Obstructive sleep apnea and World Trade Center exposure

Is exposure to chemical pollutants associated with sleep outcomes? A systematic review

Environmental exposures may influence sleep; however, the contributions of environmental chemical pollutants to sleep health have not been systematically investigated. We conducted a systematic review to identify, evaluate, summarize, and synthesize the existing evidence between chemical pollutants (air pollution, exposures related to the Gulf War and other conflicts, endocrine disruptors, metals, pesticides, solvents) and dimensions of sleep health (architecture, duration, quality, timing) and disorders (sleeping pill use, insomnia, sleep-disordered breathing)). Of the 204 included studies, results were mixed; however, the synthesized evidence suggested associations between particulate matter, exposures related to the Gulf War, dioxin and dioxin-like compounds, and pesticide exposure with worse sleep quality; exposures related to the Gulf War, aluminum, and mercury with insomnia and impaired sleep maintenance; and associations between tobacco smoke exposure with insomnia and sleep-disordered breathing, particularly in pediatric populations. Possible mechanisms relate to cholinergic signaling, neurotransmission, and inflammation. Chemical pollutants are likely key determinants of sleep health and disorders. Future studies should aim to evaluate environmental exposures on sleep across the lifespan, with a particular focus on developmental windows and biological mechanisms, as well as in historically marginalized or excluded populations.

Prevalence of sleep disorders among first responders for medical emergencies: A meta-analysis

Background

Shift work and irregular work schedules among first responders have been associated with physical and psychological problems such as sleep disorders. We conducted the first meta-analysis to explore and estimate the prevalence of sleep disorders among first responders for medical emergencies.

Methods

We searched four databases: Web of Science, Psych Info, CINAHL, and PubMed. The Generalized Linear Mixed model (GLMM) was used to estimate the prevalence estimates of sleep disorders in R software and the DerSimonian-Lard random-effects model in Comprehensive Meta-Analysis was used to explore associated comorbidities for OSA and insomnia, presented as odds ratios (ORs) and confidence intervals (CIs). The Cochran's Q, τ², and the statistics were used to assess heterogeneity and the moderator analysis was conducted to identify moderator variables.

Results

Twenty-eight studies with 100 080 first responders were included from the total of 1119 studies retrieved from the databases. The prevalence rates for sleep disorders were 31% (95% CI = 15%-53%) for shift work disorder (SWD), 30% (95% CI = 18%-46%) for obstructive sleep apnea (OSA), 28% (95% CI = 19%-39%) for insomnia, 28% (95% CI = 24%-33%) for excessive daytime sleepiness (EDS), 2% (95% CI = 1%-4%) for restless leg syndrome, and 1% (95% CI = 0%-5%) for narcolepsy. Anxiety (OR = 2.46; 95% CI = 1.99%-3.03%), cardiovascular disease (CVD) (OR = 2.03; 95% CI = 1.43-2.88), diabetes mellitus (DM) (OR = 1.93; 95% CI = 1.41-2.65), depression (OR = 1.89; 95% CI = 1.01-3.56), gastroesophageal reflux disease (GERD) (OR = 1.83; 95% CI = 150-2.22), and post-traumatic stress disorder (PTSD) (OR = 1.78; 95% CI = 1.33-2.39) were associated with OSA. Depression (OR = 9.74; 95% CI = 4.67-20.3), anxiety (OR = 9.22; 95% CI = 3.81-22.3), and PTSD (OR = 7.13; 95% CI = 6.27-8.10) were associated with insomnia. Age, gender, first responders, continent, study quality, study design, and assessment tool were significant moderator variables for OSA, insomnia, and EDS.

Conclusions

This meta-analysis found a substantially high prevalence of sleep disorders including SWD, OSA, insomnia, and EDS among first responders for medical emergencies. Early assessment and management of sleep disorders among first responders is necessary to promote good, quality sleep to help prevent anxiety, depression, CVD, DM, GERD, and PTSD.

Risk Factors for COVID-19 in a Retired FDNY WTC-Exposed Cohort

We evaluated the incidence and risk factors for COVID-19 in a prospectively followed cohort of Fire Department of the City of New York (FDNY) World Trade Center (WTC)-exposed workers, thus reducing the potential for selection bias, a limitation in published studies of hospitalized individuals. Participants were retired FDNY WTC-exposed rescue/recovery workers with ≥1 medical visit between 1 March 2020 and 1 August 2021. The cumulative incidence was calculated using self-reported COVID-19 diagnoses. Cox regression was performed to evaluate the association of WTC-exposure and COVID-19, adjusting for history of comorbidities, age, race, work assignment (emergency medical service providers vs. firefighter), and sex. The cumulative incidence of COVID-19 was 130 per 1000. The adjusted models showed the risk of infection was greater in those with highest WTC exposure versus less exposure (hazard ratio (HR) = 1.14 (95% CI 1.00–1.31)). Older age was associated with a lower risk of infection HR = 0.97 (95% CI 0.96–0.98). WTC-associated diseases (obstructive airways disease and interstitial lung disease) were not COVID-19 risk factors. This study is the first to show an association between WTC exposure and the risk of COVID-19. While participants are retired from FDNY work, the youngest individuals may still be in the workforce, explaining why younger age was a significant risk for COVID-19.

Obstructive sleep apnoea and left ventricular diastolic dysfunction among first responders to the 9/11 World Trade Center terrorist attack: a cross-sectional study

OBJECTIVES

Obstructive sleep apnoea (OSA) is often linked to cardiovascular disease. A limited number of studies have reported an association between OSA and left ventricular diastolic dysfunction (LVDD). However, prior studies were performed on small patient populations. Studies have shown a high prevalence of OSA among first responders to the 9/11 World Trade Center (WTC) terrorist attack. We investigated the relationship between OSA and LVDD in a large population of WTC responders.

DESIGN

Cross-sectional study.

SETTING

One-time screening programme as part of the WTC-CHEST Study (NCT10466218), performed at a quaternary medical centre in New York City, from November 2011 to June 2014.

PARTICIPANTS

A total of 1007 participants with mean age of 51 years of mostly non-Hispanic white men were evaluated. Patients from the WTC Health Program-Clinical Center of Excellence, who were over the age of 39 years, were eligible to participate.

RESULTS

Evaluation of those without OSA diagnosis showed no significant association with LVDD when comparing those screened (Berlin Questionnaire) as OSA high risk versus OSA low risk (p=0.101). Among those diagnosed with LVDD, there was a significant association when comparing those with and without patient-reported OSA (OR 1.50, 95% CI 1.13 to 2.00, p=0.005), but the significance was not maintained after adjusting for pertinent variables (OR 1.3, 0.94 to 1.75, p=0.119). Notably, comparing those with OSA diagnosis and those low risk of OSA, the OR for LVDD was significant (1.69, 1.24 to 2.31, p=0.001), and after adjusting for waist-hip ratio, diabetes and coronary artery calcium score percentile, the relationship remained significant (OR 1.45, 1.03 to 2.04, p=0.032).

CONCLUSION

The strong association of OSA with LVDD in this population may inform future guidelines to recommend screening for LVDD in high-risk asymptomatic patients with OSA.

Twenty-Year Reflection on the Impact of World Trade Center Exposure on Pulmonary Outcomes in Fire Department of the City of New York (FDNY) Rescue and Recovery Workers

After the terrorist attacks on September 11, 2001 (9/11), many rescue/recovery workers developed respiratory symptoms and pulmonary diseases due to their extensive World Trade Center (WTC) dust cloud exposure. Nearly all Fire Department of the City of New York (FDNY) workers were present within 48 h of 9/11 and for the next several months. Since the FDNY had a well-established occupational health service for its firefighters and Emergency Medical Services workers prior to 9/11, the FDNY was able to immediately start a rigorous monitoring and treatment program for its WTC-exposed workers. As a result, respiratory symptoms and diseases were identified soon after 9/11. This focused review summarizes the WTC-related respiratory diseases that developed in the FDNY cohort after 9/11, including WTC cough syndrome, obstructive airways disease, accelerated lung function decline, airway hyperreactivity, sarcoidosis, and obstructive sleep apnea. Additionally, an extensive array of biomarkers has been identified as associated with WTC-related respiratory disease. Future research efforts will not only focus on further phenotyping/treating WTC-related respiratory disease but also on additional diseases associated with WTC exposure, especially those that take decades to develop, such as cardiovascular disease, cancer, and interstitial lung disease.

Sex and Gender in Research on Healthcare Workers in Conflict Settings: A Scoping Review

The occupational health literature has established that sex and gender are associated with all dimensions of the workplace. Sex and/or gender (sex/gender) factors play an important role in shaping the experiences, exposures, and health outcomes of male and female healthcare providers working in war and conflict settings. This study aims to (1) assess how sex/gender is considered in the occupational health literature on healthcare workers in conflict settings, and (2) identify the gaps in incorporating sex/gender concepts in this literature. A scoping review was carried out and nine electronic databases were searched using a comprehensive search strategy. Two reviewers screened the titles/abstracts and full-texts of the studies using specific inclusion and exclusion criteria. Key information was extracted from the studies and four themes were identified. Of 7679 identified records, 47 were included for final review. The findings underlined the harsh working conditions of healthcare workers practicing in conflict zones and showed sex/gender similarities and differences in experiences, exposures and health outcomes. This review revealed a dearth of articles with adequate consideration of sex/gender in the study design. Sex/gender-sensitive research in occupational health is necessary to develop effective occupational health and safety policies to protect men and women healthcare workers in conflict settings.

Burn pit exposure in military personnel: is there an effect on sleep-disordered breathing?

PURPOSE

Exposure to elevated concentrations of respirable particulate matter (< 10 μm) may influence sleep-disordered breathing. Burn pits as utilized by the US military in the Middle East until 2011 produced elevated particle matter concentrations. We seek to determine if subjective exposure to burn pits during deployment affects prevalence or severity of obstructive sleep apnea (OSA) in military personnel.

METHODS

As part of a prospective observational study of previously deployed military personnel with exertional dyspnea (n = 145), all patients underwent pulmonary function testing, screening for burn pit exposure, and if warranted by questionnaires, overnight polysomnography. A total of 100 patients completed all testing. For analysis, patients were classified into a burn pit exposure group (45 patients) and a no exposure group (55 patients). Additional analyses were performed on those endorsing burn pit maintenance during deployment (25 patients) and those with > 12 h of daily exposure (17 patients).

RESULTS

The prevalence of OSA, defined by apnea-hypopnea index (AHI) > 5/h, was similarly high in both groups (69% vs. 71%, p = 0.83). Surprisingly, the mean AHI was lower in the exposed group (12.8/h vs. 19.7/h, p = 0.04) while nadir of oxygen saturation was similar (87% vs. 86%, p = 0.39). Subgroup analyses revealed similar findings in those who performed burn pit maintenance (prevalence = 80%, p = 0.58; AHI = 14.8, p = 0.16) and those with > 12 h of daily exposure (prevalence = 88%, p = 0.33; AHI = 18.0, p = 0.62).

CONCLUSIONS

Subjective burn pit exposure does not appear to influence OSA development in previously deployed military personnel. Given the high rate of OSA in this cohort, continued investigation of deployment exposures which may influence sleep-disordered breathing is recommended.

Chronic Rhinosinusitis Is an Independent Risk Factor for OSA in World Trade Center Responders

BACKGROUND

Many respiratory conditions have been attributed to toxic dust and fume exposure in World Trade Center (WTC) rescue and recovery workers, who frequently report symptoms of OSA. We examined the prevalence of new-onset OSA and tested if the prevalence and severity of OSA are related to the presence of chronic rhinosinusitis (CRS).

METHODS

A total of 601 subjects (83% men; age, 33-87 years; BMI, 29.9 ± 5.5 kg/m²) enrolled in the WTC Health Program, excluding those with significant pre-September 11, 2001, snoring or prior CRS, underwent two nights of home sleep testing. OSA was defined as Apnea Hypopnea Index 4% ≥ 5 events/h or respiratory disturbance index of ≥ 15 events/h. CRS was assessed using nasal symptom questionnaires.

RESULTS

The prevalence of OSA was 75% (25% no OSA, 46% mild OSA, 19% moderate OSA, and 10% severe OSA), and the prevalence of CRS was 43.5%. Compared with no CRS, new and worsening CRS was a significant risk factor for OSA with an OR of 1.80 (95% CI, 1.18-2.73; P = .006) unadjusted and 1.76 (95% CI, 1.08-2.88; P = .02) after adjustment for age, BMI, sex, gastroesophageal reflux disorder, and alcohol use.

CONCLUSIONS

The high prevalence of OSA in WTC responders was not explained fully by obesity and sex. Possible mechanisms for the elevated risk of OSA in subjects with CRS include increased upper airway inflammation and/or elevated nasal/upper airway resistance, but these need confirmation.

Obstructive Sleep Apnea in Community Members Exposed to World Trade Center Dust and Fumes

STUDY OBJECTIVES

A relationship between obstructive sleep apnea (OSA) and exposure to the World Trade Center (WTC) dust and fumes has been suggested in responders but little is known about a possible relationship in community members. We characterized sleep studies performed in community members with WTC dust exposure to improve our understanding of the relationship between the diagnosis and severity of OSA and WTC dust exposure in this population.

METHODS

Single-center, retrospective study of patients enrolled in a clinical treatment program for community members with WTC dust exposure. Patients were included if they had undergone sleep studies for evaluation of possible OSA through September 2016 and provided written informed consent.

RESULTS

The total number of patients included in the analysis was 143. Patients were predominantly male (61%), never smokers (59%) and had a median body mass index of 31 kg/m². Most reported upper and lower respiratory symptoms. An apnea-hypopnea index (AHI) ≥ 5 events/h was measured in 66% of the patients, and respiratory disturbance index was ≥ 5 events/h in 97%. The proportion of patients with moderate-severe OSA (defined by the AHI 4% criteria) was 50%. Multivariate logistic regression revealed that acute WTC dust cloud exposure was associated with severity but not diagnosis of OSA.

CONCLUSIONS

We identified a high rate of OSA in the WTC community cohort who were referred for sleep studies. Exposure to the massive WTC dust cloud caused by the WTC collapse was independently associated with the severity of OSA in this population. This finding highlights the role that environmental exposures may play in the development of OSA.

Effects of Bedroom Environmental Conditions on the Severity of Obstructive Sleep Apnea

STUDY OBJECTIVES

Epidemiological associations have demonstrated the effects of long-term air pollution to obstructive sleep apnea (OSA) through a physiological mechanism linking particulate matter exposure to OSA. This study aimed to determine the relationship between bedroom environmental conditions, OSA severity, and sleep quality.

METHODS

Sixty-three participants were enrolled for an overnight polysomnography; OSA was diagnosed between May to August 2016. Personal characteristics and sleep quality were obtained by a face-to-face interview. Bedroom environments, including data on particulate matter with an aerodynamic diameter less than 10 μm (PM₁₀), temperature, and relative humidity, were collected by personal air sampling and a HOBO tempt/RH data logger.

RESULTS

Sixty-eight percent of the participants experienced poor sleep. An elevation in 1-year mean PM₁₀ concentration was significantly associated with an increase in apnea-hypopnea index (beta = 1.04, P = .021) and respiratory disturbance index (beta = 1.07, P = .013). An increase of bedroom temperature during sleep was significantly associated with poorer sleep quality (adjusted odds ratio 1.46, 95% confidence interval 1.01-2.10, P = .044). Associations between PM₁₀ concentration and respiratory disturbance index were observed in the dry season (beta = 0.59, P = .040) but not in the wet season (beta = 0.39, P = .215). PM₁₀ was not associated with subjective sleep quality.

CONCLUSIONS

Elevation of PM₁₀ concentration is significantly associated with increased OSA severity. Our findings suggest that reduction in exposure to particulate matter and suitable bedroom environments may lessen the severity of OSA and promote good sleep.

Occupation and Obstructive Sleep Apnea: A Meta-Analysis

OBJECTIVE

Obstructive sleep apnea (OSA) remains a prevalent condition, but its occupational burden is unclear. We carried out a systematic review to characterize the consistency and magnitude of occupational associations with OSA.

METHODS

We studied OSA within three occupational categories: commercial drivers, organic solvent-exposed workers, other selected occupations. We performed a meta-analysis on the prevalence of OSA among drivers and the risk of OSA associated with solvent exposure.

RESULTS

The pooled OSA prevalence in drivers was 41% (95% confidence interval [CI] 26% to 56%) for apnea hypopnea-index (AHI) is greater than 5, and 15% (95% CI 12% to 19%) for AHI is greater than 15. Exposure to solvents was associated with increased but non-statistically significant risk of OSA: summary relative risk, 2.38 (95% CI 0.89 to 6.32). Evidence of occupational association was inconsistent for other factors.

CONCLUSIONS

OSA is common among commercial drivers and potentially associated with occupations involving likely solvent exposure.

Review of Non-Respiratory, Non-Cancer Physical Health Conditions from Exposure to the World Trade Center Disaster

After the World Trade Center attacks on 11 September 2001 (9/11), multiple cohorts were developed to monitor the health outcomes of exposure. Respiratory and cancer effects have been covered at length. This current study sought to review the literature on other physical conditions associated with 9/11-exposure. Researchers searched seven databases for literature published in English from 2002 to October 2017, coded, and included articles for health condition outcome, population, 9/11-exposures, and comorbidity. Of the 322 titles and abstracts screened, 30 studies met inclusion criteria, and of these, 28 were from three cohorts: the World Trade Center Health Registry, Fire Department of New York, and World Trade Center Health Consortium. Most studies focused on rescue and recovery workers. While many of the findings were consistent across different populations and supported by objective measures, some of the less studied conditions need additional research to substantiate current findings. In the 16 years after 9/11, longitudinal cohorts have been essential in investigating the health consequences of 9/11-exposure. Longitudinal studies will be vital in furthering our understanding of these emerging conditions, as well as treatment effectiveness.

Sleep apnea and pesticide exposure in a study of US farmers

INTRODUCTION

Carbamate and organophosphate pesticides inhibit acetylcholinesterase, and poisoning leads to respiratory depression. Thus, involvement in sleep apnea is plausible, but no data exist at lower levels of exposure. Other pesticides could impact sleep apnea by different mechanisms but have not been studied. Our study examines the associations between pesticide exposure and sleep apnea among pesticide applicators from a US farming population.

PARTICIPANTS AND METHODS

We analyzed data from 1569 male pesticide applicators, mostly farmers, from an asthma case-control study nested within the prospective Agricultural Health Study. On questionnaires, participants reported use of specific pesticides and physician diagnosis plus prescribed treatments for sleep apnea. We used multivariable logistic regression to estimate associations between ever use of 63 pesticides and sleep apnea (234 cases, 1335 noncases).

RESULTS

The most notable association was for carbofuran, a carbamate (100 exposed cases, odds ratio 1.83, 95% confidence interval 1.34-2.51, P=.0002). Carbofuran use began before reported onset of sleep apnea in all cases.

DISCUSSION

This study adds to the known adverse health outcomes of exposure to carbofuran, a pesticide canceled in the United States in 2009 for most agricultural purposes but persists in the environment and remains in use in some other countries.

CONCLUSIONS

We conducted the first epidemiological study investigating the association of pesticide exposure and sleep apnea. Our results in a male agricultural population suggests that exposure to carbofuran is positively associated with sleep apnea.

An Official American Thoracic Society Workshop Report: Chemical Inhalational Disasters. Biology of Lung Injury, Development of Novel Therapeutics, and Medical Preparedness

This report is based on the proceedings from the Inhalational Lung Injury Workshop jointly sponsored by the American Thoracic Society (ATS) and the National Institutes of Health (NIH) Countermeasures Against Chemical Threats (CounterACT) program on May 21, 2013, in Philadelphia, Pennsylvania. The CounterACT program facilitates research leading to the development of new and improved medical countermeasures for chemical threat agents. The workshop was initiated by the Terrorism and Inhalational Disasters Section of the Environmental, Occupational, and Population Health Assembly of the ATS. Participants included both domestic and international experts in the field, as well as representatives from U.S. governmental funding agencies. The meeting objectives were to (1) provide a forum to review the evidence supporting current standard medical therapies, (2) present updates on our understanding of the epidemiology and underlying pathophysiology of inhalational lung injuries, (3) discuss innovative investigative approaches to further delineating mechanisms of lung injury and identifying new specific therapeutic targets, (4) present promising novel medical countermeasures, (5) facilitate collaborative research efforts, and (6) identify challenges and future directions in the ongoing development, manufacture, and distribution of effective and specific medical countermeasures. Specific inhalational toxins discussed included irritants/pulmonary toxicants (chlorine gas, bromine, and phosgene), vesicants (sulfur mustard), chemical asphyxiants (cyanide), particulates (World Trade Center dust), and respirable nerve agents.

FDNY and 9/11: Clinical services and health outcomes in World Trade Center-exposed firefighters and EMS workers from 2001 to 2016

BACKGROUND

After the World Trade Center (WTC) attacks on September 11, 2001, the Fire Department of the City of New York (FDNY) instituted a WTC medical monitoring and treatment program and established a data center to document health outcomes in the WTC-exposed workforce of ∼16,000 firefighters and EMS workers.

METHODS

FDNY schedules routine monitoring exams every 12-18 months and physical and mental health treatment appointments, as required.

RESULTS

FDNY research studies have consistently found that early arrival to work and/or prolonged work at the WTC-site increased the risks for adverse physical and mental health outcomes. To date, a substantial proportion has been diagnosed with obstructive airways disease, chronic rhinosinusitis, and gastroesophageal reflux disease; a quarter has two or more of these conditions.

CONCLUSIONS

While much has been learned, the entire spectrum and trajectory of WTC-related disorders and their mechanisms of onset and persistence remain to be fully described. Am. J. Ind. Med. 59:695-708, 2016. © 2016 Wiley Periodicals, Inc.