Effect of hemodialysis and transplantation on sodium stores in end-stage renal disease
Nephrology
Final Report Abstract
Decreased renal function as occurs in Chronic Kidney Disease (CKD) causes salt-sensitive hypertension. Whether CKD results in tissue Na+ accumulation and if kidney transplantation affects tissue Na+ has not been established. In a case-control study we compared tissue Na+ amount in 56 CKD patients (stage 4/5) to 56 age and gender-matched control subjects and then prospectively evaluated tissue Na+ content following living donor kidney transplantation. 23Na-Magnetic Resonance Imaging (23Na-MRI) was used to quantify muscle and skin Na+ of the lower leg. In the prospective cohort trial 31 patients from the initial CKD group underwent kidney transplantation and were re-assessed using 23Na-MRI and bioimpedance spectroscopy, 3 and 6 months after transplantation. Compared to control subjects, CKD-patients showed increased muscle (20.6±4.7 vs. 15.7±1.8 a.u., p<0.001) and skin Na+ content (21.9±8.3 vs. 15.2±3.2 a.u., p<0.001), whereas serum Na+ concentration did not differ between groups. Restoration of kidney function by successful renal transplantation was accompanied by reduced blood pressure, increased Vascular Endothelial Growth Factor-C (VEGF-C), and mobilization of tissue Na+ from muscle (20.7±5.0 vs. 16.8±2.8 a.u., p<0.001) and skin (21.4±7.7 vs. 16.8±5.2 a.u., p<0.001) 6 months post-transplantation. In conclusion, tissue Na+ accumulation occurs in pre-dialysis patients with CKD that could be almost completely reversed by successful kidney transplantation. Reduction of tissue Na+ after kidney transplantation was associated with normalization of blood pressure and lymphatic growth-factor plasma concentration. Based on this findings future long-term prospective studies have to assess the relevance of Na+ accumulation for cardiovascular disease after kidney transplantation and the role of allograft rejection with subsequent tissue Na+ retention. In future tissue Na+ could be developed as a prognostic marker in CKD and transplant patients.
Publications
- Na+ Deposition in the Fibrotic Skin of Systemic Sclerosis Patients detected by 23Na-Magnetic Resonance Imaging. Rheumatology 2017; 56(4):556-560
Kopp C, Beyer C, Linz P, Dahlmann A, Hammon M, Jantsch J, Neubert P, Amslinger D, Müller DN, Cavallaro A, Eckardt KU, Schett G, Luft FC, Uder M, Distler JH, Titze J
(See online at https://doi.org/10.1093/rheumatology/kew371) - Elevated tissue Na+ deposition in type 2 diabetic hemodialysis patients detected by 23Na-Magnetic Resonance Imaging. Kidney Int. 2018 May;93(5):1191-1197
Kopp C, Linz P, Maier C, Wabel P, Hammon M, Nagel AM, Rosenhauer D, Horn S, Uder M, Luft FC, Titze J and Dahlmann A
(See online at https://doi.org/10.1016/j.kint.2017.11.021)
