Adolescents and young adults with anorexia nervosa (AN) are at high risk for low bone mineral density at a time when healthy adolescents are rapidly accruing bone, with implications for peak bone mass and fracture risk in later life. They are also deficient in insulin-like growth factor 1 (IGF-1), the bone trophic factor made in the liver in response to growth hormone (GH), despite elevated levels of growth hormone. It is possible that deficiency of insulin-like growth factor 1, a hormone very important for the maintenance of skeletal integrity, may contribute to the severe osteopenia seen in anorexia nervosa. The physiologic effects of recombinant human insulin-like growth factor 1 (rhIGF-1) treatment in adolescents and young adults with anorexia nervosa have not been studied. The goal of this proposal is to investigate the effects of recombinant human insulin-like growth factor 1 on bone density and bone microarchitecture in adolescent girls and young adult women with anorexia nervosa over a 6 month period. We hypothesize that adolescent and young adult anorexia nervosa patients, being insulin-like growth factor 1 deficient, will respond to exogenously administered recombinant human insulin-like growth factor 1 with elevations in biochemical indices of bone turnover and an increase in bone density and improvement in bone structure, or maintain bone density (in contrast to the decrease in bone density expected in adolescent girls and women with anorexia nervosa who are not treated).

Inclusion Criteria:

- Meet criteria for anorexia nervosa (AN) as described in the Diagnostic and Statistical Manual of Mental Disorders

Exclusion Criteria:

• Pregnant or nursing
• Hematocrit < 30%, K < 3 mmol/L
• Any illness (other than AN) known to affect bone and mineral metabolism such as diabetes, untreated hypo- or hyperthyroidism, or hyperparathyroidism
• History of use of any medicine, such as corticosteroids, known to affect bone density. Subjects who are on estrogen will still be eligible to participate in the study because our data in adult women with AN do not indicate deleterious effects of estrogen in patients receiving rhIGF-

For the adolescent arm, adverse event data was collected for 6 months. For the adult arm, adverse event data was collected for 1 year.

All subjects were assessed for any adverse events at screen, baseline, 1 month, 3 months, 4.5 months, and 6 months. The adult arm was subsequently assessed for any adverse events at 7 months, 9 months, and 12 months.