Abstract
The World Trade Center (WTC) destruction released dust and fumes into the environment. Although many community members developed respiratory symptoms, screening spirometry was usually normal. We hypothesised that forced oscillation testing would identify functional abnormalities undetected by spirometry and that symptom severity would relate to magnitude of abnormalities measured by oscillometry.
A symptomatic cohort (n=848) from the Bellevue Hospital WTC Environmental Health Center was evaluated and compared to an asymptomatic cohort (n=475) from the New York City Department of Health WTC Health Registry. Spirometry and oscillometry were performed. Oscillometry measurements included resistance (R5) and frequency dependence of resistance (R5−20).
Spirometry was normal for the majority of subjects (73.2% symptomatic versus 87.6% asymptomatic, p<0.0001). In subjects with normal spirometry, R5 and R5−20 were higher in symptomatic versus asymptomatic subjects (median (interquartile range) R5 0.436 (0.206) versus 0.314 (0.129) kPa·L−1·s−1, p<0.001; R5−20 0.075 (0.085) versus 0.004 (0.042) kPa·L−1·s−1, p<0.0001). In symptomatic subjects, R5 and R5−20 increased with increasing severity and frequency of wheeze (p<0.05).
Measurement of R5–20 correlated with the presence and severity of symptoms even when spirometry was within normal limits. These findings are in accord with small airway abnormalities as a potential explanation of the respiratory symptoms.
Abstract
Small airway dysfunction in a symptomatic population with normal spirometry years after exposure to WTC dust http://ow.ly/TAxxf
Footnotes
Support statement: This study was supported by the American Red Cross Liberty Disaster Relief Fund, the City of New York, US Centers for Disease Prevention and Control (CDC) and National Institute for Occupational Safety and Health (NIOSH) grant 1E11OH009630, CDC-NIOSH Contracts 200-2011-39391, 200-2011-39397 and 200-2011-39413, and National Institute of Environmental Health Sciences grants ES00260 and T32ES07267. Funding information for this article has been deposited with FundRef.
Conflict of interest: None declared.
- Received July 7, 2015.
- Accepted October 12, 2015.
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