Effect of Transdermal Estradiol and Insulin-like Growth Factor-1 on Bone Endpoints of Young Women With Anorexia Nervosa

Bone Density, Geometry, Structure and Strength Estimates in Adolescent and Young Adult Women with Atypical Anorexia Nervosa versus Typical Anorexia Nervosa and Normal-Weight Healthy Controls

Our objective was to characterize bone outcomes in adolescent and young adult women with atypical anorexia nervosa (AAN) compared to typical AN and normal-weight healthy controls (HC) based on DSM-5 criteria. Four hundred thirty-two participants (141 AN, 131 AAN and 160 HC), ages 12-21 years, underwent dual-energy X-ray absorptiometry for areal BMD, and a subset had high-resolution peripheral quantitative CT assessment of the distal radius and tibia for volumetric BMD (vBMD), bone geometry and microarchitecture, and microfinite element analysis for estimated strength. The groups did not differ for age, pubertal stage, menarcheal age or physical activity. BMI and bone outcomes overall were intermediate in AAN compared with AN and HC. This applied to spine, total hip and femoral neck BMD measures and many distal tibial measures. However, the mean whole-body less head BMD Z-score did not differ between AAN and AN, and it was lower in both vs. HC. Similarly, many distal radius measures did not differ between AAN vs. AN or HC but were lower in AN than HC. Lower BMI, lean mass and bone age, older menarcheal age and longer illness duration correlated with greater impairment of bone outcomes. These data indicate that individuals with AAN overall have bone outcomes that are intermediate between AN and HC.

Endocrine complications of anorexia nervosa

An important component in the treatment of anorexia nervosa (AN) is the evaluation and management of its endocrine complications, including functional hypogonadotropic hypogonadism and increased fracture risk. The body's adaptive response to chronic starvation results in many endocrine abnormalities, most of which are reversible upon weight restoration. A multidisciplinary team with experience in treating patients with AN is critical to improving endocrine outcomes in patients with this disorder, including in women with AN who are interested in fertility. Much less is understood about endocrine abnormalities in men, as well as sexual and gender minorities, with AN. In this article, we review the pathophysiology and evidence-based recommendations for the treatment of endocrine complications in AN, as well as discuss the status of clinical research in this area.

Changes in trabecular bone score and bone density in female adolescents with anorexia nervosa: a longitudinal study

Impaired bone health is a common complication of anorexia nervosa (AN). We aimed to assess longitudinal changes in bone mineral density (BMD) and trabecular bone score (TBS), a measure of bone quality, in female adolescents with anorexia nervosa (AN). We conducted a retrospective longitudinal study of 41 female adolescents with AN who underwent two dual-energy X-ray absorptiometry (DXA) scans. Clinical data, including age, weight, height, body mass index (BMI), and DXA measurements were retrieved from the medical charts. Lumbar bone mineral apparent density (BMAD) was calculated to correct for size. Changes (Δ) in BMD, BMAD, and TBS were examined for correlations with clinical characteristics. Mean ages at the time of DXA scans were 14.8±1.9 and 16.8±2.0 years. There was a significant improvement in anthropometric parameters and DXA measurements at the second DXA scan. However, these values were still significantly lower than expected in the general population. The Δlumbar BMD Z-score was 0.3±0.7, the Δlumbar BMAD Z-score was 0.2±0.7 and the ΔTBS Z-score was 0.5±0.7. ΔTBS Z-score was positively correlated with Δheight Z-score, Δweight Z-score and ΔBMI Z-scores, and negatively correlated height Z-score, weight Z-score and TBS Z-scores at the first DXA scan (p<0.05). Δheight Z-score, ΔBMI Z-score and the progression from early to late puberty were identified as significant independent predictors of Δlumbar BMAD Z-score (p<0.05). During two years of treatment, both BMD and TBS increased significantly. Improvement in height and in weight status, and progression in puberty are predictors of improvement in BMD and TBS.

Physiologic Transdermal Estradiol Replacement Mimics Effects of Endogenous Estrogen on Bone Outcomes in Hypoestrogenic Women with Anorexia Nervosa

Background: While physiologic estrogen replacement results in increases in areal bone mineral density (aBMD) in hypoestrogenic adolescent girls and young adult women with AN, data are lacking regarding its impact on measures of volumetric BMD (vBMD), bone geometry, and structure. Methods: 23 young women with anorexia nervosa (AN) and 27 normal-weight healthy controls (HC) between 14−25 years old were followed for 12 months. AN participants received transdermal 17β-estradiol (continuously) with 10 days of cyclic oral progesterone (100 mg daily) every month for the study duration (AN-E+). DXA was used to measure aBMD and body composition, high resolution peripheral quantitative CT (HRpQCT) to assess vBMD, bone geometry and structure at the distal radius and tibia, and microfinite element analysis to estimate strength. Results: Groups did not differ for age. Median baseline BMI z-scores were −1.13 (−1.58, −0.38) in AN-E+ vs. 0.08 (−0.40, 0.84) in HC (p < 0.0001). For most HRpQCT parameters and strength estimates, young women with AN receiving physiologic estrogen replacement demonstrated similar changes over 12 months as did normoestrogenic HC. Additionally, radial cortical tissue mineral density, cortical vBMD, and failure load increased (p = 0.01; p = 0.02; p = 0.004 respectively) over 12 months in AN-E+ compared to HC. Conclusions: With physiologic estrogen replacement, bone accrual improved in AN to approximate changes observed in normoestrogenic controls followed without any intervention, with additional benefits observed for cortical tissue mineral density, cortical vBMD, and failure load at the radius in AN vs. controls. Thus, this strategy for estrogen replacement effectively mimics the effects of endogenous estrogen on bone structure and estimated strength.

The female athlete triad: review of current literature

PURPOSE OF REVIEW

Adolescence and young adulthood are a critical period in the life of women for optimizing long-term bone health. Young athletes lead a demanding lifestyle with increased dietary requirements to meet the robust demands of energy expenditure to maintain a state of energy balance. During a time of fast paced changes and unpredictable societal demands on young athletes, it is important to review the severe consequences of energy deficiency and options for adequate management.

RECENT FINDINGS

This review focuses on hormonal adaptations that occur in energy deficient female athletes that lead to menstrual irregularities and impaired bone health, increasing the risk for stress and other fractures. We also describe management strategies to mitigate the consequences of limited energy availability on bone and other outcomes.

SUMMARY

These strategies should help guide the management of young female athletes to prevent irreversible changes to their bone health. Identifying current knowledge should help increase awareness among medical providers, which can then be communicated to the sports community, parents, and athletes.

Aging of Skeletal Stem Cells

The skeletal system is generated and maintained by its progenitors, skeletal stem cells (SSCs), across the duration of life. Gradual changes associated with aging result in significant differences in functionality of SSCs. Declines in bone and cartilage production, increase of bone marrow adipose tissue, compositional changes of cellular microenvironments, and subsequent deterioration of external and internal structures culminate in the aged and weakened skeleton. The features and mechanisms of skeletal aging, and of its stem and progenitor cells in particular, are topics of recent investigation. The discovery of functionally homogeneous SSC populations with a defined cell surface phenotype has allowed for closer inspection of aging in terms of its effects on transcriptional regulation, cell function, and identity. Here, we review the aspects of SSC aging on both micro- and macroscopic levels. Up-to-date knowledge of SSC biology and aging is presented, and directions for future research and potential therapies are discussed. The realm of SSC-mediated bone aging remains an important component of global health and a necessary facet in our understanding of human aging.

Functional hypothalamic amenorrhea: Impact on bone and neuropsychiatric outcomes

Functional hypothalamic amenorrhea is a state of reversible hypogonadism common in adolescents and young women that can be triggered by energy deficit or emotional stress or a combination of these factors. Energy deficit may be a consequence of (i) reduced caloric intake, as seen in patients with eating disorders, such as anorexia nervosa, or (ii) excessive exercise, when caloric intake is insufficient to meet the needs of energy expenditure. In these conditions of energy deficit, suppression of the hypothalamic secretion of gonadotrophin-releasing hormone (with resulting hypoestrogenism) as well as other changes in hypothalamic-pituitary function may occur as an adaptive response to limited energy availability. Many of these adaptive changes, however, are deleterious to reproductive, skeletal, and neuropsychiatric health. Particularly, normoestrogenemia is critical for normal bone accrual during adolescence, and hypoestrogenemia during this time may lead to deficits in peak bone mass acquisition with longstanding effects on skeletal health. The adolescent years are also a time of neurological changes that impact cognitive function, and anxiety and depression present more frequently during this time. Normal estrogen status is essential for optimal cognitive function (particularly verbal memory and executive function) and may impact emotion and mood. Early recognition of women at high risk of developing hypothalamic amenorrhea and its timely management with a multidisciplinary team are crucial to prevent the severe and long-term effects of this condition.

Estrogen for the Treatment of Low Bone Mineral Density in Anorexia Nervosa

Anorexia nervosa is a disorder of chronic, self-induced negative energy balance which typically results in a low body weight. Functional hypothalamic amenorrhea is an adaptive response to states of negative energy balance and chronic undernutrition. A majority of women with anorexia nervosa are amenorrheic with resultant hypoestrogenemia, and longer durations of amenorrhea are associated with lower bone mineral density in this population. In this review, we highlight studies that have investigated the effects of estrogen replacement on bone mineral density in anorexia nervosa, including prospective and randomized studies that show no benefit to treatment with oral estrogen with respect to bone mineral density in either adolescent girls or women with anorexia nervosa. We also review data from a randomized, placebo-controlled study in adolescent girls and a prospective, open-label pilot study in women with anorexia nervosa suggesting that transdermal estrogen may have beneficial effects with respect to bone mineral density in this population.

Effect of Transdermal Estradiol and Insulin-like Growth Factor-1 on Bone Endpoints of Young Women With Anorexia Nervosa

CONTEXT

Anorexia nervosa (AN) is prevalent in adolescent girls and is associated with bone impairment driven by hormonal alterations in nutritional deficiency.

OBJECTIVE

To assess the impact of estrogen replacement with and without recombinant human insulin-like growth factor-1 (rhIGF-1) administration on bone outcomes.

DESIGN

Double-blind, randomized, placebo-controlled 12-month longitudinal study.

PARTICIPANTS

Seventy-five adolescent and young adult women with AN age 14 to 22 years. Thirty-three participants completed the study.

INTERVENTION

Transdermal 17-beta estradiol 0.1 mg/day with (i) 30 mcg/kg/dose of rhIGF-1 administered subcutaneously twice daily (AN-IGF-1+) or (ii) placebo (AN-IGF-1-). The dose of rhIGF-1 was adjusted to maintain levels in the upper half of the normal pubertal range.

MAIN OUTCOME MEASURES

Bone turnover markers and bone density, geometry, microarchitecture, and strength estimates.

RESULTS

Over 12 months, lumbar areal bone mineral density increased in AN-IGF-1- compared to AN-IGF-1+ (P = 0.004). AN-IGF-1+ demonstrated no improvement in areal BMD in the setting of variable compliance to estrogen treatment. Groups did not differ for 12-month changes in bone geometry, microarchitecture, volumetric bone mineral density (vBMD), or strength (and results did not change after controlling for weight changes over 12 months). Both groups had increases in radial cortical area and vBMD, and tibia cortical vBMD over 12 months. Levels of a bone resorption marker decreased in AN-IGF-1- (P = 0.042), while parathyroid hormone increased in AN-IGF-1+ (P = 0.019). AN-IGF-1- experienced irregular menses more frequently than did AN-IGF-1+, but incidence of all other adverse events did not differ between groups.

CONCLUSIONS

We found no additive benefit of rhIGF-1 administration for 12 months over transdermal estrogen replacement alone in this cohort of young women with AN.