We would like to ascertain the prevalence of hypopituitarism after combat-related TBI. This will lead to enhanced awareness, recognition, and treatment of hypopituitarism, which can have life-saving ramifications and enhance quality of life and rehabilitation efforts in our combat veterans.

The prevalence of hypopituitarism after combat-related traumatic brain injury (TBI) is currently unknown. Recent civilian data on TBI show the prevalence of any pituitary hormone deficiency is as high as 80% after 12 months. While the military prevalence of hypopituitarism can be extrapolated from civilian data, a major limitation is the notably different mechanism of injury (i.e., blast) for military personnel compared to civilians (i.e., assaults, traffic accidents and falls). Little is known about the effect of shockwaves from a blast injury on central nervous system tissue, and due to the unique nature of blast-related TBI, the prevalence of pituitary dysfunction in affected service members may significantly differ from nonmilitary subjects in prior studies.

Inclusion Criteria:

• Combat veterans who are 3 or 6 months post combat-related TBI and age 18yrs or older
• Must demonstrate capacity for informed consent
• Must be DEERS eligible (Military healthcare beneficiary)

Exclusion Criteria:

• Pregnancy (to be assessed by urine HCG)
• Use of hormonal contraceptives
• Chronic oral or intravenous glucocorticoids
• Use of hormonal therapy to include estrogen and testosterone
• Prior diagnosis of hypopituitarism prior to combat related TBI

Male and female combat veterans age 18 years and older with the diagnosis of Traumatic Brain Injury that occurred 3 and 6 months prior to enrollment.