The impact of bronchiectasis and its severity on long-term renal outcomes

<bold>Introduction:</bold> Bronchiectasis is associated with adverse cardiovascular outcomes; but data regarding its impact on long-term renal outcomes is lacking. <bold>Methods:</bold> We reviewed all bronchiectasis patients who were followed at Queen Mary Hospital in 2017 and examined their clinical/renal outcomes in the subsequent five years. The relationships between severity of bronchiectasis (as defined by FACED scores) and adverse renal outcomes were evaluated. <bold>Results:</bold> 350 patients were included [162 (49.1%), 108 (34.3%) and 45 (14.3%) patients with mild, moderate, and severe bronchiectasis respectively. Seventy-five patients (23.8%) showed renal progression. Baseline FACED score showed a positive correlation with renal progression over 5 years of follow up [adjusted odds ratio (aOR) 1.277 (95%CI 1.041–1.566), p=0.019]. Patients with moderate-to-severe bronchiectasis (FACED score ≥3) showed an increased risk of renal progression [aOR of 1.891 (95%CI 1.059-3.377), p=0.031] and more rapid eGFR decline than those with mild disease (−4.77±4.19 mL/min/1.73m2/year vs. -3.49±3.94 mL/min/1.73m2/year, p=0.006). Patients who developed renal progression had higher risk of death [adjusted hazard ratio (aHR) 2.545 (95%CI 1.159-5.588), p=0.020] and subsequent rates of hospitalization (1.56 ± 2.81 episodes/year vs. 0.60 ± 1.18 episodes/year; p < 0.001) compared to those without renal progression. <bold>Conclusion:</bold> Progressive renal function deterioration is prevalent amongst bronchiectasis patients, and the severity of bronchiectasis is a robust predictor for renal progression. Bronchiectasis patients with renal progression showed increased risk of mortality and higher subsequent rates of hospitalization.