Kidney Week

Abstract: FR-PO198

Urinary PTH1R: Novel Predictor of Mineral Metabolism Disorder and Renal Outcome of CKD

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

• Qiu, Dandan, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China

Dandan Qiu,

• Pan, Yu, National Clinical Research Center of Kidney Diseases, Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China

Yu Pan,

• Shi, Jingsong, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China

Jingsong Shi,

• Zhou, Minlin, National Clinical Research Center of Kidney Diseases Jinling Hospital, Nanjing, China

Minlin Zhou,

• Xu, Feng, Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China

Feng Xu,

• Liu, Zhihong, National Clinical Research Center of Kidney Diseases,, Nanjing, JIangSu, China

Zhihong Liu,

• Jiang, Song, National Clinical Research Center of Kidney Diseases Jinling Hospital, Nanjing, China

Song Jiang,

Background

There is short of early predictor of mineral metabolism disorder and renal outcome in patients with chronic kidney disease (CKD). This study aimed to explore the association of urinary parathyroid hormone 1 receptor (PTH1R) with mineral metabolism markers, and the predictive value for renal outcome in CKD.

Methods

29 healthy controls and 140 diabetic nephropathy (DN) patientswere enrolled as discovery cohort and 200 general CKD patients were enrolled as an independent validation cohort. All patients were followed up for at least 1 year and measured the intact PTH (iPTH), fibroblast growth factor 23 (FGF23) in baseline serum and PTH1R in baseline urine.Urinary PTH1R was normalized to urine creatinine and log transformed [uPTH1R/Cr(log₁₀)].The composite renal endpoint was defined as end-stage renal disease (ESRD) or 30% reduction of baseline eGFR during follow-up.

Results

In discovery cohort, DN patients had a significantly higher mean uPTH1R/Cr(log₁₀) level compared with healthy control (2.53±0.61 pg/mg versus 1.89±1.14 pg/mg, P<0.01). uPTH1R/Cr(log₁₀) was significantly increased in DN patients with eGFR of 60~75 ml/min/1.73m², which was earlier than serum FGF23 and iPTH. Baseline uPTH1R/Cr(log₁₀) was associated with serum calcium (r=-0.224, P<0.01), serum FGF23 (r=0.232, P<0.05), and eGFR slope (r=0.318, P<0.001). 59 patients in discovery cohort entered into composite renal endpoint during follow-up. Cox regression analysis showed that higher uPTH1R/Cr(log₁₀) had a significantly higher risk for renal outcome [HR=2.190; 95%CI(1.048,4.575), P<0.05]. Validation cohort confirmed that uPTH1R/Cr(log₁₀) was an independent risk factor for renal outcome [HR=1.573; 95%CI(1.094,2.263), P<0.05] in general CKD patients. Addition of uPTH1R/Cr(log₁₀) to eGFR and proteinuria could significantly improve the prediction value for renal outcome (likelihood ratio test, P<0.001).

Conclusion

Urinary PTH1R was an independent risk factor for renal outcome in CKD patients, and was a novel biomarker of disordered mineral metabolism.