Angiotensin Regulation of Vascular Homeostasis: Exploring the Role of ROS and RAS Blockers.

Extensive research has been conducted to elucidate and substantiate the crucial role of the Renin-Angiotensin System (RAS) in the pathogenesis of hypertension, cardiovascular disorders, and renal diseases. Furthermore, the role of oxidative stress in maintaining vascular balance has been well established. It has been observed that many of the cellular effects induced by Angiotensin II (Ang II) are facilitated by reactive oxygen species (ROS) produced by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In this paper, we present a comprehensive overview of the role of ROS in the physiology of human blood vessels, specifically focusing on its interaction with RAS. Moreover, we delve into the mechanisms by which clinical interventions targeting RAS influence redox signaling in the vascular wall.

Evening versus morning dosing of antihypertensive drugs in hypertensive patients with sleep apnoea: a cross-over study.

OBJECTIVE: Beneficial effects of continuous positive airway pressure (CPAP) on both blood pressure (BP) levels and variability have been documented in patients with obstructive sleep apnoea (OSA). We investigated the relevant impact of different dosing times of antihypertensive drugs beyond CPAP application. METHODS: In this prospective, cross-over trial, we included 41 patients with newly diagnosed hypertension and never treated OSA (apnoea-hypopnea index ≥15/h), without increased daytime somnolence (Epworth Score ≤10 points). Patients first received treatment with valsartan or with a fixed combination of amlodipine and valsartan in a single morning dose for 8 weeks. In the following 8-week period, patients received the same therapeutic regimen in a single evening dose. Office and ambulatory BP were measured at baseline and after each treatment period. RESULTS: Compared with morning administration, evening dosing induced a greater decrease in office SBP (by 3.7 ±â€Š6.5 mmHg, P = 0.001). The decrease in 24-h SBP/DBP was significant and similar after morning and evening dosing (-16.4 ±â€Š11/11.0 ±â€Š7.5 and -18.4 ±â€Š11/12.1 ±â€Š7.5 mmHg, respectively, P < 0.001 for both). Evening compared with morning dosing further reduced night-time SBP/DBP by 4.4 ±â€Š8.6/2.9 ±â€Š5.6 mmHg (P = 0.007 and P = 0.006, respectively). Night-time dippers increased from 24% at baseline to 34% with morning dosing and to 61% with evening dosing. There was no significant interaction between concurrent CPAP application and drugs dosing time on BP changes. CONCLUSION: Evening dosing of antihypertensive drugs improves night-time BP and dipping status in nonsleepy patients with OSA, irrespective of CPAP application.

Effects of continuous positive airway pressure on blood pressure in hypertensive patients with obstructive sleep apnea: a 3-year follow-up.

OBJECTIVE: Several studies have reported a small yet significant decrease in blood pressure (BP) with continuous positive airway pressure (CPAP) application in patients with obstructive sleep apnea (OSA). We investigated the long-term efficiency of CPAP in the management of hypertensive patients with OSA on top of conventional antihypertensive medication. METHODS: We followed 91 nonsleepy patients (aged 54 ± 9 years, 69 men) with essential hypertension and newly diagnosed moderate-to-severe OSA (apnea-hypopnea index, 38 ± 24 events/h on polysomnography) for a mean period of 3.1 years, after switching them to antihypertensive treatment targeting office BP less than 140/90 mmHg (<130/80 mmHg in diabetic patients). Participants were defined as on-CPAP if they adhered to CPAP treatment during the whole follow-up period (N = 41), whereas those that did not follow CPAP therapy served as controls (N = 50). RESULTS: By the end of follow-up, on-CPAP patients and controls exhibited similar SBP and DBP levels (133 ± 12 versus 133 ± 13 mmHg, 84 ± 9 versus 85 ± 9 mmHg, respectively, P > 0.05 for all), number of patients with controlled hypertension (71 versus 70%, P > 0.05), and number of antihypertensive drugs needed to achieve BP control (2.28 ± 1.09 versus 2.11 ± 0.72, P > 0.05). In a subgroup of patients (N = 34) in whom ambulatory BP monitoring was also performed, 24-h BP levels did not differ between the two groups (125 ± 10/76 ± 7 mmHg versus 123 ± 11/75 ± 10 mmHg, P > 0.05). In multiple regression models, CPAP application was not associated with changes in BP levels. CONCLUSION: In nonsleepy, hypertensive, OSA patients on conventional antihypertensive treatment, long-term CPAP application is not associated with lower BP levels or a need for less antihypertensive drugs for BP control.