Journal Article

Alterations of the GH/IGF-I Axis and Gut Microbiome after Traumatic Brain Injury: A New Clinical Syndrome?

Yuen, Kevin C J, Masel, Brent E, Sheffield-Moore, Melinda, Urban, Randall J, Reifschneider, Kent L, Pyles, Richard B

2020

Overview

Pituitary dysfunction with abnormal growth hormone (GH) secretion and neurocognitive deficits are common consequences of traumatic brain injury (TBI). Recognizing the comorbidity of these symptoms is of clinical importance; however, efficacious treatment is currently lacking. A review of studies in PubMed published between January 1980 to March 2020 and ongoing clinical trials was conducted using the search terms \"growth hormone,\" \"traumatic brain injury,\" and \"gut microbiome.\" Increasing evidence has implicated the effects of TBI in promoting an interplay of ischemia, cytotoxicity, and inflammation that renders a subset of patients to develop postinjury hypopituitarism, severe fatigue, and impaired cognition and behavioral processes. Recent data have suggested an association between abnormal GH secretion and altered gut microbiome in TBI patients, thus prompting the description of a hypothesized new clinical syndrome called \"brain injury associated fatigue and altered cognition.\" Notably, these patients demonstrate distinct characteristics from those with GH deficiency from other non-TBI causes in that their symptom complex improves significantly with recombinant human GH treatment, but does not reverse the underlying mechanistic cause as symptoms typically recur upon treatment cessation. The reviewed data describe the importance of alterations of the GH/insulin-like growth factor I axis and gut microbiome after brain injury and its influence in promoting neurocognitive and behavioral deficits in a bidirectional relationship, and highlight a new clinical syndrome that may exist in a subset of TBI patients in whom recombinant human GH therapy could significantly improve symptomatology. More studies are needed to further characterize this clinical syndrome.

• Publisher: Oxford University Press
• Subject: Brain / Brain Injuries, Traumatic - drug therapy / Brain Injuries, Traumatic - epidemiology / Brain Injuries, Traumatic - metabolism / Brain Injuries, Traumatic - microbiology / Clinical trials / Cognition / Comorbidity / Cytotoxicity / Digestive system / Fatigue / Gastrointestinal Microbiome - physiology / Growth hormones / Gut microbiota / Human Growth Hormone - metabolism / Human Growth Hormone - therapeutic use / Humans / Hypopituitarism / Hypopituitarism - drug therapy / Hypopituitarism - epidemiology / Hypopituitarism - metabolism / Hypopituitarism - microbiology / Injuries / Insulin / Insulin-like growth factor I / Insulin-Like Growth Factor I - metabolism / Intestinal microflora / Ischemia / Microbiomes / Microbiota / Patients / Pituitary / Secretion / Signal Transduction - physiology / Somatotropin / Syndrome / Traumatic brain injury / Treatment Outcome