Abstract Rationale In contemporary cohorts of adults with cystic fibrosis (CF), risk factors and rates of kidney function decline are unknown. With improved life expectancy, preserving kidney function is paramount to preventing early cardiovascular disease, CF-related bone disease and to maintaining eligibility for lung transplantation. Objective To determine long-term kidney function decline among CF participants following the Standardized Treatment of Pulmonary Exacerbations 2 (STOP2) clinical trial, and identify specific risk factors. Methods We linked participants in STOP2 with the CF Foundation Patient Registry and defined decline in kidney function as a composite of ≥40% decline in the eGFR or development of end-stage renal disease (ESRD). We calculated the associations of risk factors, such as age, diabetes status, and number of pulmonary exacerbations treated with intraveneous antibiotics on decline in kidney function. Results Among 915 STOP2 participants, the mean (±SD) baseline eGFR was 114 (±20) mL/min/1.73m2 and 53 (6.0%) reached the composite endpoint over a median follow-up time of 3.8 years. Each 10-year increase in age was associated with a 24% greater risk of the composite outcome (HR 1.29; 95% CI: 1.01 to 1.65), and participants with insulin dependent diabetes had a greater risk of the composite endpoint (HR 2.34; 95% CI: 1.33 to 4.12). A multivariable adjusted time-updated Cox regression model demonstrated that each additional PEx was associated with a greater risk of the composite outcome (HR 1.13 (95% CI 1.07, 1.20) P 0.0001). Conclusions Risk factors associated with kidney function decline included age, insulin dependent diabetes, and number of pulmonary exacerbations. These findings highlight key contributors to kidney function decline in a modern cohort of adults with CF.
Nacharaju et al. (Tue,) studied this question.