Histopathological changes of radial artery wall in patients of chronic kidney disease stage 5 undergoing AV fistula formation and their correlation with serum iPTH levels.

Vascular complications arise in uremic patients in the absence of clinically significant atherosclerotic disease. Elevated serum parathyroid hormone (PTH) and abnormal calcium (Ca) and phosphorus (P) balance have been implicated in vascular damage in chronic kidney disease (CKD) patients, but there is lack of histo-pathological studies. Patients with CKD stage 5 and 5D who underwent arterio-venous fistula were included in this study. Baseline and laboratory parameters including assessment of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, uric acid, albumin, calcium, phosphorus, intact PTH (iPTH) and vitamin D level were documented. The specimens of the arterial wall were obtained during the procedure and were analyzed. Patients were divided into two groups iPTH <400 (Group A) and iPTH >400 (Group B). Mean intimal thickness (IT) was significantly high in patients of Group B (60.4 ± 24.1 μ m) as compared with patients of Group A (37.8 ± 14.9 μm) (P = 0.003). Vascular calcification was comparable in both groups. The iPTH level was found to be an independent risk factor for high intima thickness (correlation coefficient 0.653) (P-value <0.01). Patients with high (≥ 400 pg/mL) iPTH have 8.93 times the risk of developing intimal thickness of ≥ 60 μ m as compared with patients with low (<400 pg/mL) iPTH (P-value <0.05), with 95% confidence interval of 1.27, 62.61. The mean IT of the radial artery significantly correlated with the iPTH level, while vascular calcification was independent of the iPTH level. Hyperparathyroidism is an important cause of ongoing vascular damage and may contribute to higher vascular events in CKD patients.