Introduction
Respiratory symptoms predict accelerated lung function decline, COPD development & radiological changes among smokers without COPD.1,2 We hypothesised CAT scores would be higher among young adult smokers with accelerated decline in FEV1.
Methods
The Early COPD cohort (NCT03480347) is a multicentre, prospective study of smokers aged 30-45 years with >10 pack years history & FEV1?80% predicted. FEV1 decline (ml/yr) was estimated using random effects linear regression. The relationship between baseline CAT score & accelerated (>60ml/yr) vs. non-accelerated (<60ml/yr) FEV1 decline was tested using the Mann-Whitney U test.
Results
368 participants (59% male, median age 38 years). Median follow-up time: 32 months (Interquartile range: 24.2 to 41.5). Mean FEV1 decline rate was -35.8ml/yr (95%CI:-45.2 to -27.1;P<0.001). The 103 (28%) participants with accelerated FEV1 decline had higher baseline CAT scores than those without: 12.1 (IQR 8-16) vs.10.4 (IQR 6-14);P=0.026). Mucus production (P<0.001) & activity limitation (P<0.01) was greater among those with accelerated FEV1 decline (Fig 1).
Discussion
Total CAT score was greater in those with accelerated lung function decline, relative to those without, driven by differences in mucus production & activity limitation.
References
1. Allinson J et al. AJRCCM. 2016;193(6):662-72
2. Woodruff P et al. NEJM. 2016;374(19):1811-21