Effect of haemodialysis on plasma ADH levels, plasma renin activity and plasma aldosterone levels in patients with end-stage renal disease.

Changes in plasma ADH levels and plasma aldosterone levels (PA) were studied in patients with end-stage renal disease (N = 40). The patients were divided into two groups according to their plasma renin activity (PRA) into a low renin (LR, n = 9) and a high renin group (HR, n = 31). The metabolic clearance rate (MCR) of plasma ADH was also investigated in 4 patients and 5 normal volunteers. Additionally, it was examined whether plasma ADH, aldosterone and renin were permeable through the dialysis membrane. Pre- and post-dialysis plasma ADH levels in LR were similar to those in the HR group. However, pre- and post-dialysis PA in the HR group were significantly greater than those in the LR group. Post-dialysis PRA was significantly increased in HR compared to pre-dialysis, but not in LR. Pre- and post-dialysis plasma osmolality was increased in both groups, but effective plasma osmolality (EPosm) was within the normal range. There was a significant correlation between EPosm and plasma ADH level both before and after haemodialysis, but the majority of the abnormally high values of ADH compared to the normal values was found within the normal range of EPosm. The patients exhibited high blood pressure and a rise in body weight, and haemodialysis caused a significant fall in body weight and blood pressure in both groups. MCR of ADH was significantly lower in the patients than that in normal subjects. Plasma ADH proved to be permeable through the dialysis membrane in all cases, but aldosterone in only a few cases. Renin was not permeable.