Association between occupational dust exposure and prognosis of idiopathic pulmonary fibrosis: A Korean national survey
Previous studies have investigated the relationship between occupational and environmental agents and idiopathic pulmonary fibrosis (IPF). However, there have been few studies regarding the prognosis of IPF patients, according to patient occupation.
We investigated whether occupational dust exposure was associated with clinically decreased lung function and poor prognosis.
The Korean Interstitial Lung Disease Research Group conducted a national survey to evaluate the clinical, physiological, radiological, and survival characteristics of IPF patients. A total of 1,311 IPF patients were stratified into five groups, according to their occupation: (1) unemployed or homemakers (n = 628); (2) farmers, fishers, or ranchers (n = 230); (3) sales or service personnel (n = 131); (4) clerical or professional personnel (n = 151); (5) specific dust-exposed workers (n = 171).
The mean age of subjects, at diagnosis, was 67.5 ± 9.7 years. Current smokers were 336 patients, 435 were ex-smokers, and 456 were never smokers. Dust-exposed workers showed early onset of IPF (61.3 ± 8.6 years, p < 0.001) and a longer duration of symptoms at diagnosis (17.0 ± 28.2 months, p = 0.004). Aging (p = 0.001; hazard ratio [HR], 1.034; 95% confidence interval [CI], 1.014–1.054), forced vital capacity (% of predicted) at diagnosis (p = 0.004; HR, 0.984; 95% CI, 0.974–0.995), and dust-exposure occupation (p = 0.033; HR, 1.813; 95% CI, 1.049–3.133) were associated with mortality.
These findings indicate that occupational dust may be an aggravating factor associated with a poor prognosis in IPF.