Osteoporosis in Chinese patients with anorexia nervosa

Prevalence and risk factors associated with low bone mineral density in Asian adolescents with anorexia nervosa and atypical anorexia nervosa

OBJECTIVE

This retrospective study aimed to evaluate the prevalence and risk factors for low bone mineral density (BMD) at diagnosis in Asian adolescent females with anorexia nervosa (AN) and atypical AN.

METHOD

We analyzed the BMD results for 213 patients between 10 and 18 years of age, with AN and atypical AN receiving care at a pediatric hospital in Singapore. We used linear regression analyses to determine if type of eating disorder, premorbid weight, and duration of amenorrhea were risk factors for low BMD. For a subset of patients with repeat BMD evaluation, we used paired t-tests to assess the impact of weight or menstrual restoration on the change in BMD.

RESULTS

The prevalence of BMD height-for-age Z-scores <-2 at presentation was higher in patients with AN (13.0%) than atypical AN (2.3%) (p = .034). In multivariate regression, a diagnosis of atypical AN was protective against low BMD at the lumbar spine (B = 0.394, p = .009) and total body less head (B = 0.774, p = .010). Duration of amenorrhea was not associated with BMD across all sites. For those with repeat BMD measures, there was significantly less deterioration in the BMD Z-scores for patients with weight or menstrual restoration (R = -0.22 ± 0.59, NR = -0.69 ± 0.43, p = .029).

CONCLUSIONS

Duration of amenorrhea was not associated with BMD in this sample. A diagnosis of AN was correlated with lower BMD than atypical AN. Further research is needed to better understand the relationship between amenorrhea, weight status, and bone health in Asian adolescents with eating disorders.

PUBLIC SIGNIFICANCE

In this sample, 13% of Asian adolescents with AN and 2.3% of Asian adolescents with atypical AN have low BMD. In our study population, duration of amenorrhea was not correlated with BMD. Among adolescents with AN, a history of being underweight at the highest pre-morbid BMI, is correlated with low BMD. It is important for physicians to take a thorough weight history in evaluating bone health in this population.

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.

Teenage Diet: Context and Companions Determine Eating Habits

Objetivo: presentar los significados de la alimentación y las prácticas relacionadas de un grupo de adolescentes escolarizados del colegio Nuestra Señora de Guadalupe, de Cali, Colombia. Método: estudio con abordaje cualitativo de tipo exploratorio, orientado por la hermenéutica dialéctica, utilizando como técnica el análisis de contenido. Se tuvieron en cuenta los espacios familiares, escolares y de la calle, donde los adolescentes interactúan con sus pares o amigos. Participaron 31 adolescentes (17 mujeres y 14 hombres), 10 familiares (6 madres, 2 padres y 2 abuelas), 3 profesores y la administradora de la cafetería. Resultados: de acuerdo con el espacio y la compañía se establecieron subcategorías que determinan e influyen en el tipo de alimentos que consumen los adolescentes, así: en la familia, las tradiciones; en el colegio, la autonomía, la disponibilidad económica, las preferencias del grupo y la oferta de alimentos en la cafetería; en la calle, el género, la amistad y el amor inciden en la elección e ingesta de alimentos. Conclusiones: el espacio y la compañía determinan el tipo y la calidad de los alimentos ingeridos por los adolescentes.

Osteoporosis in anorexia nervosa

Osteoporosis is common in anorexia nervosa. It places these patients at increased lifetime risk for fractures. Bone loss may never recover completely even once weight is restored. The strongest predictors of osteoporosis include low body weight and amenorrhea. Loss of bone density can occur rapidly and very early in the course of anorexia nervosa. The etiology of bone loss in the patient with anorexia nervosa is multifactorial. In addition to reduced estrogen and progesterone, excess cortisol levels and low levels of insulin growth factor (IGF-1), a correlate for bone formation, are observed. Dual energy x-ray absorptiometry screening is important to assess bone density. However, successful treatments to reverse bone loss, in those with anorexia nervosa, are lacking. Early diagnosis and treatment of anorexia nervosa are paramount to prevent initial weight loss and subsequent loss of bone.

Thin healthy women have a similar low bone mass to women with anorexia nervosa

An association between anorexia nerviosa (AN) and low bone mass has been demonstrated. Bone loss associated with AN involves hormonal and nutritional impairments, though their exact contribution is not clearly established. We compared bone mass in AN patients with women of similar weight with no criteria for AN, and a third group of healthy, normal-weight, age-matched women. The study included forty-eight patients with AN, twenty-two healthy eumenorrhoeic women with low weight (LW group; BMI < 18·5 kg/m2) and twenty healthy women with BMI >18·5 kg/m2 (control group), all of similar age. We measured lean body mass, percentage fat mass, total bone mineral content (BMC) and bone mineral density in lumbar spine (BMD LS) and in total (tBMD). We measured anthropometric parameters, leptin and growth hormone. The control group had greater tBMD and BMD LS than the other groups, with no differences between the AN and LW groups. No differences were found in tBMD, BMD LS and total BMC between the restrictive (n 25) and binge–purge type (n 23) in AN patients. In AN, minimum weight (P = 0·002) and percentage fat mass (P = 0·02) explained BMD LS variation (r2 0·48) and minimum weight (r2 0·42; P = 0·002) for tBMD in stepwise regression analyses. In the LW group, BMI explained BMD LS (r2 0·72; P = 0·01) and tBMD (r2 0·57; P = 0·04). We concluded that patients with AN had similar BMD to healthy thin women. Anthropometric parameters could contribute more significantly than oestrogen deficiency in the achievement of peak bone mass in AN patients.

Treatment of osteopenia and osteoporosis in anorexia nervosa: a systematic review of the literature

OBJECTIVE

To systematically review the evidence supporting treatment of osteopenia and osteoporosis in patients with anorexia nervosa (AN).

DATA SOURCES

We identified controlled clinical studies of interventions for low bone mass in AN via searches of MEDLINE; the Cochrane Library; EMBASE; PsycINFO; and cumulative index to nursing and allied health literature. Outcomes of interest were changes in bone mineral density and fracture incidence.

RESULTS

Six randomized controlled trials (RCTs) and two cohort trials examined five classes of medical therapy on bone mineral density outcomes. One RCT of bisphosphonates showed no benefit and a second flawed RCT showed some benefit; one RCT showed a benefit of insulin-like growth factor-I; none of the five trials evaluating estrogen therapy showed benefit.

DISCUSSION

Although patients with AN are often losing bone mass when they should be optimizing bone growth, there is no good evidence to guide medicinal interventions. Therefore, early detection and weight restoration are of utmost importance whereas ongoing trials define effective therapies.

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.

A study of bone density change in patients with anorexia nervosa

In patients with anorexia nervosa (AN) several factors combine to cause osteoporosis, and the risk of osteoporosis increases with chronicity of illness. The authors carried out a follow-up study in patients who attended the Eating Disorders department of the Hospital de Santa Maria. The average follow-up period was of 7.6 years. Fifteen patients were included. Patients answered clinical history questions and underwent neck of femur and spine densitometry. The most important variable with negative correlations to bone recovery was disease duration. A positive correlation between bone recovery and time since the first menstrual cycle post-amenorrhea was also found. However, AN is a condition in which once weight improves and menstrual cycles become regular, severe damage to bone structure is still likely to be maintained.