The Effects of Anorexia Nervosa on Bone Metabolism in Female Adolescents

Osteopenia is a frequent, often persistent, complication of anorexia nervosa (AN) in adolescent girls and occurs during a critical time in bone development.Little is known about bone metabolism in this patient population.Therefore, we measured bone density (BMD) and body composition by dual energy x-ray absorptiometry, nutritional status, bone turnover, calcium, and hormonal status in 19 adolescent girls with AN (mean Ϯ SEM, 16.0 Ϯ 0.4 yr) and 19 bone age-matched controls.The mean duration of AN was 19 Ϯ 5 months.Spinal (L1-L4) osteopenia was common in AN.Lumbar anterioposterior BMD was more than 1 SD below the mean in 42% of patients, and lateral spine BMD was more than 1 SD below in 63% of patients compared with controls.Lean body mass significantly predicted lumbar bone mineral content (r ϭ 0.75; P Ͻ 0.0001) in controls only.In AN, duration of illness was the most significant predictor of spinal BMD (lumbar: r ϭ Ϫ0.44; P ϭ 0.06; lateral: r ϭ Ϫ0.59; P ϭ 0.008).AN adolescents with mature BA (15 yr and greater) were hypogonadal [estradiol, 16.2 Ϯ 1.9 vs. 23.3Ϯ 1.6 pg/mL (P ϭ 0.01); free testosterone, 0.70 Ϯ 0.17 vs. 1.36 Ϯ 0.14 pg/mL (P ϭ 0.01)] although dehydroepiandrosterone sulfate and urinary free cortisol levels did not differ.Leptin levels were Subjects and Methods SubjectsWe studied 38 Caucasian adolescent girls, 19 with AN, and 19 healthy adolescents.The AN patients were 12.8 -18.5 yr of age.All met DSM IV