Incidence of mild cognitive impairment in World Trade Center responders: Long‐term consequences of re‐experiencing the events on 9/11/2001

Abstract

Objective This study examined whether World Trade Center (WTC) exposures and chronic posttraumatic stress disorder (PTSD) were associated with incidence of mild cognitive impairment (MCI) in a longitudinal analysis of a prospective cohort study of WTC responders. Methods Incidence of MCI was assessed in a clinical sample of WTC responders (N = 1800) who were cognitively intact at baseline assessment. Crude incidence rates were calculated and compared to population estimates using standardized incidence ratios. Multivariable analyses used Cox proportional‐hazards regression. Results Responders were 53.1 years old (SD = 7.9) at baseline. Among eligible cognitively intact responders, 255 (14.2%) developed MCI at follow‐up. Incidence of MCI was higher than expected based on expectations from prior published research. Incidence was higher among those with increased PTSD symptom severity, and prolonged exposure was a risk factor in apolipoprotein‐ε4 carriers. Conclusions PTSD and prolonged WTC exposures were associated with increased incidence of MCI in WTC responders, results that may portend future high rates of dementia in WTC‐exposed responders.

Molecular linkage between post-traumatic stress disorder and cognitive impairment: a targeted proteomics study of World Trade Center responders

“…Prior studies have shown that chronic PTSD in the responders to the World Trade Center disaster is associated with systemic and neuropsychiatric conditions including MCI 30,31 . Furthermore, in some instances, we demonstrated that not only was there an association, but that PTSD helps to mediate the development and chronicity of these conditions, and may be linked to possible early dementia 32 .…”

Pathway Analysis for Plasma β-Amyloid, Tau and Neurofilament Light (ATN) in World Trade Center Responders at Midlife

“…These responders are now in their mid-50s, with the expected signs of senescence having already commenced. Considering the expected risks surrounding the aging process, prior work has noted that, compared with population norms, responders have a high prevalence of cognitive impairment at baseline [27] and incidence of mild cognitive impairment at follow-up [28]. Additionally, responders report greater memory dysfunction [7], and exhibit poor muscular strength [4], with an increased risk of physical functional limitations in neuro-associated movements [1].…”

World Trade Center Health Program: First Decade of Research

“…In another study of responders, the authors found an association between increased time working on-site and lower cognitive functioning [ 149 ]. In a longitudinal study the responder analyses confirmed this result among responders carrying the apolipoprotein-4 genetic risk allele (HR = 3.89, 95% 1.79, 8.46) that is believed to cause blood–brain barrier dysregulation [ 154 ]. Still, there is far less evidence supporting this pathway and it is difficult to disentangle the effects from environmental exposures and PTSD.…”

“…These findings were confirmed in a subsequent study, which also provided evidence of poorer cognitive functioning among WTC responders compared to general population norms [ 149 ]. Similarly, a large longitudinal study of a sample of WTC responders ( n = 1800) found an association between PTSD symptom severity and increased risk of cognitive impairment (hazard ratio, HR = 2.67, 95% CI: 1.33, 5.37) [ 154 ]. There are some results suggesting neurodegenerative effects.…”