Alcohol consumption and mortality in COPD: a population-based cohort study

COPD is characterised by multimorbidity and high mortality. Although alcohol consumption is associated with comorbidities common in COPD, its impact on COPD outcomes is uncertain. We investigated associations between baseline alcohol consumption and 10-year mortality, stratified by COPD status and examined whether comorbidity prevalence differed across alcohol categories.

COPD was defined by post-bronchodilator forced expiratory volume in 1 s/forced vital capacity <0.7; alcohol as ≤10 versus >10 units·week^-1. Comorbidities were ascertained from national registries. Cox models estimated mortality hazard ratios (HRs) adjusting for age, sex, smoking, education, body mass index and comorbidities. Inverse probability weighting addressed confounding. Logistic regression examined alcohol-comorbidity associations with false discovery rate correction.

In 2004-2006, 4528 Danish adults aged 45-84 years were recruited. Among 3468 participants with complete alcohol and COPD data (mean age 64 years; 65% male; 12% COPD), 593 deaths occurred over 10 years. Alcohol >10 units·week^-1 was not associated with mortality in unadjusted (HR 0.97 (95% CI 0.80-1.18)) or fully adjusted (HR 0.87 (95% CI 0.71-1.07)) models. COPD was strongly associated with mortality (adjusted HR 2.00 (95% CI 1.64-2.43)). No alcohol×COPD interaction was detected. Cardiovascular comorbidities were generally more prevalent among participants with COPD, although patterns varied. No associations between alcohol and individual comorbidities survived multiple testing correction.

In this cohort with predominantly moderate consumption, alcohol intake >10 units·week^-1 was not associated with 10-year mortality in adults with or without COPD, whereas COPD conferred excess risk independent of comorbidity and lifestyle factors. These findings should not be interpreted as evidence that alcohol consumption is safe.