Growth Hormone Replacement Therapy for Retried Professional Football Players

Inclusion Criteria: * The subject is willing to provide a signed and dated informed consent indicating that he understands the purpose and procedures required for the study and is willing to participate in the study. * Former NFL player * At least one year since retirement from football * Less than 76 years of age * Diagnosis of GHD on clinical grounds by a neurologist and an endocrinologist GHD Exclusion Criteria: * History of pre-existing brain disease other than concussion or TBI * History of a premorbid disabling condition that interferes with outcome assessments * Contraindication to GH therapy * Type I and II Diabetes mellitus * Active malignant disease * Acute critical illness, heart failure, or acute respiratory failure * Subjects who are deficient in cortisol, testosterone or thyroid at screening will be excluded until hormone abnormalities have been corrected.