{"title":"Annual change in eGFR in renal hypouricemia: a retrospective pilot study.","authors":"Shinobu Sugihara, Yasutaka Yamamoto, Kei Teramoto, Toshiro Hamada, Satoshi Miyazaki, Kazuhide Ogino, Masanari Kuwabara, Akira Ohtahara, Einosuke Mizuta, Kimiyoshi Ichida, Yusuke Endo, Hiroyuki Minato, Haruaki Ninomiya, Masahiko Kato, Kazuhiro Yamamoto, Ichiro Hisatome","doi":"10.1007/s10157-024-02558-8","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Extremely low uric acid (UA) levels or increased urinary UA (Uua) excretion might be risk factors for kidney disease in renal hypouricemia (RHU) patients, but their relationship with kidney dysfunction is unclear. This study investigated time-dependent changes in eGFR in RHU patients.</p><p><strong>Methods: </strong>This multicenter retrospective study assessed UA metabolism and changes in eGFR (median 5.5 years) in 13 RHU patients. We then compared eGFR change in 7 of 13 RHU patients whose eGFR could be measured for 4 years with those in normouricemic group (n = 31). In addition, 7 RHU patients were divided into two groups based on URAT1 gene mutations: homozygote and compound heterozygote mutations (Homo/Com group, n = 3), and wild-type and heterogeneous mutations (WT/Hetero group, n = 4).</p><p><strong>Results: </strong>In 13 RHU patients, the median and mean serum UA (SUA) were 0.8 (0.4-2.5) and 1.1 ± 0.7 mg/dL. The median and mean Uua were 44.3 (12.7-141.1) and 49.7 ± 36.2 mg/dL. The median and mean urinary urate clearance (Cua/Ccr) were 46.8 (11.3-73.6) and 43.3 ± 19.7%. Over 4 years, eGFR did not change in the RHU group but declined in the normouricemic group. Annual mean eGFR decline and change rate in the RHU group were the same as those in the normouricemic group (- 1.09 ± 1.11 vs. - 1.09 ± 1.92 mL/min/1.73 m<sup>2</sup>/year, p = 0.996) (- 1.74 ± 1.96 vs. - 1.36 ± 2.10%, p = 0.664). And no significant difference was found in eGFR decline or change rate between Homo/Com and WT/Hetero groups (- 0.33 ± 1.03 vs. - 1.67 ± 0.85 mL/min/1.73 m<sup>2</sup>/year, p = 0.116) (- 0.61 ± 1.62 vs. - 2.59 ± 1.91%, p = 0.210).</p><p><strong>Conclusion: </strong>RHU from URAT1 genetic mutation may not show eGFR decline over 4 consecutive years.</p>","PeriodicalId":10349,"journal":{"name":"Clinical and Experimental Nephrology","volume":" ","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinical and Experimental Nephrology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s10157-024-02558-8","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"UROLOGY & NEPHROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Extremely low uric acid (UA) levels or increased urinary UA (Uua) excretion might be risk factors for kidney disease in renal hypouricemia (RHU) patients, but their relationship with kidney dysfunction is unclear. This study investigated time-dependent changes in eGFR in RHU patients.
Methods: This multicenter retrospective study assessed UA metabolism and changes in eGFR (median 5.5 years) in 13 RHU patients. We then compared eGFR change in 7 of 13 RHU patients whose eGFR could be measured for 4 years with those in normouricemic group (n = 31). In addition, 7 RHU patients were divided into two groups based on URAT1 gene mutations: homozygote and compound heterozygote mutations (Homo/Com group, n = 3), and wild-type and heterogeneous mutations (WT/Hetero group, n = 4).
Results: In 13 RHU patients, the median and mean serum UA (SUA) were 0.8 (0.4-2.5) and 1.1 ± 0.7 mg/dL. The median and mean Uua were 44.3 (12.7-141.1) and 49.7 ± 36.2 mg/dL. The median and mean urinary urate clearance (Cua/Ccr) were 46.8 (11.3-73.6) and 43.3 ± 19.7%. Over 4 years, eGFR did not change in the RHU group but declined in the normouricemic group. Annual mean eGFR decline and change rate in the RHU group were the same as those in the normouricemic group (- 1.09 ± 1.11 vs. - 1.09 ± 1.92 mL/min/1.73 m2/year, p = 0.996) (- 1.74 ± 1.96 vs. - 1.36 ± 2.10%, p = 0.664). And no significant difference was found in eGFR decline or change rate between Homo/Com and WT/Hetero groups (- 0.33 ± 1.03 vs. - 1.67 ± 0.85 mL/min/1.73 m2/year, p = 0.116) (- 0.61 ± 1.62 vs. - 2.59 ± 1.91%, p = 0.210).
Conclusion: RHU from URAT1 genetic mutation may not show eGFR decline over 4 consecutive years.
期刊介绍:
Clinical and Experimental Nephrology is a peer-reviewed monthly journal, officially published by the Japanese Society of Nephrology (JSN) to provide an international forum for the discussion of research and issues relating to the study of nephrology. Out of respect for the founders of the JSN, the title of this journal uses the term “nephrology,” a word created and brought into use with the establishment of the JSN (Japanese Journal of Nephrology, Vol. 2, No. 1, 1960). The journal publishes articles on all aspects of nephrology, including basic, experimental, and clinical research, so as to share the latest research findings and ideas not only with members of the JSN, but with all researchers who wish to contribute to a better understanding of recent advances in nephrology. The journal is unique in that it introduces to an international readership original reports from Japan and also the clinical standards discussed and agreed by JSN.