RESUMEN
OBJECTIVE: Acute hypogonadotropic hypogonadism (AHH) occurs frequently after TBI, as does chronic hypogonadotropic hypogonadism. However, AHH and persistent hypogonadotropic hypogonadism (PHH) after TBI are not well studied. The objective of this study was to characterize longitudinal hormone profiles and the impact of AHH and PHH on outcome. METHODS: In this prospective cohort study, men with severe TBI (n = 38) had serum gonadal and gonadotropic hormones measured during weeks 1-52 post-injury. AHH, PHH and/or early resolving hypogonadotropic hypogonadism (ERHH) were based on temporal hormone assessments. PHH and hormone profiles were then compared to multiple outcome measures 6-12 months post-TBI. RESULTS: AHH affected 100% of the population, while 37% subsequently developed PHH. Acute testosterone (TEST) and estradiol/testosterone (E2/TEST) ratios were associated with PHH and outcome. Over time, post-acute TEST and E2 levels for the ERHH group approached normal range, while levels for the PHH group remained low. Post-acute gonadotrophin levels were within the normal range for both groups. PHH, along with lower post-acute TEST and E2 profiles, was associated with worse functional and cognitive outcomes at 6 and 12 months post-injury. CONCLUSIONS: These results support screening for post-acute secondary hypogonadism and further research to assess the mechanisms underlying PHH and associated functional and cognitive deficits.
Asunto(s)
Lesiones Encefálicas/sangre , Lesiones Encefálicas/psicología , Trastornos del Conocimiento/sangre , Cognición , Estradiol/sangre , Hipogonadismo/sangre , Adolescente , Adulto , Anciano , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/fisiopatología , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/fisiopatología , Estradiol/biosíntesis , Escala de Consecuencias de Glasgow , Humanos , Hipogonadismo/etiología , Hipogonadismo/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estrés Fisiológico , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Experimental traumatic brain injury (TBI) studies report the neuroprotective effects of female sex steroids on multiple mechanisms of injury, with the clinical assumption that women have hormonally mediated neuroprotection because of the endogenous presence of these hormones. Other literature indicates that testosterone may exacerbate injury. Further, stress hormone abnormalities that accompany critical illness may both amplify or blunt sex steroid levels. To better understand the role of sex steroid exposure in mediating TBI, we 1) characterized temporal profiles of serum gonadal and stress hormones in a population with severe TBI during the acute phases of their injury; and 2) used a biological systems approach to evaluate these hormones as biomarkers predicting global outcome. The study population was 117 adults (28 women; 89 men) with severe TBI. Serum samples (n=536) were collected for 7 days post-TBI for cortisol, progesterone, testosterone, estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Hormone data were linked with clinical data, including acute care mortality and Glasgow Outcome Scale (GOS) scores at 6 months. Hormone levels after TBI were compared to those in healthy controls (n=14). Group based trajectory analysis (TRAJ) was used to develop temporal hormone profiles that delineate distinct subpopulations in the cohort. Structural equations models were used to determine inter-relationships between hormones and outcomes within a multivariate model. Compared to controls, acute serum hormone levels were significantly altered after severe TBI. Changes in the post-TBI adrenal response and peripheral aromatization influenced hormone TRAJ profiles and contributed to the abnormalities, including increased estradiol in men and increased testosterone in women. In addition to older age and greater injury severity, increased estradiol and testosterone levels over time were associated with increased mortality and worse global outcome for both men and women. These findings represent a paradigm shift when thinking about the role of sex steroids in neuroprotection clinically after TBI.