Physical Functional Impairment and the Risk of Incident Mild Cognitive Impairment in an Observational Study of World Trade Center Responders

Abstract

Background and Objectives:Posttraumatic stress disorder (PTSD) has been linked to increased risk of cognitive dysfunction and physical functional impairment (PFI). The objective of this prospective cohort study was to examine whether PFI was associated with increased risk of incident mild cognitive impairment (MCI) among World Trade Center (WTC) responders with PTSD. We hypothesized that responders with PTSD would have an elevated risk of incident MCI, and that PFI would mediate this increase.Methods:We examined responder participants in the WTC Aging Study whose baseline physical assessments were completed 5/2016–4/2017 and were followed up at least once prior to 12/2019. Those without complete demographic, medical, or behavioral data were excluded. PFI was assessed using measures of upper body strength (maximal handgrip strength (HGS)) and lower extremity physical functioning (Short Physical Performance Battery). PTSD was rated using a diagnostic interview and symptom checklist; MCI and dementia were assessed using the Montreal Cognitive Assessment and diagnosed using NIA-AA criteria. Group differences and longitudinal comparisons were examined. Cox proportional hazards models evaluated time to incident MCI and conversion to dementia. Mediation analysis examined whether PFI mediated associations between PTSD and MCI.Results:Within the sample of 2,687 WTC responders, 324 (12.06%, 95% C.I. = [10.83-13.29]) had lower extremity PFI. Responders with lower extremity PFI were older, had lower education and higher body mass, and were at higher risk of pulmonary embolisms and PTSD. Responders with lower extremity PFI demonstrated lower baseline cognition and had increased hazards of MCI (aHR=1.55 [95% C.I. 1.21, 1.98]); those with MCI converted to dementia more rapidly than those without PFI (2.73 [1.38-5.39] P=0.004). Additionally, each standard deviation decrease in HGS was associated with increased hazards of developing MCI (aHR=1.35 [95% C.I. 1.10, 1.66]). A mediation model suggested PFI played an intermediary role in the relationship between PTSD and MCI.Discussion:WTC responders with PFI demonstrated worse cognitive and behavioral outcomes, and PFI played an intermediary role in the relationship between PTSD and incident MCI, suggesting PFI may be an early indicator of MCI in responders with PTSD. Regular monitoring of PFI should be considered among PTSD populations.

Does mild cognitive impairment accelerate age-related changes in physical function and body composition? A three-year longitudinal follow-up study

“…Having MCI or dementia is associated with greater physical decline compared to older people with normal cognition [23]. Older adults with MCI converted to dementia more rapidly than those without physical functional impairment [24]. Older adults with MCI may develop Alzheimer's disease (AD) in approximately 3.5 years, and both cognitive and physical function may decline gradually after AD onset [25].…”

Cognitive intervention using Montessori and DementiAbility for people with mild cognitive impairment

“…Pellecchia et al found that Physical Functional Impairment (PFI) played an intermediary role in the relationship between Post-Traumatic Stress Disorder (PTSD) and Mild Cognitive Impairment (MCI). 7 The researchers mentioned that PFI may be the first sign of MCI in people with PTSD. Less physical movement increases the chances of diseases, disability, hospitalization, poorer quality of life, and death.…”