High Uric Acid And Kidney Disease
A new report studying high uric acid and kidney disease confirms earlier indications of the dangers of hyperuricemia revealed by the 2008 Austrian investigations.
In a study investigating the “Association between serum uric acid and early kidney damage in middle-aged and elderly”, Chinese scientists show a clear correlation between high uric acid in the blood and reduced kidney function.
Though this new report[1] adds nothing to the Austrian study[2] in terms of understanding why elevated uric acid leads to kidney impairment, it does confirm that the two are linked. It certainly adds weight to my position that asymptomatic hyperuricemia should be taken much more seriously.
High Uric Acid And Kidney Disease Investigation
The following information is extracted from the abstract of the uric acid investigation: “Association between serum uric acid and early kidney damage in middle-aged and elderly.”
Uric Acid Investigation Objectives
To investigate the association between uric acid in the blood and early kidney damage. Also investigate the prevalence of early kidney damage in the middle-aged and elders with normal serum creatinine.
Uric Acid Investigation Methods
The investigation surveyed 1023 subjects from the local population of Chengdu in China. The study group comprised of 539 men and 484 women aged between 57 and 69, selected randomly from the population with normal serum creatinine.
Subjects were divided into 4 groups determined by uric acid level in the blood:
- Less than 4.74 mg/dL (0.282 mmol/L)
- 4.74 mg/dL to 5.56 mg/dL (0.331 mmol/L)
- 5.56 mg/dL to 6.37 mg/dL (0.379 mmol/L)
- Greater than 6.37 mg/dL
Clearly not gout sufferers, but this is about uric acid, not necessarily gouty arthritis. The survey looked at cardiovascular risk factors, including serum UA and estimated glomerular filtration rate (eGFR) using the MDRD (modification of diet in renal disease) equation.
Uric Acid Investigation Results
Overall, 28.1% of subjects had early kidney damage, with men, at 35.8%, much more susceptible than women at 19.5%. The incidence of early kidney disease was analyzed to calculate the odds ratio across each of the 4 study groups. Taking the value of group A as 1, the other groups show the following risks:
- 1.0
- 1.740
- 3.599
- 5.488
Uric Acid Investigation Conclusion
The investigation concludes:
In the middle-aged and elders with normal serum creatinine, serum UA and eGFR are negatively correlated. And serum UA level is independently associated with early kidney damage.
GoutPal Conclusion
Given that the earlier study showed that uric acid levels above 9 mg/dL are associated with triple the incidence of kidney disease compared to below 7mg/dL, then any uric acid level above 5mg/dL suggests cause for concern.
Neither of these studies have shown whether high uric acid impairs kidney function or if kidney disease caused by something else causes uric acid levels to rise. Given that Siu and colleagues have shown allopurinol to be beneficial for kidney disease sufferers[3], I reckon there are good grounds to suggest that lowering the uric acid will lower the risk of kidney disease. As ever, this are cries out for more specific research. If you find some, please share it with the world on the gout forum.
High Uric Acid And Kidney Disease References
- He S, Chen XP, Jiang LY, Peng Y, Gong L, Chen XN, Wu K, Cui KJ, Zhu Y, Huang DJ. [Association between serum uric acid and early kidney damage in middle-aged and elderly]. Zhonghua Yi Xue Za Zhi. 2010 Mar 16;90(10):658-61. [Article in Chinese]
- Obermayr RP, Temml C, Gutjahr G, Knechtelsdorfer M, Oberbauer R, Klauser-Braun R. Elevated uric acid increases the risk for kidney disease. J Am Soc Nephrol. 2008 Dec;19(12):2407-13. Epub 2008 Sep 17.
- Siu YP, Leung KT, Tong MK, Kwan TH. Use of allopurinol in slowing the progression of renal disease through its ability to lower serum uric acid level. Am J Kidney Dis. 2006 Jan;47(1):51-9.
~GoutPal