Systemic Blood Pressure Parameters Research Articles

Retinal Microvascular Reactivity in Chronic Cigarette Smokers and Non-smokers: An Observational Cross-Sectional Study.

Purpose: To evaluate the changes in the retinal microvasculature and its reactivity in chronic cigarette smokers.Methods: Thirty-four male chronic cigarette smokers and 18 male non-smokers were enrolled. Optical coherence tomography angiography was used to measure the perfused retinal vessel densities (PVDs) of the peripapillary and parafoveal areas at baseline and during phase IV of the Valsalva maneuver (VM-IV). Systemic blood pressure and intraocular pressure were also measured.Results: The baseline PVD in the peripapillary area of the smokers was significantly lower than the non-smokers (59.56 ± 2.26% vs. 61.67 ± 3.58%, respectively; P = 0.005). However, there was no significant difference in the foveal avascular zone or parafoveal PVD between the two groups. During VM-IV, the peripapillary PVD of the smokers decreased by 1.13 ± 3.50%, which was significantly less than that of the non-smokers (−3.83 ± 4.26%, P < 0.05). Similarly, the parafoveal PVD of the smokers decreased by 5.49 ± 9.70%, which was significantly less than the percentage change of the non-smokers (−13.01 ± 8.39%, P < 0.05). There was no significant difference in the percentage change in systemic blood pressure parameters between the two groups.Conclusion: The retinal microvasculature and its reactivity were impaired in chronic smokers compared with non-smokers. The extent of impairment differed among different regions of the fundus.

Associations between systemic blood pressure parameters and intraplaque hemorrhage in symptomatic intracranial atherosclerosis: a high-resolution MRI-based study.

The associations between blood pressure parameters and intracranial vulnerable plaques have not been fully elucidated. The purpose of this study was to investigate the associations between systemic blood pressure parameters, as well as their variability, and intraplaque hemorrhage (IPH) in stroke patients with intracranial atherosclerosis. We retrospectively analyzed the high-resolution MRI data set of intracranial atherosclerosis from a comprehensive stroke center. The atherosclerotic plaque burden and presence of IPH in each vessel were obtained from vessel wall imaging. Blood pressure parameters in the first week of admission were used. The systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and their variability (standard deviation [SD] and coefficient of variation [CV]) were compared between the IPH (+) and IPH (-) groups. Logistic regression analysis was used to demonstrate the correlations between different blood pressure parameters and IPH. The results indicated that SBP and PP were associated with multiple plaques and severe luminal stenosis after adjusting for confounders, with OR = 1.071, 95% CI: (1.044-1.098) and OR = 1.039, 95% CI: (1.019-1.060) for SBP and OR = 1.058, 95% CI: (1.027-1.089) and OR = 1.044, 95% CI: (1.019-1.070) for PP, respectively. SBP was associated with IPH after adjusting for cardiovascular risk factors, with OR = 1.021, 95% CI: (1.003-1.038), but not after correcting for plaque burden, with OR = 1.014, 95% CI: (0.996-1.032). No associations between blood pressure variability and atherosclerotic plaque burden or IPH were detected in this study. In conclusion, SBP is associated with IPH after adjusting for cardiovascular risk factors but not after further correction for atherosclerotic plaque burden. The association between blood pressure variability and intracranial atherosclerosis requires further study.

Analysis of Retinal Vessel Pulsation with Electrographic Gating - Pulsation Amplitude and the Influence of Hyperoxia.

To analyse the amplitude of vessel pulsation in the retina and to determine whether constriction of the vessels by oxygen would decrease their pulsation amplitude and could thus be used to quantify the rigidity of the retinal vessels. The study included 20 healthy young subjects. With the RVA (retinal vessel analyser), we aimed to quantify vessel pulsations under normal and hyperoxic conditions. Electrocardiographic (ECG)-gated RVA was used for this purpose, with change in vessel pulsation as the primary endpoint and shift in vessel pulsation during the heart cycle as the secondary endpoint. Furthermore, we assessed the correlation between the amplitude of retinal vessel wall pulsation and blood pressure. Descriptive statistics, paired t-tests, and correlation analysis were applied. Retinal veins in proximity to the optic disc demonstrated the highest pulsation amplitude under all conditions. All retinal vessels significantly constricted under hyperoxic conditions. There was no significant change in the amplitude of vessel pulsation nor a significant shift in the pulsation cycle under hyperoxic conditions in the examined cohort. No correlation was found between systemic blood pressure parameters and amplitude of retinal vessel wall pulsation or any change in this. ECG-gated RVA recording is not able to detect any relevant change in vessel pulsation behaviour under oxygen, despite clearly observed vasoconstriction in retinal vessels. New approaches are necessary to reliably quantify the rigidity of the retinal vessels.

Macular Pigment Optical Density is Related to Blood Glutathione Levels in Healthy Individuals

To assess the relationship between macular pigment optical density (MPOD) and blood markers for antioxidant defense in otherwise healthy volunteers. Forty-seven healthy volunteers were subjected to blood analysis to detect the level of circulating glutathione in its reduced (GSH) and oxidized (GSSG) forms. The level of MPOD was measured using heterochromatic flicker photometry. Systemic blood pressure (BP) parameters, heart rate (HR), body mass index (BMI), and plasma levels of total, HDL, and LDL cholesterol and triglycerides (TGs) were also determined. A simple correlation model revealed that the level of MPOD correlated significantly and positively with both GSH (P < 0.001) and t-GSH (P < 0.001) levels but not with those of GSSG (P > 0.05). Age, sex, systemic BP parameters, HR, BMI, and plasma levels of cholesterol and TGs did not have any influence on either MPOD or glutathione levels (all P > 0.05). In addition, a forward stepwise multiple regression analysis showed MPOD to have a significantly and independent correlation with GSH levels (β = 0.63; P < 0.001). In otherwise healthy older individuals, there is a positive correlation between local and systemic antioxidant defense mechanisms.