Study on Etiology of Hypertension in Patients on Chronic Hemodialysis

In order to study the role of renin-angiotensin-aldosterone system and sympathetic nervous system in patients with hypertension on chronic hemodialysis, plasma renin activity, plasma aldosterone concentration and serum dopamine-β-hydroxylase activity were measured in 15 patients during hemodialysis. The plasma renin activity and mean blood pressure were significantly higher in patients with uncontrollable hypertension than in patients with controllable hypertension by hemodialysis. Plasma aldosterone concentrations ranged from subnormal to excessively elevated values and correlated significantly with serum potassium levels before and after hemodialysis. Serum dopamine-β-hydroxylase activity, one of the parameters of sympathetic nervous function, was supressed and less changeable before and after hemodialysis. From the above results, it is suggested that the renin-angiotensin system may play an important role in the etiology of uncontrollable hypertension and that in terminal renal failure plasma aldosterone may be mainly regulated by serum potassium levels. On the other hand, sympathetic nervous system appears to have no significant role in hypertension seen in terminal renal failure.