Skeletal outcomes by peripheral quantitative computed tomography and dual-energy X-ray absorptiometry in adolescent girls with anorexia nervosa

Abstract

Summary We conducted the first comparison of dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) outcomes in adolescent girls with anorexia nervosa. We observed deficits in bone density by both tools. pQCT assessments were associated with many of the same clinical parameters as have been previously established for DXA. Introduction Adolescents with anorexia nervosa (AN) commonly exhibit bone loss, but effects on bone geometry are less clear. We compared measures obtained by DXA and pQCT in girls with AN. Methods Seventy females (age 15.5 ± 1.9 years ) with AN and 132 normal-weighted controls underwent tibial measures by pQCT including trabecular volumetric bone mineral density (vBMD) at the 3 % site, cortical vBMD and dimensions at the 38 % site, and muscle cross-sectional area (CSA) at the 66 % site. Participants with AN also underwent standard DXA measures. Independent t tests compared the pQCT results, while Pearson coefficient assessed correlations among DXA and pQCT measures. Results Trabecular vBMD Z-scores were lower in AN compared to controls (AN −0.31 ± 1.42 vs +0.11 ± 1.01, p = 0.01) and cortical vBMD Z-scores were higher (AN +0.18 ± 0.92 vs −0.50 ± 0.88, p < 0.001). Trabecular vBMD and cortical CSA Z-scores positively correlated with DXA BMD Z-scores (r range 0.57–0.82, p < 0.001). Markers of nutritional status positively correlated with Z-scores for trabecular vBMD, cortical CSA, section modulus, and muscle CSA (p < 0.04 for all). Conclusions This study is the first to compare DXA and pQCT measurements in adolescent girls with AN. We observed deficits in BMD by both DXA and pQCT. pQCT assessments correlated well with DXA bone and body composition measures and were associated with many of the same clinical parameters and disease severity markers as have been previously established for DXA. The differences in cortical vBMD merit further study.

Eating disorders and bone metabolism in women

“…However, one study assessed the distal tibia using pQCT, and reported lower trabecular, but higher cortical vBMD, in young women with AN compared with controls. AN girls in this study had a mean percent ideal body weight of 91%, and thus were not as low weight as in other studies [29*]. …”

Assessment of fracture risk in women with eating disorders: The utility of dual‐energy x‐ray absorptiometry (DXA)—Clinical cohort study

“…Both the absolute BMD‐deficit and prevalence of low z‐score (below −2) in hip and lumbar spine, are similar to the findings in others cohorts comparable on age and duration of disease (Bachmann et al, ; Grinspoon et al, ; Hofman, Landewe‐Cleuren, Wojciechowski, & Kruseman, ; Winston, Alwazeer, & Bankart, ). Furthermore, patients with similar age at debut of disease and BMI at baseline, but with shorter duration of disease, are reported to have higher BMD (DiVasta et al, ; Levy‐Shraga et al, ; Misra et al, ). Thus, our findings support the notion that the adverse effect of malnutrition on bone progresses with increasing duration of disease.…”

Evolutionary Perspectives on the Developing Skeleton and Implications for Lifelong Health

“…Nutritional status in terms of extremes of underweight and overweight have adverse consequences for bone accretion and development of optimal bone strength. Adolescents with anorexia have low bone density and reduced strength compared to normal weight peers, and these effects can be long lasting (79,80). At the other end of the spectrum, children with obesity have greater bone mineral content and density and greater cortical thickness than non-obese children (81).…”