IGF-1 Therapy in Patients With Cystic Fibrosis

Inclusion Criteria: * Diagnosis of cystic fibrosis as proven by either sweat chloride or DNA analysis. * Age \>= 18 yr. * Tanner stage: Femake Breasts: 4-5 Male Genitalia: 4-5 Exclusion criteria: * Hemoglobin A1C \> 8.5 % * Diabetic retinopathy * Obstructive sleep apnea * Respiratory failure requiring mechanical ventilation. * Status post pulmonary transplantation. * Concurrent or recent (within past 6 months) receipt of human growth hormone. * History of adverse side effects to growth hormone other than carbohydrate intolerance. * Pregnancy or attempting pregnancy. * Women who are breast feeding. * Sexually active women who refuse to use or are incapable of responsibly using reliable contraception. * Proven non compliance with medical regimens. * Inability or refusal to take subcutaneous injections. * Known allergy to components in the IGF-I preparation.