Safety Profile of Insulin Like Growth Factor-1 (IGF-I) Administration in Adolescents

The purpose of this study was to determine whether giving insulin like growth factor-I (IGF-I) to adolescent low weight girls is safe and whether this increases levels of bone formation markers.

Adolescents 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 I (IGF-I), the bone trophic factor made in the liver in response to growth hormone (GH), despite elevated levels GH. It is possible that deficiency of IGF-I, a hormone very important for the maintenance of skeletal integrity, may contribute to the severe osteopenia seen in AN. The physiologic effects of rhIGF-I treatment in adolescents with AN had not been studied. The goal of this proposal was to investigate the acute effects of rhIGF-I on bone metabolism in adolescent girls with AN. Specific Aim: It was hypothesized that adolescent AN patients, being IGF-I deficient, would respond to exogenously administered rhIGF-I with elevations in biochemical indices of bone turnover. Therefore, rhIGF-I was administered to AN patients by subcutaneous injection over 10 days with concomitant measurement of indices of bone turnover, and calcium regulatory hormones.

Adolescent girls with AN meeting inclusion criteria were administered recombinant human (rh) rhIGF-1 at a dose of 35-40 mcg/k twice daily by subcutaneous injections for a 7-10 day period.

Change in Levels of Insulin Like Growth Factor-1 (IGF-I) Following Recombinant Human (rh) IGF-1 Administration in Girls With Anorexia Nervosa

Change in Levels of N-terminal Propeptide of Type 1 Procollagen (P1NP) Following rhIGF-1 Administration in Girls With Anorexia Nervosa

Inclusion Criteria: Adolescent girls with anorexia nervosa 12-18 years old Exclusion Criteria: Pregnancy or nursing Hematocrit < 30%, K < 3 mmol/L Any illness (other than anorexia nervosa) known to affect bone and mineral metabolism such as diabetes, alcoholism, untreated hypo- or hyperthyroidism, or hyperparathyroidism History of use of any medicine, such as corticosteroids, known to affect bone density. Subjects who were on estrogen were still eligible to participate in the study.

Misra M, McGrane J, Miller KK, Goldstein MA, Ebrahimi S, Weigel T, Klibanski A. Effects of rhIGF-1 administration on surrogate markers of bone turnover in adolescents with anorexia nervosa. Bone. 2009 Sep;45(3):493-8. doi: 10.1016/j.bone.2009.06.002. Epub 2009 Jun 10.