Abnormal 24-hour blood pressure patterns in children after renal transplantation.

Hypertension after renal transplantation occurs commonly and is associated with decreased allograft survival. Hypertension is usually diagnosed by casual blood pressure (BP) measurements in the outpatient clinic that may not reflect the overall 24-hour BP pattern. To better describe the pattern of BP in children after renal transplantation, 24-hour ambulatory BP monitoring (APBM) was performed in 42 patients with stable renal function. BP was measured every 20 minutes during the daytime and every 30 minutes at night. Mean patient age was 12.8 +/- 5.2 years, and mean time after transplantation was 34 +/- 36 months. Seventy-six percent of the patients were administered antihypertensive medications. Twenty-four-hour mean systolic BP (SBP) was 127 +/- 11 mm Hg, and diastolic BP (DBP) was 80 +/- 11 mm Hg. Mean 24-hour BP load values (percentage of BP readings > 95th percentile based on Task Force criteria) were 59% for SBP and 50% for DBP, which were significantly elevated compared with healthy children (P < 0.001). An attenuated decline in sleep BP (nondipping) was found in 78% of the patients for SBP and 50% for DBP. Sleep BP exceeded awake BP in 24% of the patients for SBP and 17% for DBP. Boys had a greater SBP load (66% versus 45%; P = 0.03) and DBP load (57% versus 38%; P = 0.04) than girls. These results confirm in children the high prevalence of hypertension by ABPM criteria after renal transplantation and show attenuation of normal sleep BP decreases. These BP disturbances may shorten renal allograft survival and predispose children to long-term hypertensive end-organ damage.