D30-01 Acute Respiratory Events in Symptomatic Smokers Are Associated With Accelerated Lung Function Decline in the British Early COPD Network (Beacon) Cohort

Rationale Acute exacerbations of chronic obstructive pulmonary disease (COPD) are associated with disease progression, but their role in the disease development of young adult smokers is unknown. Higher baseline symptom burden (COPD Assessment Test (CAT) ≥ 10) is a risk factor for increased healthcare utilisation due to acute respiratory events in smokers with preserved lung function. Thus, we quantitatively assessed the effect of acute respiratory events in symptomatic young smokers on lung function decline. Methods Participants in the British EArly COPD Network (BEACON) multi-centre cohort (current smokers, aged 30-45 yrs, >10 pack-yrs tobacco history, FEV1 >80% predicted) (NCT03480347) were enrolled 2018-2020 and followed up every six months including spirometry. Detailed history of upper (URTI) & lower (LRTI) respiratory tract infections was recorded. The rate of FEV1 decline was assessed using linear regression with random effects, adjusted for current smoking status, current CAT score, age and sex. Results 401 participants, median age 39 years, median 16 pack-years smoked and median CAT score of 10 (Interquartile range [IQR] 8-12) had at least 12 months follow up data (median follow up 4.9 years (IQR 3.1-5.7) years). The annualized FEV1 decline rate was -34.4ml/yr (95% CI -44.4 to -27.4; P < 0.001). Participants with CAT ≥ 10 experienced higher rates of URTI (1.27 vs 0.87/year, p < 0.001), LRTI (0.34 vs 0.22/year, p = 0.003), LRTI requiring antibiotics (0.13 vs 0.07/year, p = 0.028), and unscheduled primary care visits (0.13 vs 0.06 /year, p = 0.012) compared to those with CAT < 10. In both adjusted models acute respiratory events were associated with greater FEV1 decline in symptomatic participants: URTI events demonstrate an additional -8.3ml/yr (95% CI -16.1 to -0.4; P = 0.038) decline, whilst LRTI events led to -26.5ml/yr (95% CI -46.3 to -6.7; P = 0.009) (figure 1A & 1B). Conclusions Among young adult smokers with preserved spirometry, greater baseline symptom burden was associated with increased frequency of acute respiratory events. Both URTI and LRTI independently contributed to excess FEV1 decline, underscoring the potential role of infections in the development of COPD in this at risk group. These data suggest a significant and potentially treatable component to disease development.