Is lifetime traumatic brain injury a risk factor for mild cognitive impairment in veterans compared to non-veterans?

Eur J Psychotraumatol. 2024;15(1):2291965. doi: 10.1080/20008066.2023.2291965. Epub 2024 Jan 4.

Abstract

Background: Traumatic brain injury (TBI) is prevalent in veterans and may occur at any stages of their life (before, during, or after military service). This is of particular concern, as previous evidence in the general population has identified TBI as a strong risk factor for mild cognitive impairment (MCI), a known precursor of dementia.Objectives: This study aimed to investigate whether exposure to at least one TBI across the lifetime was a risk factor for MCI in ageing UK veterans compared to non-veterans.Method: This cross-sectional study comprised of data from PROTECT, a cohort study comprising UK veterans and non-veterans aged ≥ 50 years at baseline. Veteran and TBI status were self-reported using the Military Service History Questionnaire (MSHQ) and the Brain Injury Screening Questionnaire (BISQ), respectively. MCI was the outcome of interest, and was defined as subjective cognitive impairment and objective cognitive impairment.Results: The sample population comprised of veterans (n = 701) and non-veterans (n = 12,389). TBI was a significant risk factor for MCI in the overall sample (OR = 1.21, 95% CI 1.11-1.31) compared to individuals without TBI. The prevalence of TBI was significantly higher in veterans compared to non-veterans (69.9% vs 59.5%, p < .001). There was no significant difference in the risk of MCI between veterans with TBI and non-veterans with TBI (OR = 1.19, 95% CI 0.98-1.45).Conclusion: TBI remains an important risk factor for MCI, irrespective of veteran status. The clinical implications indicate the need for early intervention for MCI prevention after TBI.

Antecedentes: El traumatismo encéfalocraneano (TEC) es frecuente en veteranos, el cual puede ocurrir en cualquier etapa de sus vidas (antes, durante o después del servicio militar). Esto es motivo de preocupación, ya que evidencia previa en la población general ha identificado al TEC como un fuerte factor de riesgo de Deterioro Cognitivo Leve (DCL), un precursor conocido de demencia.

Objetivo: Este estudio tuvo como objetivo investigar si la exposición a al menos un Traumatismo encéfalocraneano a lo largo de la vida era un factor de riesgo de Deterioro Cognitivo Leve en veteranos del Reino Unido en comparación con no veteranos.

Método: Este estudio de corte transversal incluyó datos de PROTECT, un estudio de cohorte que incluye a veteranos y no veteranos del Reino Unido de ≥50 años al inicio del estudio. El estatus de veterano y de Traumatismo encéfalocraneano (TEC) se auto-reportaron utilizando el Cuestionario de Historia de Servicio Militar (MSHQ, por sus siglas en inglés) y el Cuestionario de Detección de Traumatismo encéfalocraneano (BISQ, por sus siglas en inglés), respectivamente. El Deterioro Cognitivo Leve (DCL) fue el resultado de interés, definido como deterioro cognitivo subjetivo y deterioro cognitivo objetivo.

Resultados: La muestra poblacional incluyó a veteranos (n = 701) y no veteranos (n = 12.389). El Traumatismo encéfalocraneano (TEC) fue un factor de riesgo significativo de Deterioro Cognitivo Leve (DCL) en la muestra total (OR = 1.21, IC del 95% 1.11–1.31) en comparación con individuos sin TEC. La prevalencia de TEC fue significativamente mayor en veteranos en comparación con no veteranos (69.9% vs 59.5%, p < .001). No hubo diferencia significativa en el riesgo de DCL entre veteranos con TEC y no veteranos con TEC (OR = 1.19, IC del 95% 0.98–1.45).

Conclusión: El Traumatismo encéfalocraneano (TEC) continúa siendo un factor de riesgo significativo de Deterioro Cognitivo Leve (DCL), independiente del estatus de veterano. Las implicaciones clínicas sugieren la necesidad de intervenciones tempranas para la prevención de DCL después de un TEC.

Keywords: Traumatic brain injury; Traumatismo encéfalocraneano; ageing population; deterioro cognitivo leve; mild cognitive impairment; no veteranos; non-veterans; población envejeciendo; veteranos; veterans.

Plain language summary

Data from the PROTECT study, a longitudinal study comprising over 25,000 middle-aged and ageing adults in the UK, were used in this first UK comparative study to explore the association between a lifetime history of traumatic brain injury (TBI) and mild cognitive impairment (MCI) in UK veterans and non-veterans.Lifetime TBI was more prevalent in veterans compared to non-veterans. TBI events in military veterans could be attributed to non-military events.Exposure to a history of TBI irrespective of veteran status increased the risk of MCI by 21% compared to adults with no history of TBI.The risk of MCI did not significantly differ between veterans and non-veterans with TBI.

MeSH terms

  • Brain Injuries, Traumatic* / epidemiology
  • Brain Injuries, Traumatic* / psychology
  • Cognitive Dysfunction* / epidemiology
  • Cohort Studies
  • Cross-Sectional Studies
  • Humans
  • Risk Factors
  • Veterans* / psychology

Grants and funding

This study was funded as part of a PhD studentship by the Alzheimer’s Society (award no. 475 [AS-PhD-18b-002]). The PROTECT study was externally funded/supported by the National Institute of Health and Care Research, Exeter Biomedical Research Centre. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. The Family History of Neurological Disease Questionnaire was funded in part by the Alzheimer’s Research UK South West Network.