Blood pressure, circulating renin and the body sodium/volume state in patients with mild renal failure.

Hypertensive patients with various renal lesions and a mean plasma creatinine of 2mg/100ml showed increases (p is less than 0.05) in mean exchangeable sodium and plasma renin activity, while blood volume was not altered significantly. Patients with mild renal failure and normal blood pressure demonstrated no consistent abnormalities in these parameters. Blood pressure correlated significantly with exchangeable sodium and with the 'sodium-renin' and 'blood volume-renin' products; but not with circulating renin or volume individually. This suggests that subtle abnormalities in the physiological sodium/volume-renin feedback mechanism may occur already in the earliest stages of renal disease and may contribute to the hypertension in such patients.