Growth Hormone Therapy for Wasting in Cystic Fibrosis

Inclusion Criteria: * Ability to provide written informed consent and comply with study assessments for the full duration of the study. * Age \> 18 years * Cystic fibrosis, diagnosed by either sweat chloride or genetic testing * Less than 92% ideal body weight based on body mass index (BMI) of 22 for women and 23 for men * Moderate or better pulmonary function (Forced Expiratory Volume (FEV1) \>40% of predicted). * Agree to use an effective method of birth control to prevent pregnancy during the research study. Women should not nurse (breast feed) a baby while on this study because Nutropin AQ may enter breast milk and possibly harm the child. Exclusion Criteria: * Pregnancy (positive pregnancy test) prior enrollment in the study * Any other condition that the investigator believes would pose a significant hazard to the subject if the investigational therapy were initiated * Participation in another simultaneous medical investigation or trial * Pediatric patients * Active neoplasm * History of organ transplantation * Prader Willi Syndrome who are severely obese or have severe respiratory impairment * Patients with hepatic impairment resulting in abnormal coagulation studies (\>1.5 times normal reference range) * Poorly controlled diabetes as determined by a Hemoglobin A1c greater than or equal to 9.0%. * Individuals with electrocardiogram abnormality or cardiac pacing.