Ultrasound and X-ray-based bone densitometry in patients with anorexia nervosa

Radiofrequency echographic multispectrometry (REMS): an innovative technique for the assessment of bone status in young women with anorexia nervosa

PURPOSE

Reduced bone mineral density (BMD) and increase risk of fragility fracture are common complication of anorexia nervosa (AN). BMD by dual-energy X-ray absorptiometry (DXA) present several limits in subjects with AN. This study aimed to evaluate the usefulness of the new Radiofrequency echographic multispectrometry (REMS) technique in the assessment of bone status in young women with AN.

METHODS

In a cohort of 50 subjects with restrictive AN and in 30 healthy controls, we measured BMD at the lumbar spine (LS-BMD), at femoral neck (FN-BMD) and total hip (TH-BMD) using both DXA and REMS technique.

RESULTS

BMD evaluated by DXA and REMS technique at all measurement sites were all significantly (p < 0.01) lower in subjects suffering from AN subjects than in controls. Good correlations were detected between BMD by DXA and BMD by REMS measurements at LS (r = 0.64, p < 0.01) at FN (r = 0.86, p < 0.01) and at TH (r = 0.84, p < 0.01) in subjects suffering from AN. Moreover, Bland-Altman analysis confirmed the good agreement between the two techniques. The subjects suffering from AN with previous vertebral fragility fractures presented lower values of both BMD-LS and BMD-TH by DXA and by REMS with respect to those without fractures; however, the difference was significant only for BMD-TH by REMS (p < 0.05).

CONCLUSIONS

Our data suggest that REMS technique due to its characteristic of precision and reproducibility may represent an important tool for the evaluation of the changes in bone status in AN young women, especially during the fertile age and in case of pregnancy and breastfeeding.

LEVEL OF EVIDENCE

Level of evidence: level III cohort study.

Associations between bone mineral density, body composition and amenorrhoea in females with eating disorders: a systematic review and meta-analysis

BACKGROUND

Lower bone mineral density (BMD) increases the risk of osteoporosis in individuals with eating disorders (EDs), particularly women with anorexia nervosa (AN), making them susceptible to pain and fractures throughout adulthood. In AN, low weight, hypothalamic amenorrhoea, and longer illness duration are established risk factors for low BMD, and in people with other EDs a history of AN seems to be an important risk factor for low BMD.

PURPOSE

To conduct a systematic review and meta-analysis of BMD in individuals with EDs, including AN, bulimia nervosa (BN), binge-eating disorder (BED) and other specified feeding or eating disorders (OSFED) compared to healthy controls (HC).

METHODS

Following PRISMA guidelines, electronic databases were reviewed and supplemented with a literature search until 2/2022 of publications measuring BMD (dual-energy X-ray absorptiometry or dual photon absorptiometry) in females with any current ED diagnosis and a HC group. Primary outcomes were spine, hip, femur and total body BMD. Explanatory variables were fat mass, lean mass and ED clinical characteristics (age, illness duration, body mass index (BMI), amenorrhoea occurrence and duration, and oral contraceptives use).

RESULTS

Forty-three studies were identified (N = 4163 women, mean age 23.4 years, min: 14.0, max: 37.4). No study with individuals with BED met the inclusion criteria. BMD in individuals with AN (total body, spine, hip, and femur), with BN (total body and spine) and with OSFED (spine) was lower than in HC. Meta-regression analyses of women with any ED (AN, BN or OSFED) (N = 2058) showed low BMI, low fat mass, low lean mass and being amenorrhoeic significantly associated with lower total body and spine BMD. In AN, only low fat mass was significantly associated with low total body BMD.

CONCLUSION

Predictors of low BMD were low BMI, low fat mass, low lean mass and amenorrhoea, but not age or illness duration. In people with EDs, body composition measurement and menstrual status, in addition to BMI, are likely to provide a more accurate assessment of individual risk to low BMD and osteoporosis.

The quantitative ultrasound method for assessing low bone mass in women with anorexia nervosa

This study investigated the potential role of quantitative ultrasound (QUS) to assess low bone mass in anorexia nervosa patients (AN). Bone parameters from QUS and DXA were positively correlated and significantly reduced in AN compared with controls, suggesting that QUS is a pertinent technique to assess low bone mass in these patients.

PURPOSE

The aim of this study was to investigate the potential role of an alternative technique, quantitative ultrasound (QUS), to assess low bone mass in patients with anorexia nervosa (AN).

METHODS

Two hundred seven young women (134 patients with AN and 73 healthy controls) with ages ranging from 14.4 to 38.4 years participated in this observational cross-sectional study. Bone mass was concomitantly evaluated by DXA to determine areal bone mineral density (aBMD; g/cm²) at hip, lumbar spine, and radius and by QUS to determine broadband ultrasound attenuation (BUA; dB/MHz) at the heel.

RESULTS

BUA (66.5 ± 4.6 dB/MHz vs 61.0 ± 5.0 dB/MHz) and aBMD at the hip (0.916 ± 0.013 g/cm² vs 0.806 ± 0.010 g/cm²), lumbar spine (0.966 ± 0.012 g/cm² vs 0.886 ± 0.010 g/cm²), and radius (0.545 ± 0.005 g/cm² vs 0.526 ± 0.04 g/cm²) were significantly decreased (p < 0.01) in patients with AN compared with controls. When patient and control data were pooled, BUA was significantly correlated with aBMD at the hip (r = 0.60, p < 0.001), lumbar spine (r = 0.48, p < 0.001), and radius (r = 0.40, p<0.001). In patients with AN, BUA and aBMD were mainly and positively correlated with weight, lean tissue mass, body mass index (BMI), and minimal BMI life and negatively with the duration of both disease and amenorrhea. Better concordance between the two techniques was obtained when absolute BUA and aBMD values were used according to the WHO T score classification.

CONCLUSION

BUA measurement at the heel by QUS appears to be a pertinent nonionizing technique to assess low bone mass in patients with AN.

Forearm bone mineralization in recently diagnosed female adolescents with a premenarchal onset of anorexia nervosa

OBJECTIVE

Data available on bone mineralization by peripheral quantitative computed tomography (pQCT) in adolescents with an early onset anorexia nervosa (AN) is limited. We investigated whether a disturbed bone mineralization can be observed at the distal radius in recently diagnosed female adolescents with AN and a premenarchal onset of this disease.

METHOD

Twenty-four premenarchal patients with AN and 22 healthy females which were age and height matched, were selected from our reference database; both groups underwent a pQCT bone assessment at the distal radius of the nondominant arm.

RESULTS

The patients age ranged between 13.3 and 18.4 years. Their percent weight loss ranged between 5 and 36% (median 23%) and occurred within the preceding 3 to 44 months. Trabecular volumetric bone mineral density of the patient group was significantly lower than the comparison group (185.6 ± 30.2 vs.209.3 ± 34.0 mm(2) ; p = 0.02). Bone cross-sectional area, bone mineral content, total volumetric bone mineral density and periosteal circumference were also lower, albeit not significantly. The bone parameters were unrelated to the under nutrition severity and duration.

DISCUSSION

In premenarchal patients with AN the trabecular bone mineralization of the forearm is significantly reduced, this might be an early indicator of altered bone mineral accrual. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2016; 49:809-812).

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.

Bone mineral density, osteoporosis, and fractures among people with eating disorders: a systematic review and meta-analysis

OBJECTIVE

To provide meta-analytical evidence of bone mineral density (BMD), fractures, and osteoporosis rates in eating disorders (ED) vs. healthy controls (HCs).

METHOD

Three independent authors searched major electronic databases from inception till August 2015 for cross-sectional studies reporting BMD in people with ED (anorexia nervosa, (AN); bulimia nervosa, (BN); eating disorders not otherwise specified, (EDNOS)) vs. HCs. Standardized mean differences (SMDs) ±95% and confidence intervals (CIs) were calculated for BMD, and odds ratios (ORs) for osteopenia, osteoporosis, and fractures.

RESULTS

Overall, 57 studies were eligible, including 21 607 participants (ED = 6485, HCs = 15 122). Compared to HC, AN subjects had significantly lower BMD values at lumbar spine (SMD = -1.51, 95% CI = -1.75, -1.27, studies = 42), total hip (SMD = -1.56, 95%CI = -1.84, -1.28, studies = 23), intertrochanteric region (SMD = -1.80, 95%CI = -2.46, -1.14, studies = 7), trochanteric region (SMD = -1.05, 95%CI = -1.44, -0.66, studies = 7), and femoral neck (SMD = -0.98, 95%CI = -1.12, -0.77, studies = 20). Reduced BMD was moderated by ED illness duration and amenorrhea (P < 0.05). AN was associated with an increased likelihood of osteoporosis (OR = 12.59, 95%CI = 3.30-47.9, P < 0.001, studies = 4) and fractures (OR = 1.84, 95% CI = 1.17-2.89, I(2) = 56, studies = 6). No difference in BMD was found between BN and EDNOS vs. HC.

CONCLUSION

People with AN have reduced BMD, increased odds of osteoporosis and risk of fractures. Proactive monitoring and interventions are required to ameliorate bone loss in AN.

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.

Obstacles in the optimization of bone health outcomes in the female athlete triad

Maintaining low body weight for the sake of performance and aesthetic purposes is a common feature among young girls and women who exercise on a regular basis, including elite, college and high-school athletes, members of fitness centres, and recreational exercisers. High energy expenditure without adequate compensation in energy intake leads to an energy deficiency, which may ultimately affect reproductive function and bone health. The combination of low energy availability, menstrual disturbances and low bone mineral density is referred to as the 'female athlete triad'. Not all athletes seek medical assistance in response to the absence of menstruation for 3 or more months as some believe that long-term amenorrhoea is not harmful. Indeed, many women may not seek medical attention until they sustain a stress fracture. This review investigates current issues, controversies and strategies in the clinical management of bone health concerns related to the female athlete triad. Current recommendations focus on either increasing energy intake or decreasing energy expenditure, as this approach remains the most efficient strategy to prevent further bone health complications. However, convincing the athlete to increase energy availability can be extremely challenging. Oral contraceptive therapy seems to be a common strategy chosen by many physicians to address bone health issues in young women with amenorrhoea, although there is little evidence that this strategy improves bone mineral density in this population. Assessment of bone health itself is difficult due to the limitations of dual-energy X-ray absorptiometry (DXA) to estimate bone strength. Understanding how bone strength is affected by low energy availability, weight gain and resumption of menses requires further investigations using 3-dimensional bone imaging techniques in order to improve the clinical management of the female athlete triad.

Distal radius in adolescent girls with anorexia nervosa: trabecular structure analysis with high-resolution flat-panel volume CT

PURPOSE

To examine trabecular microarchitecture with high-resolution flat-panel volume computed tomography (CT) and bone mineral density (BMD) with dual-energy x-ray absorptiometry (DXA) in adolescent girls with anorexia nervosa (AN) and to compare these results with those in normal-weight control subjects.

MATERIALS AND METHODS

The study was approved by the institutional review board and complied with HIPAA guidelines. Informed consent was obtained. Twenty adolescent girls, 10 with mild AN (mean age, 15.9 years; range, 13-18 years) and 10 age- and sex-matched normal-weight control subjects (mean age, 15.9 years; range, 12-18 years) underwent flat-panel volume CT of distal radius to determine apparent trabecular bone volume fraction (BV/TV), apparent trabecular number (TbN), apparent trabecular thickness (TbTh), and apparent trabecular separation (TbSp). All subjects underwent DXA of spine, hip, and whole body to determine BMD and body composition. The means and standard deviations (SDs) of structure parameters were calculated for AN and control groups. Groups were compared (Student t test). Linear regression analysis was performed.

RESULTS

AN subjects compared with control subjects, respectively, showed significantly lower mean values for BV/TV (0.37% +/- 0.05 [SD] vs 0.46% +/- 0.03, P = .0002) and TbTh (0.31 mm +/- 0.03 vs 0.39 mm +/- 0.03, P < .0001) and higher mean values for TbSp (0.54 mm +/- 0.13 vs 0.44 mm +/- 0.04, P = .02). TbN was lower in AN subjects than in control subjects, but the difference was not significant (1.17 mm(-3) +/- 0.15 vs 1.22 mm(-3) +/- 0.07, P = .43). There was no significant difference in BMD between AN and control subjects. BMD parameters showed positive correlation with BV/TV and TbTh in the control group (r = 0.55-0.84, P = .05-.01) but not in AN patients.

CONCLUSION

Flat-panel volume CT is effective in evaluation of trabecular structure in adolescent girls with AN and demonstrates that bone structure is abnormal in these patients compared with that in normal-weight control subjects despite normal BMD.

SUPPLEMENTAL MATERIAL

http://radiology.rsnajnls.org/cgi/content/full/249/3/938/DC1.

Screening for osteoporosis in anorexia nervosa: prevalence and predictors of reduced bone mineral density

OBJECTIVE

Decreased bone mineral density (BMD) in anorexia nervosa (AN) can be detected easily by dual-energy X-ray absorptiometry (DXA). This study was designed to assess the prevalence of osteoporosis and osteopenia in AN, identify predictors, and determine the diagnostic yield of screening with DXA.

METHOD

DXA was used to screen 59 unselected adult patients with a history of AN.

RESULTS

Osteoporosis was identified in 18 patients (31%) and osteopenia in 30 (51%). The spine had a lower mean T-score than either the hip or femur. BMI significantly predicted T-score (p = 0.0006) and the odds of having osteoporosis (p = 0.0188). There was a significant association between use of oestrogens and the presence of osteoporosis or osteopenia (p = 0.0491). There was no significant association between duration of AN and T-score. A duration of AN of less than 1 year was found in 12% of those with osteoporosis.

CONCLUSION

BMI is a strong predictor of BMD in AN. DXA is an effective screening tool and should probably be offered routinely.

Pediatric dual-energy X-ray absorptiometry: technique, interpretation, and clinical applications

This article reviews the dual-energy x-ray absorptiometry (DXA) technique, its interpretation, and clinical applications with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist," monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist," aware of the DXA findings in a large number of clinical diseases, providing the referring clinician with a meaningful context for the numeric result obtained with DXA.

Pediatric DXA: clinical applications

Normal bone mineral accrual requires adequate dietary intake of calcium, vitamin D and other nutrients; hepatic and renal activation of vitamin D; normal hormone levels (thyroid, parathyroid, reproductive and growth hormones); and neuromuscular functioning with sufficient stress upon the skeleton to induce bone deposition. The presence of genetic or acquired diseases and the therapies that are used to treat them can also impact bone health. Since the introduction of clinical DXA in pediatrics in the early 1990s, there has been considerable investigation into the causes of low bone mineral density (BMD) in children. Pediatricians have also become aware of the role adequate bone mass accrual in childhood has in preventing osteoporotic fractures in late adulthood. Additionally, the availability of medications to improve BMD has increased with the development of bisphosphonates. These factors have led to the increased utilization of DXA in pediatrics. This review summarizes much of the previous research regarding BMD in children and is meant to assist radiologists and clinicians with DXA utilization and interpretation.

Skeletal measurements by quantitative ultrasound in adolescents and young women with anorexia nervosa

OBJECTIVE

To compare quantitative ultrasound (QUS) measurements in adolescents with anorexia nervosa (AN) with that in healthy control subjects and to determine the utility of QUS as a tool to evaluate skeletal status in these patients.

STUDY DESIGN

Female adolescents with AN (n = 41) and healthy control subjects (n = 105) were recruited. Speed of sound (SOS) was measured at the radius and tibia. Participants with AN also had hip and spinal areal bone mineral density measurements by dual-energy x-ray absorptiometry (DXA); bone mineral apparent density (BMAD) was calculated.

RESULTS

Subjects with AN had higher mean radial SOS (4044 +/- 99 m/s) than did control subjects (3947 +/- 116 m/s; P < .0001). These results were replicated at the tibia (AN, 3918 +/- 85 m/s vs control subjects, 3827 +/- 106 m/s; P < .0001). Neither DXA measures of areal bone mineral density nor BMAD were correlated with SOS. Weight and body mass index were negative predictors of tibial but not radial SOS. AN status remained a significant predictor of SOS after controlling for body mass index, age, and race.

CONCLUSIONS

Subjects with AN had higher mean tibial and radial SOS than did control subjects. QUS variables did not correlate with DXA measures, calculated BMAD, or anthropometric variables. QUS measurements of SOS do not appear to be appropriate for bone density screening in patients with AN.

Cortical and trabecular bone density and structure in anorexia nervosa

The aim of the study was to examine bone density and architecture with three different measurement methods in a sample of young women with anorexia nervosa (AN) and in an age-matched control group of women. Three-dimensional periphery quantitative computer tomography (3D-pQCT) at the ultradistal radius, a new technology providing measures of cortical and trabecular bone density and architecture, was performed, as well as quantitative ultrasound (QUS) at the heel, and dual energy X-ray absorptiometry (DXA) at the spine and hip. Thirty-six women with AN aged 18-30 years (mean duration of AN: 5.8 years) and 30 age-matched women were assessed. Bone mineral density measured by DXA at the spine and hip, and broadband ultrasound attenuation measured by QUS at the heel were significantly lower in patients than controls. 3D-pQCT demonstrated a highly significant deficit in the absolute number of bone trabecules and a significant reduction of cortical thickness. Severity of underweight was significantly associated with bone deficits at the hip measured by DXA. 3D-pQCT revealed mostly deficits of cortical bone related with age of onset of eating disorder. Using three different methods to measure bone density and bone structure at the hip, spine, heel and ultradistal radius, significant deficits in bone mineral density both in trabecular and cortical bone, as well in trabecular structure could be demonstrated in the AN patients.

Osteoporosis in anorexia nervosa: prevention and treatment

BACKGROUND

Osteoporosis is a very prevalent complication of anorexia nervosa. In contrast to the many other medical complications of anorexia, osteoporosis and its sequelae of fractures, kyphosis, and pain may persist regardless of the overall treatment outcome.

DISCUSSION

Traditional well-proven therapies for postmenopausal osteoporosis are not as effective against osteoporosis in anorexia nervosa. Therefore, clinicians who treat these patients must become increasingly vigilant about osteoporosis in regards to preventive, diagnostic, and treatment strategies.

Is ultrasound of bone relevant for corticosteroid-treated patients? A comparative study with bone densitometry measured by DEXA

Corticosteroid treatment diminishes bone mass and alters bone quality. The objective was to evaluate bone in corticosteroid-treated patients and controls and in fractured and non-fractured patients treated with corticosteroids using both X-ray densitometry (DEXA) and ultrasound. We evaluated 34 women aged 58 +/- 14 years (X +/- SD), who had been on long-term low dose prednisone therapy for at least 6 months, and who had never received specific treatment for osteoporosis. Bone mineral density of total skeleton (TS), lumbar spine (LS), femoral neck (FN), and vertebral morphometry (MXA) were measured by DEXA. Speed of sound (SOS), broadband ultrasound attenuation (BUA) and stiffness were measured using an Achilles Plus system. Forty-two healthy women served as controls. Both densitometric and ultrasound parameters in the patients were significantly diminished compared with controls: TS: P < 0.002, LS: P < 0.025, FS: P < 0.005, Stiffness: P < 0.001, BUA: P < 0.002 and SOS: P < 0.002. The percentage of patients with a Z score below -2 was higher in Stiffness and BUA: 38% and 47%, respectively, compared with a range of 16-24% in the other parameters (P < 0.05 BUA vs. DEXA measurements). Eleven patients with previous bone fracture had values lower than the non-fractured patients, both according to DEXA and ultrasound measurements, but the difference was only significant for BUA (P < 0.02). BUA of the calcaneus was more effective in detecting the specific skeletal alterations and fracture risk of the group of patients receiving chronic corticosteroid treatment.

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.

Current concepts in pediatric bone disease

It is widely believed that osteoporosis prevention may be best accomplished during childhood and adolescence, when bones are growing rapidly and are most sensitive to environmental influences, such as diet and physical activity. For children with chronic diseases, a variety of factors may influence normal bone mineralization, including altered growth, delayed maturation, inflammation, malabsorption, reduced physical activity, glucocorticoid exposure, and poor dietary intake. In healthy children, maintaining adequate levels of calcium intake, serum vitamin D, and weightbearing physical activity may be sufficient to prevent osteoporosis later in life. Far less is known about effective prevention and treatment of poor bone mineralization in children with chronic illness, such as CF or CD. Osteoporosis prevention and intervention measures during childhood are limited by the paucity of reference data on bone mineralization. Although it is widely recognized that puberty, skeletal maturation, and body size influence BMC and bone density, no reference data for bone mineralization are scaled to these important measures. In children with chronic disease with delayed growth and maturation, the creation of such reference data is of paramount importance. In addition, the dynamic changes that occur during growth and maturation in the structural characteristics of trabecular and cortical bone and the development of the bone-muscle unit may influence current and future fracture risk. Further research is needed to characterize these changes and their use in the assessment of bone health and fracture risk in children. Only then can the impact of treatment strategies be appreciated fully.

Ultrasound parameters of calcaneal bone density in girls with anorexia nervosa

Osteoporosis is common in patients with anorexia nervosa (AN), but ultrasound has so far been scarcely used to detect it We measured calcaneal broadband ultrasound attenuation (BUA) and velocity of sound (VOS) in 26 AN girls (mean age 15.1+/- 1.5 years) using a Cuba Clinical device (McCue Ultrasonics, UK). Basic anthropometric (body weight, height and body mass index--BMI) and clinical data (mean duration of AN, number of absent cycles, weight loss) were collected. All of the girls reported that they did at least one hour's vigorous exercise a day. BUA was significantly lower (p<0.004) and VOS significantly higher (p<0.0001) in comparison with reference data. Body weight and BMI at the time of the measurements were significantly lower than the reference data (p<0.0001). There were no correlations between body weight or height and BUA or VOS, but there was a slight correlation between BUA and BMI (r=0.4, p<0.05) and a slight inverse correlation between VOS, body weight and BMI (r=-0.48 and r=-0.43, p<0.01). VOS slightly correlated with weight loss (r=0.4, p<0.05), significantly with the weekly number of exercise hours (r=0.48, p<0.01). The duration of AN, the number of missed cycles and the percentage of weight loss did not correlate with BUA, and neither the duration of AN nor the number of missed cycles correlated with VOS. The low BUA value could be attributed to poor nutrition, and substantial physical activity may lead to the increase in VOS. In conclusion, girls with AN have low BUA and high VOS values, neither of which correlate with the duration of AN or the number of missed cycles.

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.