Elevated pulse pressure and disturbed circadian blood pressure profile are risk factors for organ damage of arterial hypertension. The aim of the study was to evaluate of prevalence of elevated pulse pressure and disturbed circadian blood pressure profile in children with IgA nephropathy (IgAN) and Schoenlein-Henoch nephropathy (SHN).
Material and methods: 48 children (27 males and 21 females) with IgAN (n=21) and SHN (n=27) aged from 4.5 to 19 mean 13.3 years were enrolled into the study. In all patients ambulatory blood pressure monitoring (ABPM) was performed. In detail pulse pressure during 24 hours, activity and rest period (PP/24 h, PP/a, PP/r) as index PP (PPI) and circadian blood pressure profile were analyzed. In all patients BMI Z-score, hypertensive medications, GFR according to Schwartz formula and serum uric acid level were evaluated.
Results: Elevated pulse pressure was found in 17 (35.42%) patients: in 11 with SHN and in 6 with IgAN. In patients without antihypertensive treatment (n=18) positive correlations between PPI/24 h, PPI/a and serum uric acid level (r=0.59; r=0.48; p<0.05 respectively) and between PPI/24, PPI/a and BMI-Z score (r=0.57; r=0.50; p<0.05 respectively) were demonstrated. Disturbed circadian blood pressure profile was found in 13 (27.1%) patients; 11 patients with disturbed blood pressure profile did not have hypertension in ABPM. 6 patients had disturbed blood pressure profile despite antihypertensive treatment. Kidney function was normal in all patients.
Conclusions: Disturbed circadian blood pressure profile is a common phenomenon in children with IgAN and SHN also in normotensive patients and in patients on antihypertensive treatment. Elevated uric acid serum level may be a marker of elevated pulse pressure in children with IgAN and SHN.