Low trabecular bone score in adolescent female inpatients with anorexia nervosa

Trabecular bone score (TBS) is an emerging technology that provides information regarding bone microarchitecture. A recent study showed that in healthy girls normal TBS (≥1.35) was achieved within the first year post-menarche. The aims of our study was to assess TBS in adolescents with anorexia nervosa (AN) and to evaluate correlations with clinical, laboratory and densitometric variables.

A cohort study of 208 adolescent females (mean age 15.6 ± 1.8 y) hospitalized because of AN between 2003 and 2017 was retrospectively assessed. Demographic and clinical data, including age, weight, height, body mass index (BMI), laboratory parameters and bone mineral density (BMD) measurements by dual-energy X-ray absorptiometry (DXA) were retrieved from the medical charts. Bone mineral apparent density (BMAD) was calculated for each participant. TBS was assessed by reanalyzing DXA spinal images.

Mean TBS was 1.308 ± 0.083, lower than the values previously described in healthy adolescents (p < 0.001). Compromised microarchitecture was found in 17 participants (8.2%) and partially compromised in 123 (59.1%). TBS was significantly correlated with age, weight standard deviation score (SDS), BMI SDS, BMD measurements of the lumbar spine and total body, BMAD, BMAD Z-score, luteinizing hormone (LH) and 17b-estradiol (E2) level, and was negatively correlated with cortisol (p = 0.017). Participants with regular menstruation or secondary amenorrhea had higher TBS than participants who were pre-menarche or with primary amenorrhea (p < 0.001). A stepwise linear regression analysis identified BMD L1-4 Z-score and log E2 as independent predictors of TBS.

TBS of adolescent females with AN was found to be lower than TBS of healthy adolescents. Prospective longitudinal studies should be undertaken to investigate whether recovery may result in correction of bone microarchitecture.