Kidney Function, Kidney Function Decline, and the Risk of Abdominal Aortic Aneurysm: The Stockholm CREAtinine Measurements (SCREAM) Project.

Objective: Low estimated glomerular filtration rate (eGFR) increases the risk of arterial diseases, possibly including abdominal aortic aneurysm (AAA). This study explored the relationship between eGFR (2008 CKD-EPI equation), annual eGFR decline, and subsequent risk of developing AAA in a large, community based sample.

Methods: This was an observational study using complete healthcare records of Stockholm residents free from AAA who underwent routine creatinine testing during 2011 - 2021. Cox regression, adjusted for age, sex, comorbidities, and ongoing medications, was used to analyse the association between a single point eGFR or the change in eGFR within a year and the rate of both a de novo AAA diagnosis (both intact and ruptured) and fatal AAA (i.e., AAA followed by death within 30 days).

Results: The study included 1 586 410 participants (mean age 48 years; 53% female; median eGFR 96 mL/min/1.73 m²). During a median follow up of 7.6 years, 5 313 participants (0.34%) experienced AAA, of which 321 (0.02%) were fatal. In multivariable analyses, compared with eGFR 90 mL/min/1.73 m², the rates of AAA events were higher across lower eGFR: for eGFR 30 mL/min/1.73 m², the hazard ratio (HR) of AAA was 1.24 (95% confidence interval [CI] 1.09 - 1.40) and of fatal AAA was 2.51 (95% CI 1.67 - 3.75); for eGFR 15 mL/min/1.73 m², the HR of AAA was 1.49 (95% CI 1.19 - 1.86) and of fatal AAA was 3.73 (95% CI 2.04 - 6.81). When analysed separately, the results were similar for intact and ruptured AAA risk. Among the 638 959 participants who had repeated eGFR tests, 3 447 (0.54%) experienced AAA events, of which 217 (0.04%) were fatal. Compared with stable eGFR (change -1 to 1 mL/min/year), the rate of AAA events was 15% higher (HR 1.15, 95% CI 1.05 - 1.26) in participants with an eGFR decline of 1 to 3 mL/min/year and 46% higher (HR 1.46, 95% CI 1.16 - 1.84) in those with an eGFR decline of > 3 mL/min/year.

Conclusion: In this observational study, both a single point eGFR and a faster eGFR decline were associated with the risk of experiencing AAA. The incidence rate of AAA, and particularly fatal AAA, was higher in individuals with greater severity of chronic kidney disease or faster eGFR decline.