Abstract
Background/Objectives: Increased blood pressure variability (BPV) was found in adults with primary (essential) hypertension (PH) and is associated with increased cardiovascular risk. Our study aimed to analyze the relation between BPV and low-grade inflammation in children with primary hypertension. Methods: In 56 treatment-naive pediatric patients with PH (15.1 ± 2.1 years) and 30 healthy children (14.9 ± 1.4 years), we evaluated BPV: BP dipping, standard deviation (SD) of ambulatory blood pressure measurements (ABPMs), pulse pressure (PP)/systolic blood pressure ratio (24 h PP/SBP), rate-pressure index (24 h RPI), 24-h weighted BPV (24 h WSBPV, 24 h WDBV, 24 h WMAPV), coefficient of variation (24 h CoVSBP, 24 h CoVDBP, 24 h CoVMAP), ambulatory arterial stiffness index (AASI), and morning BP surge. We also analyzed indices of subclinical inflammation (markers derived from complete blood count, high-sensitivity C-reactive protein (CRP), interleukin 18), and office and ambulatory BP. Results: Patients with PH had significantly higher hsCRP, neutrophils, monocytes, and platelets, neutrophil-to-lymphocyte (NLR), platelet-to-mean platelet volume (PMPVR), and lower monocyte-to-neutrophil (MNR) ratios, and higher BPV: 24 h ABPM SBP SD, 24 h ABPM MAP SD, 24 h RPI, 24 h WSBPV, 24 h WDBV, 24 h WMAPV, and 24 h CoVSBP. Low-grade inflammation markers correlated with BPV indices in both groups. In multivariate analysis, MNR predicted 24 h ABPM MAP SD (beta = 0.290, 95CI: 0.029-0.551), 24 h RPI (beta = -0.348, 95CI: -0.587--0.108), and 24 h WDBPV (beta = 0.286, 95CI: 0.032-0.540); monocyte count-24 h RPI (beta = 0.281, 95CI: 0.041-0.521), and hsCRP-24 h WDBV (beta = 0.310, 95CI: 0.055-0.564). ROC analysis revealed a good diagnostic profile for lymphocyte count as a positive determinant of non-dipping status in PH children (cut-off point 2.59 [×10(3)/µL]). Conclusions: BPV is higher in children with PH compared to healthy peers and is associated with low-grade inflammation. MNR may be the most helpful indicator of BPV, whereas high lymphocyte count predicts the best non-dipping status in these patients.