Kidney Week

Abstract: FR-PO179

The Impact of Hyperuricemia on Kidney Failure and Mortality in a Multi-center CKD Cohort: An Instrumental Variable Analysis

Session Information

• CKD: Epidemiology, Risk Factors, Prevention - II
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 1901 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Kim, Yong Chul, SNUH, Seoul, Korea (the Republic of)

Yong Chul Kim,

• An, Jung Nam, Seoul National University Boramae Medical Center, Seoul, SEOUL, Korea (the Republic of)

Jung Nam An,

• Kim, Dong Ki, Seoul National University Hospital, Seoul, Korea (the Republic of)

Dong Ki Kim,

• Lim, Chun Soo, Seoul National University Boramae Medical Center, Seoul, SEOUL, Korea (the Republic of)

Chun Soo Lim,

• Kim, Yon Su, Seoul National University College of Medicine, Seoul, Korea (the Republic of)

Yon Su Kim,

• Lee, Jung Pyo, Seoul National University Boramae Medical Center, Seoul, SEOUL, Korea (the Republic of)

Jung Pyo Lee,

Background

Hyperuricemia is an independent risk factor for mortality, cardiovascular disease, and renal disease in general population. However, the relationship between hyperuricemia with kidney failure and death in chronic kidney disease (CKD) remains controversial.

Methods

The study investigated the association between uric acid with all-cause mortality, end stage renal disease (ESRD) in 42,253 CKD patients in a multi-center cohort from 2001 to 2016. We used the regional prevalence of hyperuricemia (uric acid ≥ 6.8 mg/dL) as an instrument to test our hypothesis that hyperuricemia is associated with ESRD and mortality.

Results

In all subjects, the mean uric acid level was 5.4 ± 1.8 mg/dL. During a median year follow-up, there were 3,556 (8.42%) of renal failure and 5,094 (12.06%) of death in this cohort. Using an instrumental variable analysis after adjusting confounders such as age, diabetes, hypertension and estimated GFR (eGFR), we found evidence suggesting a causal relationship between hyperuricemia and increased risk of all-cause mortality (HR 3.131, 95% CI 2.043-4.797, P < 0.001). This tendency was consistent regardless of gender (male: HR 2.270, 95% CI 1.338-3.851, P = 0.002, female: HR 2.656, 95% CI 1.459-4.834, P = 0.001). On the contrary, higher uric acid concentrations were independently associated with reduced risk for kidney failure in the entire participants (HR 0.539, 95% CI 0.318-0.915, P = 0.022), especially in patients with reduced renal functions (eGFR below 30, HR 0.189, 95% CI 0.098-0.366, P < 0.001).

Conclusion

Instrumental variable analysis supports that uric acid concentration is an independent risk factor for all-cause mortality, while hyperuricemia might have protective effect for ESRD, especially in reduced renal function.