Qirjazi Elena, Salerno Fabio R, Akbari Alireza, Hur Lisa, Penny Jarrin, Scholl Timothy, McIntyre Christopher W
Department of Medical Biophysics, Western University, London, Ontario, Canada.
Alberta Health Services, Calgary, Alberta, Canada.
Nephrol Dial Transplant. 2020 Apr 6. doi: 10.1093/ndt/gfaa036.
Sodium-23 magnetic resonance imaging (23Na MRI) allows direct measurement of tissue sodium concentrations. Current knowledge of skin, muscle and bone sodium concentrations in chronic kidney disease (CKD) and renal replacement therapy patients is limited. In this study we measured the tissue sodium concentrations in CKD, hemodialysis (HD) and peritoneal dialysis (PD) patients with 23Na MRI of the lower leg and explored their correlations with established clinical biomarkers.
Ten healthy controls, 12 CKD Stages 3-5, 13 HD and 10 PD patients underwent proton and 23Na MRI of the leg. The skin, soleus and tibia were segmented manually and tissue sodium concentrations were measured. Plasma and serum samples were collected from each subject and analyzed for routine clinical biomarkers. Tissue sodium concentrations were compared between groups and correlations with blood-based biomarkers were explored.
Tissue sodium concentrations in the skin, soleus and tibia were higher in HD and PD patients compared with controls. Serum albumin showed a strong, negative correlation with soleus sodium concentrations in HD patients (r = -0.81, P < 0.01). Estimated glomerular filtration rate showed a negative correlation with tissue sodium concentrations (soleus: r = -0.58, P < 0.01; tibia: r = -0.53, P = 0.01) in merged control-CKD patients. Hemoglobin was negatively correlated with tissue sodium concentrations in CKD (soleus: r = -0.65, P = 0.02; tibia: r = -0.73, P < 0.01) and HD (skin: r = -0.60, P = 0.04; tibia: r = -0.76, P < 0.01).
Tissue sodium concentrations, measured by 23Na MRI, increase in HD and PD patients and may be associated with adverse metabolic effects in CKD and dialysis.
钠-23磁共振成像（23Na MRI）可直接测量组织钠浓度。目前对于慢性肾脏病（CKD）及接受肾脏替代治疗患者的皮肤、肌肉和骨骼钠浓度的了解有限。在本研究中，我们通过小腿的23Na MRI测量了CKD、血液透析（HD）和腹膜透析（PD）患者的组织钠浓度，并探讨了它们与既定临床生物标志物的相关性。
10名健康对照者、12名CKD 3-5期患者、13名HD患者和10名PD患者接受了腿部的质子和23Na MRI检查。手动分割皮肤、比目鱼肌和胫骨，并测量组织钠浓度。从每个受试者采集血浆和血清样本，并分析常规临床生物标志物。比较各组之间的组织钠浓度，并探讨与血液生物标志物的相关性。
与对照组相比，HD和PD患者皮肤、比目鱼肌和胫骨的组织钠浓度更高。血清白蛋白与HD患者比目鱼肌钠浓度呈强负相关（r = -0.81，P < 0.01）。在合并的对照-CKD患者中，估计肾小球滤过率与组织钠浓度呈负相关（比目鱼肌：r = -0.58，P < 0.01；胫骨：r = -0.53，P = 0.01）。血红蛋白与CKD（比目鱼肌：r = -0.65，P = 0.02；胫骨：r = -0.73，P < 0.01）和HD（皮肤：r = -0.60，P = 0.04；胫骨：r = -0.76，P < 0.01）患者的组织钠浓度呈负相关。
通过23Na MRI测量的组织钠浓度在HD和PD患者中升高，可能与CKD和透析中的不良代谢效应相关。
