Abstract Rationale We have previously reported subclinical airway dysfunction using impulse oscillometry (IOS) among community members (Survivors) exposed to the World Trade Center (WTC) dust and fumes with normal spirometry. However, the predictive value of oscillometry for spirometry abnormalities has not been established in this environmentally exposed population. We investigated whether baseline oscillometry metrics predict future abnormal spirometry among WTC Survivors with normal spirometry at enrollment. Methods The binary normal pre-bronchodilator (BD) spirometry was defined as FEV1/FVC ≥ 0.70 and FEV1 ≥ 80%-predicted using Global Lung Function Initiative (GLI)-Global reference equation. We analyzed 482 participants from the WTC Environmental Health Center (EHC) cohort with normal spirometry at enrollment and who had 5 +/- 1 year follow-up data. Predictors included baseline pre-BD IOS measurements: airway resistance at 5Hz (R5), frequency dependence of resistance (R5-R20), and reactance area (AX). Logistic regression models were applied to assess whether baseline IOS metrics predicted abnormal spirometry at follow-up (binary outcome: normal vs. abnormal), adjusting for baseline demographics and WTC exposure characteristics, with or without further adjustment for baseline spirometry (FEV1 and FVC). Results When all IOS metrics were simultaneously modeled without baseline spirometry, AX demonstrated the strongest and statistically significant association with 5-year abnormal spirometry (OR = 2.2 per IQR change in log-AX, p = 0.008), while the effects of R5 and R5-R20 were not significant. After additional adjustment for baseline spirometry, AX remained significant (p = 0.041) and independently increased the odds of having abnormal spirometry by 73% per IQR change in log-AX. Conclusions Among WTC Survivors with initially normal spirometry, elevated baseline oscillometry metrics, particularly AX, predicted the subsequent development of spirometry abnormalities over five years. These findings highlight the potential of oscillometry as an early marker of subclinical airway dysfunction and support its application for longitudinal monitoring in environmentally exposed populations. This abstract is funded by: CDC/NIOSH Contract U01OH012637, CDC/NIOSH Contract 200 – 2017 – 93327, CDC/NIOSH Contract 200 – 2017 – 93427
Seok et al. (Fri,) studied this question.