Bronchiectasis Exacerbation Increases the Risk of Adverse Renal Outcomes-Results From a Large Territory-Wide Cohort Study.

Introduction: Bronchiectasis exacerbation (BE) is associated with unfavorable sequelae in other organs such as the cardiovascular system; data regarding its impact on adverse term renal outcomes, however, is lacking.

Methods: A territory-wide retrospective cohort study was conducted in Hong Kong between 1/1/1993 and 31/12/2017. All patients with bronchiectasis followed in the public healthcare system in 2017 were classified as "Exacerbators" or "Non-Exacerbators," and their adverse renal outcomes (renal progression [decrease in eGFR by 30 mL/min lasted for more than 12 months during follow up], acute kidney injury [AKI], and annual rate of eGFR decline) in the ensuing 7 years were compared. Results were also analyzed in the 1:1 propensity score matched (PSM) cohort.

Results: A total of 7929 patients (1074 "Exacerbators" group and 6855 "Non-exacerbators") were followed for 6.2 ± 1.6 years. A total of 1570 patients (19.8%) had renal progression, and 935 (11.8%) patients developed AKI. "Exacerbators" showed significantly increased risk of renal progression (adjusted odds ratio [aOR] 1. 27 [95% CI 1.08-1.50, p = 0.003]), more rapid eGFR decline (-3.67 [-1.74 to -6.54] vs. -3.03 [-1.56 to -5.12] mL/min/1.73 m²/year, p = 0.004) and AKI (aOR 1.99; 95% CI 1.44-2.73, p < 0.001) than the "Non-exacerbators." Annual number of BE was associated with renal progression (aOR 1.45; 95% CI 1.22-1.72, p < 0.001) and AKI (aOR 2.00; 95% CI 1.38-2.91, p < 0.001). Results were consistent in the analysis with the PSM cohort.

Conclusions: Renal progression and AKI are common among patients with bronchiectasis, and BE is an independent risk factor for adverse renal outcomes.