Nocturnal hypertension in renal failure, haemodialysis and after renal transplantation.

Diurnal blood pressure variations in 20 patients with advanced renal failure, 20 patients on chronic haemodialysis, and 21 renal transplant recipients were compared with those of matched control groups without renal disease, using 24-h ambulatory blood pressure monitoring. Whereas the blood pressure during the day (from 8 a.m. to 8 p.m.) was roughly the same in the patients compared with their respective control groups, during the night (from 8 p.m. to 8 a.m.) it was substantially higher in all patient groups. The differences between the mean daytime and night-time values were significantly lower in the patients (P less than 0.05 to P less than 0.001). The nocturnal blood pressure decrease may be attenuated or even reversed in renal failure, in haemodialysis and after renal transplantation. In a proportion of these patients, 24-h ambulatory blood pressure monitoring showed an elevated nocturnal blood pressure, which may require some modification of treatment.