Introduction: Elevated uric acid has been linked to the development of hypertension and also progression of kidney disease. Whether this is true in kidney transplant recipients, among whom hyperuricemia is common, has not been studied prospectively.
Methods: 153 kidney transplant recipients were randomized to Losartan (n=77) and placebo (n=76). Serum uric acid was measured at baseline and annually up to five years. Allograft biopsies and iothalamate GFR measurements were performed at baseline and annually. A linear regression model was used to estimate the effect of baseline uric acid on several outcomes at baseline, as well as measured GFR at five years. A mixed linear effects model was fit using backwards selection to assess predictors of uric acid.
Results: At baseline, mean uric acid was 5.57 ± 1.48 mg/dL; 102 (68.5%) recipients had uric acid <6 mg/dL, 23 (15.4%) between 6-7 mg/dL and 24 (16.1%) >7 mg/dL. Use of Losartan, female gender, thiazide diuretic use, deceased donor, lower BMI and higher iothalamate GFR were all associated with a significantly lower uric acid level at baseline and over time.
Conversely, baseline uric acid was not associated with baseline albuminuria, expansion of the interstitial compartment, or change in iothalamate GFR at 5 years.
|OUTCOME||ESTIMATE (95% CI), p-value|
|Doubling of interstitium or ESRD from IF/TA||0.49 (-0.21, 1.19), 0.17|
|Doubling of interstitium or any ESRD||0.24 (-0.41, 0.90), 0.46|
|Doubling of serum creatinine, all cause ESRD or Death||-0.23 (-0.77, 0.31), 0.41|
|Iothalamate GFR at 5 years||0.004 (-0.01, 0.02), 0.62|
|Interstitial volume at baseline||-3.18 (-9.17, 2.80), 0.29|
|Baseline urine albumin/creatinine ratio||-0.001 (-0.002, 0.001), 0.38|
Conclusion: In this cohort of kidney transplant recipients, higher uric acid was not associated with inferior kidney function or structure at 5 years, and Losartan was effective in reducing serum uric acid concentration. Whether treatment of asymptomatic hyperuricemia has clinical benefit remains uncertain.
To cite this abstract in AMA style:Hart A, Jackson S, Matas A, Ibrahim H. Predictors of Serum Uric Acid and Its Impact on Kidney Structure and Function: A Five Year Prospective Study [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/predictors-of-serum-uric-acid-and-its-impact-on-kidney-structure-and-function-a-five-year-prospective-study/. Accessed October 27, 2020.
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