Early Vascular Aging: A New Target for Hypertension Treatment.

Vascular aging represents a progressive procedure involving biochemical, enzymatic, and cellular changes of the vascular tree. Early vascular aging (EVA), is defined as the inappropriate for age of vascular damage. Increased for age arterial stiffness is a biomarker that should be considered as a cardiovascular (CV) risk factor that can be manipulated. EVA is a new tool for guidance in everyday clinical praxis for patients at increased CV risk or a positive family history of early onset of cardiovascular events, such as stroke or coronary artery disease. Understanding the mechanisms promoting or protecting from EVA, a process that is in close relationship with CV diseases. The role of hypertension treatment against the development of vascular damage is important and different strategies could have a considerable impact on future vascular health.

Arterial stiffness and SBP variability in children and adolescents.

BACKGROUND: The aim of this study was to explore the impact of ambulatory blood pressure (ABP) parameters on arterial stiffness measured by carotid-femoral pulse wave velocity (cf-PWV) in children and adolescents. METHOD: The study population consisted of 138 consecutive young patients (age range 4-20 years) referred to our hypertension center. Office blood pressure (BP), 24-h ABP monitoring and cf-PWV measurements were performed in all patients. Family history and smoking habits were also recorded. RESULTS: Among the study population, 10.6% had cf-PWV values equal to or higher than the 95th percentile of the study population. cf-PWV was higher in the hypertensive compared to the normotensive patients, classified by ABP levels even after adjustment for age and sex. Significant correlations were found between cf-PWV and age, weight, height, estimated central pulse pressure (PP), office SBP and DBP, and ABP parameters including 24-h SBP and DBP, weighted 24-h SBP variability, 24-h SBP and DBP load, 24-h mean arterial pressure (MAP), daytime and night-time SBP, daytime and night-time SBP variability, but not with office and 24-h heart rate, 24-h heart rate variability, 24-h daytime and night-time PP, DBP variability, ambulatory arterial stiffeness index and BMI z-score. In analysis of covariance, only weighted 24-h SBP variability (ß = 0.28, P < 0.05) and daytime SBP variability (ß = 0.15, P < 0.05) were the independent determinants of cf-PWV in children and adolescents. CONCLUSION: These data may suggest that increased SBP variability is closely associated with arterial stiffness in children and adolescents.

Arterial stiffness and 24 h ambulatory blood pressure monitoring in young healthy volunteers: the early vascular ageing Aristotle University Thessaloniki Study (EVA-ARIS Study).

Differences in 24 h blood pressure (BP) monitoring parameters such as average 24 h BP, day to night BP ratio and BP variability could have an impact in arterial stiffness. The study hypothesis was that despite similar average BP values in ambulatory blood pressure monitoring subjects with increased 24 h BP variability may have increased arterial stiffness. The study population consisted of 115 consecutive young healthy volunteers. Carotid-femoral PWV was measured in all subjects. Clinic BP was measured and an appropriate cuff was fitted on the non-dominant arm of each subject for a 24 h ambulatory blood pressure monitoring session. Waist to hip ratio as well as BMI was measured. Family history and smoking habits were recorded. In univariate analysis, estimated carotid-femoral PWV showed a significant correlation with age, weight, waist circumference, height, clinic systolic and diastolic BP, 24-h systolic and diastolic BP, 24-h pulse pressure, 24-h systolic and diastolic BP variability, daytime systolic and diastolic BP, daytime pulse pressure, daytime systolic and diastolic BP variability, nighttime systolic BP, nighttime pulse pressure and nighttime systolic BP variability. In multivariate regression analysis, age (B=0.95, P<0.001) and 24 h systolic BP variability (B=0.28, P<0.001) were independent determinanats of arterial stiffness. In conclusions, increased 24 h systolic BP variability is associated with arterial stiffness in young healthy volunteers. Pulse wave velocity in a young healthy population is useful to identify determinants of premature arterial stiffness, thus further elucidating the aspects of early vascular ageing.

The role of obesity, salt and exercise on blood pressure in children and adolescents.

The increasing trends of blood pressure (BP) in children and adolescents pose great concern for the burden of hypertension-related cardiovascular disease. Although primary hypertension in childhood is commonly associated with obesity, it seems that other factors, such as dietary sodium and exercise, also influence BP levels in children and adolescents. Several studies support that sympathetic nervous system imbalance, impairment of the physiological mechanism of pressure natriuresis, hyperinsulinemia and early vascular changes are involved in the mechanisms causing elevated BP in obese children and adolescents. Under the current evidence on the association of salt intake and BP, dietary sodium restriction appears to be a rational step in the prevention of hypertension in genetically predisposed children and adolescents. Finally, interventional studies show that regular aerobic exercise can significantly reduce BP and restore vascular changes in obese with hypertensive pediatric patients. This article aims to summarize previous studies on the role of obesity, salt intake and exercise on BP in children and adolescents.

Hypothyroidism and hypertension.

Hypothyroidism has been recognized as a cause of secondary hypertension. Previous studies on the prevalence of hypertension in subjects with hypothyroidism have demonstrated elevated blood pressure values. Increased peripheral vascular resistance and low cardiac output has been suggested to be the possible link between hypothyroidism and diastolic hypertension. The hypothyroid population is characterized by significant volume changes, initiating a volume-dependent, low plasma renin activity mechanism of blood pressure elevation. This article summarizes previous studies on the impact of hypothyroidism on blood pressure and early atherosclerotic process.

Mechanisms of obesity-induced hypertension.

The relationship between obesity and hypertension is well established both in children and adults. The mechanisms through which obesity directly causes hypertension are still an area of research. Activation of the sympathetic nervous system has been considered to have an important function in the pathogenesis of obesity-related hypertension. The arterial-pressure control mechanism of diuresis and natriuresis, according to the principle of infinite feedback gain, seems to be shifted toward higher blood-pressure levels in obese individuals. During the early phases of obesity, primary sodium retention exists as a result of increase in renal tubular reabsorption. Extracellular-fluid volume is expanded and the kidney-fluid apparatus is resetted to a hypertensive level, consistent with a model of hypertension because of volume overload. Plasma renin activity, angiotensinogen, angiotensin II and aldosterone values display significant increase during obesity. Insulin resistance and inflammation may promote an altered profile of vascular function and consequently hypertension. Leptin and other neuropeptides are possible links between obesity and the development of hypertension. Obesity should be considered as a chronic medical condition, which is likely to require long-term treatment. Understanding of the mechanisms associated with obesity-related hypertension is essential for successful treatment strategies.