Is urinary oxalate inversely correlated with glomerular filtration rate in chronic kidney disease?
Is urinary oxalate inversely correlated with glomerular filtration rate in chronic kidney disease?
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慢性肾脏病患者尿草酸盐与肾小球滤过率呈负相关吗？
DOI：
10.1080/0886022x.2019.1614059
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发表时间：
2019-01
期刊：
影响因子：
3
通讯作者：
Yu Shengqiang
中科院分区：
文献类型：
--
作者：
Xue Cheng;Zhou Chenchen;Xu Jing;Zhang Liming;Yu Shengqiang
草酸盐是一种潜在的代谢毒素，主要通过肾小管分泌和肾小球滤过经肾脏排出。Waikar等人最近进行的一项临床试验（CRIC研究）发现，在2-4期慢性肾病（CKD）患者中，2 - 4小时尿草酸盐排泄量增加与估计肾小球滤过率（GFR）下降50%和终末期肾病（ESRD）风险增加相关[1]。该试验还显示，24小时尿草酸排泄与eGFR呈负相关（r1/4 0.13，p<0.001），这验证了尿草酸对CKD进展风险的预测作用[1]。然而，较低的GFR通常导致在早期CKD代偿性滤过负荷增加时尿草酸排泄不变或略有减少，并导致在晚期CKD肾小球失代偿期间尿草酸排泄减少。发现eGFR降低与肾结石患者尿草酸盐水平降低相关[2]。几乎没有证据可以解释Waikar等人的研究中尿草酸排泄和eGFR之间的负相关性。的研究。我们认为，体重指数（BMI）和糖尿病可能部分解释了这一结果。我们注意到，尿草酸排泄量在五分位数5的患者比低五分位数的患者有更高的BMI和更多的糖尿病患者，不同五分位数之间存在统计学差异（p< .001）[1]。较高的BMI和糖尿病均与较高的有效肾血浆流量和肾小球超滤相关，可导致尿草酸盐排泄增加[3，4]。此外，在非糖尿病患者和BMI <32.1的患者亚组中，草酸盐与ESRD之间的相关性变得不显著，并且尿草酸盐与CKD进展风险之间没有剂量反应相关性[1]。虽然在结果中对BMI和糖尿病进行了多变量调整，但由于总样本的BMI相对较高（32.1±7.7），CRIC研究参与者可能存在抽样偏倚[1]。此外，蛋白质摄入量对肾血浆流量和GFR也有积极影响，但CRIC研究中没有提供。最近土耳其的一项研究表明，草酸排泄与儿童蛋白质摄入量增加呈正相关，与年龄呈负相关，这表明蛋白质饮食摄入量的变化会影响尿草酸排泄[5]。因此，CKD患者24小时尿草酸排泄量与eGFR之间的关系较为复杂，需要更多的研究来证实。
Oxalate is a potentially metabolic toxin which is eliminated mainly through the kidney by tubular secretion and glomerular filtration. A recent clinical trial (CRIC study) conducted by Waikar et al. found that higher 24-h urinary oxalate excretion was associated with increased risk of 50% decline in estimated glomerular filtration rate (GFR) and end-stage renal disease (ESRD) in patients with chronic kidney disease (CKD) stages 2–4 [1]. The trial also showed that 24-h urinary oxalate excretion was inversely correlated with eGFR (r1⁄4 0.13, p< .001), which verified the predictive role of urinary oxalate on the risk of CKD progression [1]. However, lower GFR usually leads to unchanged or slightly decreased urinary oxalate excretion when compensatory filtered load increases in early CKD, and leads to decreased urinary oxalate excretion during glomeruli decompensation in advanced CKD. The reduction in eGFR was found to be associated with decreased urine oxalate levels in patients with nephrolithiasis [2]. Few evidence can explain the inverse correlation between urinary oxalate excretion and eGFR in Waikar et al.’s study. In our opinion, body mass index (BMI) and diabetes may partially explain this result. We noticed that patients with urinary oxalate excretion in quintile 5 had higher BMIs and with more diabetes than patients in lower quintiles, and there were statistical differences among different quintiles (p< .001) [1]. Higher BMI and diabetes, both associated with higher effective renal plasma flow and glomerular hyperfiltration, could lead to the increased excretion of urinary oxalate [3,4]. Moreover, the associations between oxalate and ESRD became insignificant in subgroups of patients without diabetes and patients with BMI of <32.1, and there was not a dose–response association between urinary oxalate and CKD progression risk [1]. Although multivariable adjustments for BMI and diabetes were performed in the results, there may be sampling bias in the participants of CRIC study, because the BMI of the total sample was relatively high (32.1±7.7) [1]. Besides, protein intake, which impacts renal plasma flow and GFR positively as well, is not available in CRIC study. A recent Turkish study demonstrated a positive correlation of oxalate excretion with increased protein intake and a negative correlation with age in children, which indicated the variation of dietary intake of proteins can affect urinary oxalate excretion [5]. Therefore, the association between 24-h urinary oxalate excretion and eGFR in CKD is complicated and needs more studies to confirm.
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影响因子：
3
作者：
Dursun I;Çelik İ;Poyrazoglu HM;Köse K;Tanrıkulu E;Sahin H;Yılmaz K;Öztürk A;Yel S;Gündüz Z;Düşünsel R
通讯作者：
Düşünsel R
影响因子：
39
作者：
Waikar, Sushrut S.;Srivastava, Anand;Townsend, Raymond R.
通讯作者：
Townsend, Raymond R.
DOI：
10.2215/cjn.01410308
发表时间：
2008-09-01
影响因子：
9.8
作者：
Taylor, Eric N.;Curhan, Gary C.
通讯作者：
Curhan, Gary C.
影响因子：
2.1
作者：
Gershman, Boris;Sheth, Sonali;Eisner, Brian H.
通讯作者：
Eisner, Brian H.