Indexed on: 29 Sep '18Published on: 29 Sep '18Published in: American journal of respiratory and critical care medicine
Chronic lower respiratory diseases (CLRD), including COPD and asthma, are the fourth leading cause-of-death. Prior studies suggest that albuminuria, a biomarker of endothelial injury, is increased in COPD patients. To test if albuminuria was associated with lung function decline and incident CLRD. Six US population-based cohorts were harmonized and pooled. Participants with prevalent clinical lung disease were excluded. Albuminuria (urine albumin-to-creatinine ratio) was measured in spot samples. Lung function was assessed by spirometry. Incident CLRD-related hospitalizations and deaths were classified via adjudication and/or administrative criteria. Mixed and proportional-hazards models were used to test individual-level associations adjusted for age, height, weight, sex, race/ethnicity, education, birth-year, cohort, smoking status, pack-years, renal function, hypertension, diabetes, and medications. Among 10,961 participants with preserved lung function, mean age at albuminuria measurement was 60 years, 51% were never-smokers, median albuminuria was 5.6mg/g, and mean FEV1 decline was 31.5mL/year. For each standard deviation increase in ln-albuminuria, there was 2.81% greater FEV1 decline (95% confidence interval [CI], 0.86-4.76%; P=0.0047), 11.02% greater FEV1/FVC decline (95% CI, 4.43-17.62%; P=0.0011), and 15% increased hazard of incident spirometry-defined moderate-to-severe COPD (95% CI, 2-31%, P=0.0021). Each standard deviation ln-albuminuria increased hazards of incident COPD-related hospitalization/mortality by 26% (95% CI, 18-34%, P<0.0001) among 14,213 participants followed for events. Asthma events were not significantly associated. Associations persisted in participants without current smoking, diabetes, hypertension, or cardiovascular disease. Albuminuria was associated with greater lung function decline, incident spirometry-defined COPD, and incident COPD-related events in a US population-based sample.