Is there any true distinction in extreme dipping versus nondipping or dipping phenotype regarding hypertension-mediated organ damage in newly diagnosed and never-treated hypertensive patients?

Dipping phenomena is defined as nocturnal BP fall >10% during 24-h ambulatory blood pressure (BP) monitoring (ABPM) which carries a favorable cardiovascular risk (CVR) prognosis due to reduced 24-h hypertension burden. To date, extreme dipping phenotype (defined as BP decrease ≥20%) has led to controversial prognostic results regarding CVR. We aimed to explore hypertension-mediated organ damage (HMOD) in extreme dippers compared to the other dipping phenotypes (nondipping, dipping). From 490 consecutive patients with newly diagnosed never-treated arterial hypertension (mean age 51 ± 11 years, 294 males) subjected to 24-h ABPM, we studied 52 extreme dippers, 52 age- and gender-matched nondippers, and 52 age- and gender-matched dippers. All patients were subjected to arterial stiffness (PWV), 24-h microalbumin levels, carotid intima-media thickness (cIMT), diastolic dysfunction (E/Ea), and left ventricular mass index (LVMI) evaluation. ANOVA analysis found no differences regarding HMOD between groups. Multiple regression analysis revealed the following independent direct relationships between: (i) office SBP and PWV in nondippers (ß = 0.35, p = 0.01) and extreme dippers (ß = 0.49, p < 0.001), (ii) office SBP and E/Ea in extreme dippers (ß = 0.39, p = 0.007), (iii) 24-h diurnal and nocturnal SBP and E/Ea in dippers (ß = 0.40, p = 0.004, ß = 0.39, p = 0.005, and ß = 0.40, p = 0.004, respectively), and (iv) 24-h and nocturnal SBP and LVMI in nondippers (ß = 0.29, p = 0.04 and ß = 0.36, p = 0.009, respectively). In the early phases of untreated-arterial hypertension disease, extreme dipping phenotype in middle-aged hypertensives does not imply an adverse or favorable prognosis regarding the incidence of HMOD either as continuous variables or as abnormal HMOD compared to other dipping phenotypes.

Sex-related associations of high-density lipoprotein cholesterol with aortic stiffness and endothelial glycocalyx integrity in treated hypertensive patients.

Smoking, a well-recognized major cardiovascular (CV) risk factor, impairs endothelial function and increases aortic stiffness which indicates subclinical organ damage in hypertensive patients. Loss of endothelial glycocalyx (EG) integrity, as part of the endothelium, represents endothelial dysfunction. The authors aimed to investigate the role of increased HDL cholesterol levels (HDL-C), which usually are considered protective against CV disease, in aortic stiffness and endothelial integrity in middle-aged treated hypertensive patients regarding smoking habit. The authors studied 193 treated hypertensive patients ≥40 years (mean age = 61±11 years, 58% females), divided in four groups regarding sex and smoking. Increased perfusion boundary region of the 5-9 µm diameter sublingual arterial microvessels (PBR5-9 ) was measured as a noninvasive accurate index of reduced EG thickness. Aortic stiffness was estimated by carotid-femoral pulse wave velocity (PWV). In the whole population, an inverse weak relationship was found between HDL-C and PWV (r = -.15, P = .03) and PBR5-9 (ρ = -.15, P = .03). Moreover, HDL-C was negatively related to PBR5-9 in males (r = -.29, P = .008) either smokers (r = -.35, P < .05) or non-smokers (r = -.27, P < .05) and PWV in female non-smokers (r = -.28, P = .009). In a multiple linear regression analysis, using age, weight, smoking, HDL-C, and LDL-C as independent variables, we found that HDL-C independently predicts PWV in the whole population (ß = -.14, P = .02) and PBR5-9 in male hypertensive patients (ß = -.28, P = .01). Higher HDL-C levels are associated with reduced aortic stiffness in hypertensive patients, while they protect EG and subsequently endothelial function in middle-aged, treated hypertensive male patients (either smokers or not).

HDL cholesterol levels and endothelial glycocalyx integrity in treated hypertensive patients.

Endothelial dysfunction indicates target organ damage in hypertensive patients. The integrity of endothelial glycocalyx (EG) plays a vital role in vascular permeability, inflammation and elasticity, and finally to cardiovascular disease. The authors aimed to investigate the role of increased HDL cholesterol (HDL-C) levels, which usually are considered protective against cardiovascular disease, in EG integrity in older hypertensive patients. The authors studied 120 treated hypertensive patients older than 50 years were divided regarding HDL-C tertiles in group HDLH (HDL-C ≥ 71 mg/dL, upper HDL-C tertile) and group HDLL (HDL-C < 71 mg/dL, two lower HDL-C tertiles). Increased perfusion boundary region (PBR) of the sublingual arterial microvessels (ranging from 5 to 9 µm) using Sideview Darkfield imaging (Microscan, Glycocheck) was measured as a non-invasive accurate index of reduced EG thickness. PBR 5-9 was significantly decreased in group HDLH (P = 0.04). In the whole population, HDL-C was inversely but moderately related to PBR 5-9 (r = -0.22, P = 0.01). In a multiple linear regression analysis model, using age, BMI, smoking habit, HDL-C, LDL-C, and office SBP, as independent variables, the authors found that BMI (ß = 0.25, P = 0.006) independently predicted PBR 5-9 in the whole population. In older hypertensive patients, HDL-C ranging between 71 and 101 mg/dL might moderately protect EG and subsequently endothelial function. Future studies in several groups of low- or high-risk hypertensives are needed in order to evaluate the beneficial role of extremely elevated HDL-C regarding cardiovascular risk evaluation as well as endothelial glycocalyx as a novel index of target organ damage in essential hypertension.