Nocturnal blood pressure elevation in transplanted pediatric patients.

Ambulatory blood pressure monitoring during 24 hours was applied in 34 pediatric patients aged 6.3 to 24.3 (median 14.0) years who had been transplanted 0.3 to 8.4 years previously. The mean arterial blood pressure levels measured during the daytime and at night correlated positively (r = 0.70), but 14 of the 28 patients with nocturnal hypertension were normotensive during the day. A reduced nocturnal dip (< 5.5%) of mean arterial blood pressure was detected in 11 of 34 patients. In the first year post-transplantation 4 of 7 patients had an attenuated dip without any obvious cause. Beyond the first year a reduced dip was always associated with a renal pathology. In conclusion, a high prevalence of nocturnal hypertension was detected in grafted pediatric patients, even in presence of normal daytime blood pressures. An attenuated nocturnal dip was found in association with an underlying renal pathology or within the first post-transplant year.