Arterial stiffness in children with primary hypertension is related to subclinical inflammation

Introduction
The immune system can trigger an inflammatory process leading to blood pressure elevation and arterial damage. The aim of the study was to assess the relation between subclinical inflammation and arterial damage in pediatric patients with primary hypertension (PH) and to establish the usefulness of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios, and mean platelet volume (MPV) as markers of arterial damage in these subjects.

Material and methods
In 119 children with PH (14.94 ±2.76 years) and 45 healthy children (14.91 ±2.69 years) we analyzed markers of subclinical inflammation (NLR, PLR, MPV), clinical and biochemical parameters, office blood pressure, ambulatory blood pressure monitoring (ABPM), central blood pressure, aortic pulse wave velocity (aPWV), augmentation index corrected for heart rates 75 (AIx75HR), carotid intima media thickness (cIMT), and common carotid artery stiffness (E-tracking).

Results
Children with PH were characterized by significantly higher neutrophil (3.9 ±1.7 vs. 3.0 ±1.0 [1000/µl], p < 0.001) and platelet counts (271.9 ±62.3 vs. 250.3 ±60.3 [1000/µl], p = 0.047), NLR (1.9 ±1.5 vs. 1.3 ±0.4, p = 0.010), PLR (131.4 ±41.9 vs. 114.7 ±37.6, p = 0.020), aPWV (5.36 ±0.88 vs. 4.88 ±0.92 m/s, p = 0.004), and cIMT (0.46 ±0.07 vs. 0.43 ±0.07 mm, p = 0.002) compared to healthy children. In PH children NLR correlated positively (p < 0.05) with: systolic, diastolic and mean blood pressure in ABPM (r = 0.243, r = 0.216, r = 0.251), aPWV [m/s] (r = 0.241), aPWV Z-score (r = 0.204), and common carotid artery PWVbeta [m/s] (r = 0.202).

Conclusions
There is a link between arterial stiffness and subclinical inflammation in pediatric patients with primary hypertension. Neutrophil-to-lymphocyte ratio may serve as a promising marker of arterial stiffness in pediatric patients affected by primary hypertension.