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

Evaluation of Mean Platelet Volume in Children with Hypertension

Background

Childhood hypertension, a disease with increasing prevalence, can lead to severe health problems. With the increased pressure on the vascular endothelium in hypertension, lesions in the endothelium result in endothelial activation and a process of inflammation, which causes platelet activation and in the bone marrow the release of platelet precursor cells into the peripheral blood stream. During inflammation, changes in the number and size of platelets are observed. With the release of platelet precursors into the peripheral blood stream due to platelet activation, an increase in mean platelet volume (MPV) is also seen.

Aim

Our aim in this study is the evaluation of MPV changes in the hemogram of children suffering from hypertension, a condition causing severe cardiovascular problems. Material and Methods. This research is a descriptive retrospective cross-sectional study. It consists of a patient group diagnosed with hypertension and a control group of children presenting for routine check-ups with no diagnosed hypertension. Demographic characteristics, arterial pressure values, and hemogram parameters have been evaluated.

Results

A total of 90 cases were enrolled in the study, including a patient group of 45 cases with hypertension (19 females, 26 males) and a control group of 45 cases (27 females, 18 males). The median age was 15 years in the hypertension group and 13 years in the control group. In the hypertension cases, the thickness of the carotis intima media was statistically significantly greater than in the control group (p < 0.001). Echocardiographic findings (IVSd, LVDd, LVPWd, IVSs, LVDs, LVPWs, and LV mass) were significantly higher in the hypertension group compared to the control group (p < 0.001). A statistically significant difference in platelet count and MPV values between the groups was not found (p = 0.151, p = 0.405, respectively).

Conclusion

While MPV is hypothesized to be higher in hypertensive individuals, there was no statistically significant difference between the hypertensive and non-hypertensive groups in this study.

Immunological mechanisms of arterial damage in pediatric patients with primary hypertension

Primary hypertension is a disease that is being diagnosed with increasing frequency in pediatric patients, and many of them are found to have hypertension-mediated organ damage (HMOD), including arterial damage. The pathophysiology of primary hypertension and the formation of HMOD is multifactorial. One mechanism studied in recent years is the subclinical inflammation accompanying the elevation of blood pressure. Experimental studies, studies in adults and children, revealed the involvement of immune mechanisms in the formation of vascular lesions in the course of primary hypertension. The paper summarizes the current knowledge on this subject and points to possible therapeutic targets. Particular emphasis is placed on data from pediatric patients with primary hypertension, as a relation between arterial damage (early vascular aging) and immune system activation had already been found in children. The correct identification of immunological mechanisms may not only broaden our understanding of primary hypertension as a disease but also, more importantly, lead to the most effective methods of its treatment.

Association between red blood cell distribution width and left ventricular hypertrophy in pediatric essential hypertension

AIM

Left ventricular hypertrophy (LVH) is one of the most common types of target organ damage in hypertension. The red blood cell distribution width (RDW) is closely related to many cardiovascular diseases, including hypertension. The aim of this study was to analyze the relationship between the RDW level and LVH in pediatric essential hypertension.

MATERIALS AND METHODS

A total of 429 untreated children and adolescents with essential hypertension were recruited and divided into an LVH group (n = 114) and non-LVH group (n = 315) according to left ventricular mass index (LVMI) and relative wall thickness (RWT) by color Doppler ultrasound. Spearman correlation analysis was used to determine the relationship between RDW and LVMI, RWT. The effect of RDW on LVH was determined using a multivariate logistic regression analysis. To assess the predictive value of RDW on LVH, the receiver operating characteristic (ROC) curve was used.

RESULTS

The level of RDW in children with hypertension in the LVH group was significantly higher than that in the non-LVH group (13.0 [12.0, 13.0] vs. 12.4 [12.0, 13.0] %, P = 0.001). The incidence of low and high quantiles of LVH was 21.0% and 32.0%, respectively. Spearman correlation analysis showed that RDW was positively correlated with C-reactive protein (CRP), LVMI, RWT, and red blood cell (RBC) count (P all < 0.05), and negatively correlated with hemoglobin (HGB) level, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) (P all < 0.05). After adjusting for various confounding factors, a multivariate logistic regression model revealed that RDW was an independent risk factor for LVH (OR = 1.946, 95% CI: 1.324-2.861, P = 0.001). The area under the ROC curve of RDW predicting centripetal hypertrophy was 0.700 (95% CI: 0.541-0.859, P < 0.05) in pediatric essential hypertension.

CONCLUSIONS

Increased RDW levels are an independent risk factor for LVH in pediatric essential hypertension, and RDW may be a predictor of LVH in untreated pediatric essential hypertension.

Transplantation of bone marrow cells from miR150 knockout mice improves senescence-associated humoral immune dysfunction and arterial stiffness

BACKGROUND AND PURPOSE

The senescence-accelerated mouse P1 (SAMP1) suffers from humoral immune deficiency, arterial stiffness and accelerated aging. In contrast, the microRNA-150 knockout (miR-150-KO) mice show enhanced humoral immune function including increased B cell population and elevated serum immunoglobulin levels and enjoy extended lifespan. The purpose of this study was to investigate whether transplantation of bone marrow cells (BMCs) from miR-150-KO mice affects immune deficiency and arterial stiffening in SAMP1 mice.

METHODS AND RESULTS

Pulse wave velocity and blood pressure were increased significantly in SAMP1 mice (10 months), indicating arterial stiffening and hypertension. Interestingly, transplantation of BMCs from miR-150-KO mice significantly attenuated arterial stiffening and hypertension in SAMP1 mice within eight weeks. BMC transplantation from miR-150-KO mice partially rescued the downregulation of B lymphocytes, largely restored serum IgG and IgM levels, decreased inflammatory cytokine and chemokine expression, and attenuated macrophage and T cell infiltration in aortas in SAMP1 mice. BMC transplantation nearly abolished the upregulation of collagen 1, TGFβ1, Scleraxis, MMP-2 and MMP-9 expression and the downregulation of elastin levels in aortas in SAMP1 mice. FISH staining confirmed existence of the transplanted BMCs at end of the experiment. In cultured endothelial cells, IgG-deficient medium invoked upregulation of inflammatory cytokine/chemokine expression which can be rescued by treatment with IgG.

CONCLUSIONS

Accelerated senescence caused arterial stiffening via impairing the humoral immune function in SAMP1 mice. BMC transplantation from miR-150-KO mice attenuated arterial matrix remodeling and stiffening and hypertension in SAMP1 mice partly via improving the humoral immune function which attenuates vascular inflammation.

24-hour central blood pressure and immune system activation in adolescents with primary hypertension - a preliminary study

Introduction

Adult and pediatric data suggest a positive relationship between the extent of subclinical inflammation, blood pressure, and hypertension-mediated organ damage (HMOD) in primary hypertension (PH). 24-hour (24-h) ambulatory blood pressure (ABPM) and central blood pressure (CBP) are strong predictors of HMOD. Our study aimed to analyze the relationship between 24-h central ABPM, subclinical inflammation, and clinical data in adolescents with PH.

Material and methods

In 28 untreated adolescents with PH (14.50 ±2.27 years) and 25 healthy peers (14.76 ±2.83 years), we analyzed 24-h peripheral and central ABPM, markers of subclinical inflammation (neutrophil-to-lymphocyte ratio - NLR, platelet-to-lymphocyte ratio - PLR, mean platelet volume - MPV), and clinical and biochemical data.

Results

Patients with PH had higher 24-h peripheral and central blood pressure than healthy peers. In all 53 patients, we found significant (p < 0.05) positive correlations between NLR, PLR and 24-h central systolic, diastolic, and mean blood pressure (24-h cSBP, 24-h cDBP, 24-h cMAP), between 24-h central augmentation index corrected for heart rate 75 (24-h cAIx75HR) and platelet count. In 28 patients with PH, 24-h cAIx75HR correlated with low-density lipoprotein (LDL) cholesterol (R = 0.442), and ambulatory arterial stiffness index with body mass index (BMI) (R = 0.487), uric acid (R = 0.430), and high-density lipoprotein (HDL) cholesterol (R = -0.428).

Conclusions

Increased central 24-h blood pressure may be associated with immune system activation in adolescents with primary hypertension. In adolescents with primary hypertension, dyslipidemia and hyperuricemia are risk factors for increased arterial stiffness. Further studies on central and peripheral blood pressure in terms of their relationship with inflammation in these patients are needed.