A comparison between office and ambulatory blood pressure measurements in renal transplant patients with chronic transplant nephropathy

Hypertension is an important risk factor for chronic transplant nephropathy. Therapy is usually based on casual office blood pressure (BP) measurements. However, it is not well known how casual BP predicts 24-hour BP in this population. The main focus of this study is to compare casual office BP with 24-hour ambulatory BP monitoring in renal transplant recipients with signs of chronic transplant nephropathy. Moreover, in this group, the day-night BP profile was assessed. In 36 renal transplant recipients with incipient or progressive proteinuria or an increase in serum creatinine level greater than 20%, 24-hour ambulatory BP was performed. Patients were defined as a nondipper if the mean BP decreased by less than 10% during the nighttime period. The correlation between single office and 24-hour ambulatory BPs was 0.61 for systolic BP and 0.55 for diastolic BP (P < 0.001). The mean difference between 24-hour ambulatory and single office BPs was -4.2 +/- 18.6 mm Hg (range, -44 to 36 mm Hg) for systolic BP and -1.1 +/- 10.7 mm Hg (range, -34 to 27 mm Hg) for diastolic BP; 94.5% of patients were classified as nondippers. There was a significant relation between the nightly decline in mean arterial pressure and calculated creatinine clearance (r = 0.34; P < 0.05). In conclusion, in renal transplant recipients with chronic transplant nephropathy, a large difference between office and ambulatory BPs is present, with both overestimation and underestimation of 24-hour BP by office BP measurements. Moreover, a severely disturbed day-night BP rhythm was observed. In transplant recipients with compromised graft function, office BP may not reflect 24-hour BP adequately, and ambulatory BP measurements should be considered. (C) 2001 by the National Kidney Foundation, Inc.