Deficits in volumetric bone mineral density, bone microarchitecture, and estimated bone strength in women with atypical anorexia nervosa compared to healthy controls.

OBJECTIVE: Anorexia nervosa is associated with low bone mineral density (BMD) and deficits in bone microarchitecture and strength. Low BMD is common in atypical anorexia nervosa, in which criteria for anorexia nervosa are met except for low weight. We investigated whether women with atypical anorexia nervosa have deficits in bone microarchitecture and estimated strength at the peripheral skeleton. METHOD: Measures of BMD and microarchitecture were obtained in 28 women with atypical anorexia nervosa and 27 controls, aged 21-46 years. RESULTS: Mean tibial volumetric BMD, cortical thickness, and failure load were lower, and radial trabecular number and separation impaired, in atypical anorexia nervosa versus controls (p < .05). Adjusting for weight, deficits in tibial cortical bone variables persisted (p < .05). Women with atypical anorexia nervosa and amenorrhea had lower volumetric BMD and deficits in microarchitecture and failure load versus those with eumenorrhea and controls. Those with a history of overweight/obesity or fracture had deficits in bone microarchitecture versus controls. Tibial deficits were particularly marked. Less lean mass and longer disease duration were associated with deficits in high-resolution peripheral quantitative computed tomography (HR-pQCT) variables in atypical anorexia nervosa. DISCUSSION: Women with atypical anorexia nervosa have lower volumetric BMD and deficits in bone microarchitecture and strength at the peripheral skeleton versus controls, independent of weight, and particularly at the tibia. Women with atypical anorexia nervosa and amenorrhea, less lean mass, longer disease duration, history of overweight/obesity, or fracture history may be at higher risk. This is salient as deficits in HR-pQCT variables are associated with increased fracture risk. PUBLIC SIGNIFICANCE: Atypical anorexia nervosa is a psychiatric disorder in which psychological criteria for anorexia nervosa are met despite weight being in the normal range. We demonstrate that despite weight in the normal range, women with atypical anorexia nervosa have impaired bone density, structure, and strength compared to healthy controls. Whether this translates to an increased risk of incident fracture in this population requires further investigation.

Association between muscle mass and insulin sensitivity independent of detrimental adipose depots in young adults with overweight/obesity.

BACKGROUND/OBJECTIVE: Less muscle mass has been associated with greater insulin resistance, but whether the association is independent of deleterious adipose depots in young adults with overweight/obesity who are at high risk for type 2 diabetes (T2DM) but are otherwise metabolically healthy is not known. The objective of this study was to determine whether muscle mass is independently associated with insulin sensitivity (IS) in young adults with overweight/obesity. SUBJECTS/METHODS: Cross-sectional Clinical Research Center study of 132 adults, 21-45yo, BMI ≥ 25 kg/m2 and metabolically healthy without T2DM. Primary independent variable: percent ideal appendicular lean mass (ALM) calculated as measured ALM divided by predicted ALM for age, weight, and height, calculated using validated NHANES data-based equation. Primary dependent variable: IS by Matsuda index. RESULTS: Mean age was 34.3 ± 6.8 years, and mean BMI 35.8 ± 5.8 kg/m2 (mean ± SD). Individuals in the highest % ideal ALM tertile had mean IS 45% higher than the lowest tertile [6.94 ± 0.85 vs 4.80 ± 0.56 (mean ± SEM), p = 0.008] (sex interaction p = 0.003). Men in the highest % ideal ALM tertile had mean IS twice the lowest tertile (5.47 ± 0.68 vs 2.68 ± 0.34, p = 0.001), which remained significant controlling for visceral/subcutaneous and intermuscular adipose tissue, and intramyocellular and intrahepatic lipids (p = 0.03). The association was not significant in women. CONCLUSIONS: Muscle mass is associated with IS independent of detrimental adipose depots in young men with overweight/obesity, at risk for T2DM but currently metabolically healthy. Muscle mass relative to sex, age, weight, and height-specific norms may be used to ascertain individual T2DM risk associated with low muscle mass.

Bone mineral density and estimated hip strength in men with anorexia nervosa, atypical anorexia nervosa and avoidant/restrictive food intake disorder.

OBJECTIVE: Few bone mineral density (BMD) data are available in men with anorexia nervosa (AN), and none in those with atypical AN (ATYP) (AN psychological symptoms without low weight) or avoidant/restrictive food intake disorder (ARFID) (restrictive eating without AN psychological symptoms). We investigated the prevalence and determinants of low BMD and estimated hip strength in men with these disorders. DESIGN: Cross-sectional: two centres. PATIENTS: A total of 103 men, 18-63 years: AN (n = 26), ARFID (n = 11), ATYP (n = 18), healthy controls (HC) (n = 48). MEASUREMENTS: Body composition, BMD and estimated hip strength (section modulus and buckling ratio) by DXA (Hologic). Serum 25OH vitamin D was quantified, as was daily calcium intake in a subset of subjects. RESULTS: Mean BMI was lowest in AN and ARFID, higher in ATYP and highest in HC (AN 14.7 ± 1.8, ARFID 15.3 ± 1.5, ATYP 20.6 ± 2.0, HC 23.7 ± 3.3 kg/m2 ) (P < 0.0005). Mean BMD Z-scores at spine and hip were lower in AN and ARFID, but not ATYP, than HC (postero-anterior (PA) spine AN -2.05 ± 1.58, ARFID -1.33 ± 1.21, ATYP -0.59 ± 1.77, HC -0.12 ± 1.17) (P < 0.05). 65% AN, 18% ARFID, 33% ATYP and 6% HC had BMD Z-scores <-2 at ≥1 site (AN and ATYP vs HC, P < 0.01). Mean section modulus Z-scores were lower in AN than HC (P < 0.01). Lower BMI, muscle mass and vitamin D levels (R = 0.33-0.64), as well as longer disease duration (R = -0.51 to -0.58), were associated with lower BMD (P < 0.05). CONCLUSIONS: Men with AN, ARFID and ATYP are at risk for low BMD. Men with these eating disorders who are low weight, or who have low muscle mass, long illness duration and/or vitamin D deficiency, may be at particularly high risk.

Denosumab increases spine bone density in women with anorexia nervosa: a randomized clinical trial.

Objective: Anorexia nervosa is complicated by high bone resorption, low bone mineral density (BMD), and increased fracture risk. We investigated whether off-label antiresorptive therapy with denosumab increases BMD in women with anorexia nervosa. Design: Twelve-month, randomized, double-blind, placebo-controlled study. Methods: Thirty ambulatory women with anorexia nervosa and areal BMD (aBMD) T-score <-1.0 at ≥1 sites were randomized to 12 months of denosumab (60 mg subcutaneously q6 months)(n = 20) or placebo (n = 10). Primary end point was postero-anterior (PA) lumbar spine aBMD by dual-energy x-ray absorptiometry. Secondary end points included femoral neck aBMD, tibia and radius volumetric BMD and bone microarchitecture by high-resolution peripheral quantitative CT, tibia and radius failure load by finite element analysis (FEA), and markers of bone turnover. Results: Baseline mean (±s.d.) age (29 ± 8 (denosumab) vs 29 ± 7 years (placebo)), BMI (19.0 ± 1.7 vs 18.0 ± 2.0 kg/m2), and aBMD (PA spine Z-score -1.6±1.1 vs -1.7±1.4) were similar between groups. PA lumbar spine aBMD increased in the denosumab vs placebo group over 12 months (P = 0.009). The mean (95% CI) increase in PA lumbar spine aBMD was 5.5 (3.8-7.2)% in the denosumab group and 2.2 (-0.3-4.7)% in the placebo group. The change in femoral neck aBMD was similar between groups. Radial trabecular number increased, radial trabecular separation decreased, and tibial cortical porosity decreased in the denosumab vs placebo group (P ≤ 0.006). Serum C-terminal telopeptide of type I collagen and procollagen type I N-terminal propeptide decreased in the denosumab vs placebo group (P < 0.0001). Denosumab was well tolerated. Conclusions: Twelve months of antiresorptive therapy with denosumab reduced bone turnover and increased spine aBMD, the skeletal site most severely affected in women with anorexia nervosa.

Sequential Therapy With Recombinant Human IGF-1 Followed by Risedronate Increases Spine Bone Mineral Density in Women With Anorexia Nervosa: A Randomized, Placebo-Controlled Trial.

Anorexia nervosa is complicated by low bone mineral density (BMD) and increased fracture risk associated with low bone formation and high bone resorption. The lumbar spine is most severely affected. Low bone formation is associated with relative insulin-like growth factor 1 (IGF-1) deficiency. Our objective was to determine whether bone anabolic therapy with recombinant human (rh) IGF-1 used off-label followed by antiresorptive therapy with risedronate would increase BMD more than risedronate or placebo in women with anorexia nervosa. We conducted a 12-month, randomized, placebo-controlled study of 90 ambulatory women with anorexia nervosa and low areal BMD (aBMD). Participants were randomized to three groups: 6 months of rhIGF-1 followed by 6 months of risedronate ("rhIGF-1/Risedronate") (n = 33), 12 months of risedronate ("Risedronate") (n = 33), or double placebo ("Placebo") (n = 16). Outcome measures were lumbar spine (1° endpoint: postero-anterior [PA] spine), hip, and radius aBMD by dual-energy X-ray absorptiometry (DXA), and vertebral, tibial, and radial volumetric BMD (vBMD) and estimated strength by high-resolution peripheral quantitative computed tomography (HR-pCT) (for extremity measurements) and multi-detector computed tomography (for vertebral measurements). At baseline, mean age, body mass index (BMI), aBMD, and vBMD were similar among groups. At 12 months, mean PA lumbar spine aBMD was higher in the rhIGF-1/Risedronate (p = 0.03) group and trended toward being higher in the Risedronate group than Placebo. Mean lateral lumbar spine aBMD was higher, in the rhIGF-1/Risedronate than the Risedronate or Placebo groups (p < 0.05). Vertebral vBMD was higher, and estimated strength trended toward being higher, in the rhIGF-1/Risedronate than Placebo group (p < 0.05). Neither hip or radial aBMD or vBMD, nor radial or tibial estimated strength, differed among groups. rhIGF-1 was well tolerated. Therefore, sequential therapy with rhIGF-1 followed by risedronate increased lateral lumbar spine aBMD more than risedronate or placebo. Strategies that are anabolic and antiresorptive to bone may be effective at increasing BMD in women with anorexia nervosa. © 2021 American Society for Bone and Mineral Research (ASBMR).