral neck, fat and lean tissue was measured by dual energy X-ray absorptiometry (DXA). Bone mass in the central third of the skeleton, by neutron activation analysis (NAA), and body protein, by prompt gamma ray analysis (PGA), was measured on patients, but not controls. The patients had significantly lower values than controls in total weight (26%), lean tissue (16%), fat (60%), bone mass of lumbar spine (14%), and femoral neck (15%). The mean calcium bone index (CaBI), the central skeletal calcium normalized for body size based on height, was significantly lower than the value for external controls, (0.86 +/- 0.10 vs. 0.97 +/- 0.10). The nitrogen index (NI), body protein normalized for height, showed a similar reduction from external controls (0.84 +/- 0.10 vs. 1.0 +/- 0.10). Bone mass (both DXA and NAA data) was strongly correlated to lean tissue and to protein; the correlations to fat were weaker. Follow-up studies after 7-26 months in 12 patients showed a modest increase in weight (mean, 4.9 kg) which was due, primarily, to an increase in fat with only insignificant increase in lean tissue and in protein. In bone mass, there was either no change or further loss. Only four restored body weight to normal (BMI > 20) and they achieved normal menstruation, but even these four responders showed no increase in bone mass. Our studies confirm that adolescent females with anorexia nervosa suffer losses not only in all compartments of body composition, but also demonstrate that the restoration of bone mass lags behind improvement in soft tissue compartments. These results were independent of methods used for the measurements.

Bone metabolism and osteopenia in eating disorders

Bone loss is a potentially debilitating condition in women with eating disorders. Complications may include failure to achieve peak bone mass, increased risk of premature fractures, and inability to reach the height potential. We therefore conducted a comprehensive evaluation of 58 women with anorexia nervosa (AN), bulimia (BUL) and anorexia/bulimia (AB), comparing bone mineral density (BMD) to physical parameters, biochemical indices, and markers for bone formation and resorption. BMDs were significantly lower in patients with AN than in those with AB and BUL, and overt osteopenia was uncommon in AB and BUL. Hypercortisolism was the best laboratory marker to assess the risk of osteopenia in patients with AN. However, there were no associated changes in bone formation or resorption parameters. No direct correlation was found between BMD and body mass index, estrogen deficiency, tubular reabsorption of phosphorus, serum vitamin D, PTH, BGP, or alkaline phosphatase levels. Although the prognosis for complete recovery to normal BMD is poor, treatment of the underlying depressive disorder, improvement in nutrition with increased weight, and spontaneous resumption of menses are associated with restoring bone health.

Osteoporosis as a pediatric problem

Osteoporosis has long been considered a disease of the elderly; however, there is now a general agreement that predisposition begins in childhood and adolescence; thus, rational approaches to prevention of the disease should be started during childhood and adolescence. Indeed, by determining PBM, events occurring in the first two decades of life may determine in large part the subsequent risk of osteoporosis. Attention has thus been focused on the physiology of bone mass accumulation during growth, including the role of environmental factors such as dietary calcium and exercise. Because their patients are at this particular time of life, when PBM is being achieved, pediatricians are in a critical position to affect changes in the long-term risk of osteoporosis in their female and male patients.

Optimizing peak bone mass: what are the therapeutic possibilities?

Bone mass in the elderly depends on the rate of involutional bone loss and on the peak bone mass, i.e. the bone mass present around the third decade of life. Factors relating to the attainment of peak bone mass include congenital factors, diet, hormones, physical activity, life-style factors, drugs and diseases. A therapeutic intervention aimed at increasing peak bone mass is conceivable only by controlling factors such as estrogen status, dietary calcium intake and physical activity. Calcium intake appears to be relevant up to the so-called threshold intake (1000 mg/day), but higher allowances do not seem to offer additive advantages. Exercise affects only the regions of the skeleton under mechanical stress. Estrogen administration is realistic only in conditions characterized by severe hypoestrogenism.

Secondary osteoporosis

Osteoporosis with attendant increased fracture risk is a common complication of many other diseases. Indeed, almost all chronic diseases make some impact on life-style, usually by restricting physical activity and hence reducing the anabolic effect of exercise and gravitational strains on the skeleton. Restricted appetite and modified gastrointestinal tract function is another commonplace finding that has an impact on bone nutrition and synthesis, as on other systems. Sex hormone status is of particular importance for the maintenance of the normal skeleton, and the postmenopausal woman is at particular risk for most causes of secondary osteoporosis. In dealing with secondary osteoporosis in the hypo-oestrogenic woman, the question of giving hormone replacement therapy in addition to other disease-specific therapy should always be considered, as, for example, in a young amenorrhoeic woman with Crohn's disease. Similarly, in hypogonadal men the administration of testosterone is useful for bone conservation. The wider availability of bone densitometry ought to make us more aware of the presence of osteoporosis in the many disease states discussed above. This is particularly important as the life span of such patients is now increased by improved management of the underlying disease process in many instances. Even in steroid-induced osteoporosis--one of the commonest and most severe forms of osteoporosis--we now have some effective therapy in the form of the bisphosphonates and other anti-bone-resorbing drug classes. The possibility of prophylaxis against secondary osteoporosis has therefore become a possibility, although the very long-term effects of such drug regimens are still unknown. In some situations, such as thyrotoxicosis, Cushing's syndrome and immobilization, spontaneous resolution of at least part of the osteoporosis is possible after cure of the underlying problem. The shorter the existence of the basic problem, the more successful the restoration of the skeleton appears to be. A useful credo for clinicians with respect to secondary osteoporosis is: to think of it; to use specific therapy for the underlying disease; to reduce or remove completely any relevant drug or toxic material; to optimize physical activity and general nutrition; to treat hypogonadism if present and feasible; and to consider the use of specific anti-bone-resorbing or other bone active drugs.