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