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

Sean A.P Clouston,Erica D Diminich,Roman Kotov,Robert H Pietrzak,Marcus Richards,Avron Spiro,Yael Deri,Melissa Carr,Xiaohua Yang,Sam Gandy,Mary Sano,Evelyn J Bromet,Benjamin J Luft

doi:10.1016/j.dadm.2019.07.006

Abstract

ObjectiveThis 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. MethodsIncidence 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. ResultsResponders 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. ConclusionsPTSD 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.

Highlights

Keywords: 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
We hypothesized that incidence of MCI would be more common in WTC responders than in estimates from the general population and that PTSD symptom severity and WTC exposure duration would be associated with increased risk of incident MCI
Analyses of the likelihood of attrition revealed that those who were cognitively impaired at baseline were more likely to lack a follow-up cognitive assessment (RR 5 1.24, 95% CI 5 [1.08–1.42], P 5 .002) and revealed that among those who were cognitively normal, that having a Montreal Cognitive Assessment (MoCA), 26 was associated with loss to follow-up (RR 5 1.17, 95% CI 5 [1.02–1.34], P 5 .028)

Summary

Introduction

The events following the attacks on the World Trade Center (WTC) on September 11, 2001, were cataclysmic The impacts of these exposures, and their known sequelae, on mental and physical health, remain largely unknown. Research studies of WTC responders have found impairments in cognitive and physical functioning in this population [16,17,18], which is concentrated among responders reporting high levels of chronic intrusive re-experiencing stress. Prior research has been limited to cross-sectional association studies This is the first study to longitudinally assess the relationship between PTSD and the development of mild cognitive impairment (MCI). In 2014, SBU began the first and only prospective study to date to assess indicators of aging in WTC responders by incorporating cognitive assessments into the monitoring visit [18]. Eligible responders participated in the initial cognitive assessment (response rate 5 95.6%)

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