Masked hypertension and hidden uncontrolled hypertension after renal transplantation

Arterial hypertension is a risk factor affecting graft function in pediatric kidney transplants. Recent pediatric studies reported a high prevalence of hypertension, especially nocturnal hypertension in this population. Data regarding the prevalence of masked hypertension in pediatric patients with kidney transplants are still scarce. The aim of this cross-sectional study was to assess the prevalence of masked and hidden uncontrolled hypertension after renal transplantation. A total of 41 patients (25 males) with stable functioning renal graft were included in the study. Their median age was 14.5 years with the median interval since transplantation of 2.5 years (range 0.3 to 20.6). Spacelabs 90207 was used to measure ambulatory blood pressure (BP) during a 24-h period. Ambulatory hypertension was defined as mean systolic and/or diastolic BP index at day-time or nighttime >or=1. Masked hypertension was defined as normal office BP but daytime ambulatory hypertension in patients without antihypertensive medications. Hidden uncontrolled hypertension was defined as daytime ambulatory hypertension undetected by office BP measurements in treated patients. Antihypertensive medications were prescribed to 58%. Prevalence of nocturnal hypertension was 68%. On the basis of combination of office and ABPM masked hypertension and hidden uncontrolled hypertension was detected in 24% and 21% of the study population, respectively. Regular use of ambulatory blood pressure monitoring in transplanted patients enables detection of masked and hidden uncontrolled hypertension.