Introduction: Hypertension (HT) is one of the major risk factors of chronic kidney disease (CKD) progression and cardiovascular complications. The aim of the study was to analyze blood pressure (BP) values and assess the usefulness of clinical measurements in BP monitoring in children with chronic kidney disease.
Material and methods: The study was conducted in 62 children (40 boys and 22 girls) aged 4,2-18,6 years (median age 12.4 (9.1; 16.0) with CKD stages 1 + 2 (n = 9), 3 (n = 17), 4 (n = 15) and 5. Creatinine concentration was measured and glomerular filtration rate was calculated using the Schwartz formula. Each of the patients underwent clinical BP measurements and 24-hour ambulatory blood pressure monitoring (ABPM).
Results: Based on clinical meaurements elevated BP values were found in 25 patients (40.3%): in stages 1 + 2 in 33.3%, in stage 3 in 41.2%, in stage 4 in 46.6% and in stage 5 in 38.1% patients. Hypertension was diagnosed with ABPM in 30 patients (48.4% of the studied population): in stages 1 + 2 - 3 patients (33.3%), in stage 3 - 8 patients (47, 1%), in stage 4 - 7 patients (46.7%) and stage 5 - 12 patients (57.1%). Only 12 patients (19.4%) had hypertension diagnosed in both clinical and ABPM measurements. White coat effect was found in 13 children (21.0%) and masked HT in 18 children (29.0%). In 24-hour BP monitoring the highest values of systolic, diastolic and mean BP values were found in children with masked HT. In children with masked HT higher values of 24-hour systolic (120 vs. 105.5 mmHg, p<0.001) and diastolic (75 vs. 65 mmHg, p<0.001) BP compared with clinical values were detected. Children with masked HT had significantly higher nighttime diastolic BP compared with children with HT (1.43 vs. 0.74 z-score, p<0.001).
Conclusions: The large percentage of children with masked hypertension is an indication for frequent ABPM measurements in children with chronic kidney diseses. Office measurements are not sufficient to detect HT in children with CKD. The best diagnostic method to confirm and monitor hypertension in patients with CKD is 24-hour ambulatory blood pressure monitoring.