Essential hypertension is associated with blunted smooth muscle cell vasodilator responsiveness and is reversed by 10-20-30 training in men

10-20-30 exercise training improves fitness and health

Intense interval exercise training has been shown to improve performance and health of untrained and trained people. However, due to the exercise intensity causing high-perceived exertion, the participants often do not wish to continue the training. The 10-20-30 training concept consists of low intensity for 30 s, 20 s at a moderate pace, and then 10 s with high intensity either running or cycling. A 10-20-30 training session consist of two to four 5-min blocks. The 10-20-30 training improved fitness and performance as well as lowered blood pressure and body fat of both untrained and trained individuals even with a significant reduction in the training volume. Similarly, hypertensive, diabetic, and asthmatic patients lowered body fat, improved fitness, and performance during a 10-20-30-training intervention period. In addition, hypertensive patients reduced systolic and diastolic blood pressure markedly with the 10-20-30 training twice a week for 8 weeks. Diabetic patients lowered long-term blood sugar (HbA1c), which did not occur with moderate-intensity exercise training. Furthermore, asthmatic patients improved their control of asthma and asthma-related quality of life with the 10-20-30 training. The adherence for the patient groups was high (>80%), and no adverse events were reported. Thus, the 10-20-30 training seems to be time efficient and feasible for untrained and trained individuals as well as patients and may be used in the prevention and treatment of noncommunicable diseases.

The PAD-adapted 30-20-10 during Nordic walking: A new exercise training session in patients with symptomatic peripheral artery disease

This study aimed to investigate the feasibility of a peripheral artery disease (PAD)-adapted 30-20-10 Nordic walking session in patients with symptomatic PAD and to compare the cardiovascular response of this new training session to a traditional walking (TW) and 4 × 4 minutes Nordic walking session. This is a prospective observational study. Patients with Fontaine stage II PAD were included. Patients participated in Nordic walking sessions, which were randomly assigned as TW, 4 × 4 minute intervals, and peripheral artery disease adapted 30-20-10 exercise session (PAD-adapted 30-20-10 sessions). PAD-adapted 30-20-10 and 4 × 4 minutes sessions consisted of 4 repetitions of 4 minutes of effort followed by 3 minutes of passive recovery. PAD-adapted 30-20-10 session was characterized by 4 continuous 1-min repetitions at 3 different walking speeds [high (30 seconds), moderate (20 seconds) and low (10 seconds)]. During the 4 × 4 minutes session, patients were asked to cover the maximal distance at a constant speed. During TW session, patients were asked to walk at a speed inducing moderate-to-severe claudication pain. Heart rate, rating of perceived exertion (RPE) and claudication pain intensity using a visual analog scale were assessed. The perceived enjoyment of each session was assessed using a visual analog scale ranging from 0 (not enjoyable) to 10 (very enjoyable). Eleven patients with chronic symptomatic PAD were included (62 ± 13 years; 54% women). The mean heart rate during the time of effort was significantly higher in PAD-adapted 30-20-10 group than in 4 × 4 minutes and TW groups (127 ± 12, 122 ± 12, 114 ± 11 bpm, respectively; P ≤ .001). The mean rating of perceived exertion (16 ± 1, 15 ± 1, 13 ± 1; P ≤ .001) and claudication pain intensity (8 ± 1, 7 ± 1; 7 ± 1 mm; P ≤ .019) were significantly higher during PAD-adapted 30-20-10 sessions than during 4 × 4 minutes and TW sessions. The perceived enjoyment was similar among sessions (8.7 ± 1.6 for TW, 8.6 ± 1.7 for 4 × 4 minutes, and 8.8 ± 1.8 mm for PAD-adapted 30-20-10 sessions; P = .935). The PAD-adapted 30-20-10 session is feasible and induces higher cardiovascular stimulation and claudication pain than 4 × 4 minutes and TW procedures in patients with symptomatic PAD. Despite these different responses, a similar perceived enjoyment among the sessions has been shown. Future investigations are needed to examine the effects of this new training session in these patients.

The cardiovascular changes underlying a low cardiac output with exercise in patients with type 2 diabetes mellitus

The significant morbidity and premature mortality of type 2 diabetes mellitus (T2DM) is largely associated with its cardiovascular consequences. Focus has long been on the arterial atheromatosis of DM giving rise to early stroke and myocardial infarctions, whereas less attention has been given to its non-ischemic cardiovascular consequences. Irrespective of ischemic changes, T2DM is associated with heart failure (HF) most commonly with preserved ejection fraction (HFpEF). Largely due to increasing population ages, hypertension, obesity and T2DM, HFpEF is becoming the most prevalent form of heart failure. Unfortunately, randomized controlled trials of HFpEF have largely been futile, and it now seems logical to address the important different phenotypes of HFpEF to understand their underlying pathophysiology. In the early phases, HFpEF is associated with a significantly impaired ability to increase cardiac output with exercise. The lowered cardiac output with exercise results from both cardiac and peripheral causes. T2DM is associated with left ventricular (LV) diastolic dysfunction based on LV hypertrophy with myocardial disperse fibrosis and significantly impaired ability for myocardial blood flow increments with exercise. T2DM is also associated with impaired ability for skeletal muscle vasodilation during exercise, and as is the case in the myocardium, such changes may be related to vascular rarefaction. The present review discusses the underlying phenotypical changes of the heart and peripheral vascular system and their importance for an adequate increase in cardiac output. Since many of the described cardiovascular changes with T2DM must be considered difficult to change if fully developed, it is suggested that patients with T2DM are early evaluated with respect to their cardiovascular compromise.

Is the Pannexin-1 Channel a Mechanism Underlying Hypertension in Humans? a Translational Study of Human Hypertension

BACKGROUND

In preclinical models, the pannexin-1 channel has been shown to be involved in blood pressure regulation through an effect on peripheral vascular resistance. Pannexin-1 releases ATP, which can activate constrictive purinergic receptors on the smooth muscle cells. Pannexin-1 opening is proposed to be mediated by α-adrenergic receptors to potentiate sympathetic constriction. This positions pannexin-1 as a putative pharmacological target in blood pressure regulation in humans. The aim was to provide the first translational evidence for a role of pannexin-1 in essential hypertension in humans by use of an advanced invasive mechanistic approach.

METHODS

Middle-aged stage-1 hypertensive (n=13; 135.7±6.4 over 83.7±3.7 mm Hg) and normotensive men (n=12; 117.3±5.7 over 72.2±3.5 mm Hg) were included. Blood pressure and leg vascular resistance were determined during femoral arterial infusion of tyramine (α-adrenergic receptor stimulation), sodium nitroprusside, and acetylcholine. Measurements were made during control conditions and with pannexin-1 blockade (3000 mg probenecid). Expression of purinergic- and α-adrenergic receptors in skeletal muscle biopsies was determined by Western blot.

RESULTS

The changes in leg vascular resistance in response to tyramine (+289% versus +222%), sodium nitroprusside (-82% versus -78%) and acetylcholine (-40% versus -44%) infusion were not different between the 2 groups (P>0.05) and pannexin-1 blockade did not alter these variables (P>0.05). Expression of pannexin-1 and of purinergic- and α-adrenergic receptors was not different between the 2 groups (P>0.05).

CONCLUSIONS

Contrary to our hypothesis, the data demonstrate that pannexin-1 does not contribute to the elevated blood pressure in essential hypertension, a finding, which also opposes that reported in preclinical models.

Upregulation of miR-140-5p uncouples mitochondria by targeting Bcl-xL in vascular smooth muscle cells in angiotensin II-induced hypertension

Angiotensin II–induced vascular smooth muscle cell (VSMC) remodeling and dysfunction is a major contributor to the development of hypertension. In spite of the low content of mitochondria and their low contribution to bioenergetics in VSMCs, recent studies have suggested that mitochondria play an important role in the regulation of VSMC function. However, the role of mitochondria in angiotensin II–induced VSMC dysfunction remains unknown. Here, we found that angiotensin II decreased the expression of Bcl-2-like protein 1 (Bcl-xL), a newly identified protein in inhibition of uncoupled proton flux in mitochondria through interaction with the β-subunit of ATP synthase, and uncoupled mitochondria in VSMCs both in vivo and in vitro. Overexpression of Bcl-xL restored the mitochondrial and VSMC function in response to angiotensin II treatment in vitro, suggesting that angiotensin II uncouples mitochondria through downregulation of Bcl-xL. Mechanistically, angiotensin II increased the expression of miR-140-5p, which targeted and downregulated Bcl-xL in VSMCs. Inhibition of miR-140-5p using antagomir-140-5p in vivo attenuated mitochondrial uncoupling and hypertension in angiotensin II-treated mice. These results suggested that upregulation of miR-140-5p uncouples mitochondria by targeting Bcl-xL in VSMCs in angiotensin II–induced hypertension, and miR-140-5p and Bcl-xL are potential targets for treatment of vascular dysfunction.

Antihypertensive Effects of the Methanol Extract and the Ethyl Acetate Fraction from Crinum zeylanicum (Amaryllidaceae) Leaves in L-NAME-Treated Rat

Arterial hypertension (AHT) is a leading cardiovascular disease, with a high negative impact on the quality of life. Crinum zeylanicum (C. zeylanicum) leaves extract is used in the West region of Cameroon to treat AHT and heart problems. This study aimed to investigate the antihypertensive effect of C. zeylanicum extract in N^ω-nitro-L‐arginine methyl ester- (L‐NAME-) induced hypertensive rats. The aqueous extract of C. zeylanicum (LAE) was obtained by lyophilizing the juice of triturated fresh leaves. The methanol extract (LME) prepared by maceration of the dried leaves was further partitioned to chloroform (LCF), ethyl acetate (LEAF), and residual (LRF) fractions. The total polyphenol, flavonoid content, and antiradical potentials of these extracts were determined. The curative antihypertensive and renal function protective effects of LME and LEAF were evaluated in vivo on L-NAME-induced hypertensive rats. Hypertension was induced in rats by oral administration of L-NAME (30 mg/kg/day) for 3 consecutive weeks. Thereafter, plant extracts were administered orally at the doses of 30, 60, and 120 mg/kg/day, concomitantly with L-NAME for three other weeks. Body weight, heart rate, and arterial blood pressure were measured at the end of each week throughout the experimental period. At the end of the treatment, 24-hour urine and plasma were collected to assay nitric oxide (NO), creatinine, and protein. The results revealed that LEAF has the higher content of total polyphenol and flavonoid and exhibited the best antiradical potential. Moreover, treatment of hypertensive rats with LME and LEAF significantly (p < 0.001) reduced AHT and heart rate. LME and LEAF significantly increased rat's body mass, plasmatic NO, and urinary creatinine and reduced urine NO and protein contents as compared to the L-NAME group. LME and its LEAF possess potent antihypertensive effects and further protect the renal function in L-NAME-induced hypertensive rats, thus supporting the use of C. zeylanicum in the management of AHT.

Does exercise training improve the function of vascular smooth muscle? A systematic review and meta-analysis

We aimed to determine the effects of exercise training on the function of vascular smooth muscle cells. PubMed and Web of Science about the effects of exercise training on vascular smooth muscle cells were searched up to August 2020. The effect sizes were estimated in terms of the standardized mean difference. The number of studies included was thirty-five overall. Exercise training had positive effects on vascular smooth muscle cells function in participants older than 40. Effect sizes for HIGH intensity and MIX were positive but small, and also when training duration was longer than 12 weeks. We concluded that vascular smooth muscle cells response can be promoted by exercise training. Vigorous aerobic exercise and mixture training modality were the best ways to promote the dilation response of vascular smooth muscle cells. Additionally, the significant improvement induced by exercise training only occurred when training lasted for longer than 12 weeks.

Hypertension is associated with blunted NO-mediated leg vasodilator responsiveness that is reversed by high-intensity training in postmenopausal women

The menopausal transition is associated with increased prevalence of hypertension, and in time, postmenopausal women (PMW) will exhibit a cardiovascular disease risk score similar to male counterparts. Hypertension is associated with vascular dysfunction, but whether hypertensive (HYP) PMW have blunted nitric oxide (NO)-mediated leg vasodilator responsiveness and whether this is reversible by high-intensity training (HIT) is unknown. To address these questions, we examined the leg vascular conductance (LVC) in response to femoral infusion of acetylcholine (ACh) and sodium nitroprusside (SNP) and skeletal muscle markers of oxidative stress and NO bioavailability before and after HIT in PMW [12.9 ± 6.0 (means ± SD) years since last menstrual cycle]. We hypothesized that ACh- and SNP-induced LVC responsiveness was reduced in hypertensive compared with normotensive (NORM) PMW and that 10 wk of HIT would reverse the blunted LVC response and decrease blood pressure (BP). Nine hypertensive (HYP (clinical systolic/diastolic BP, 149 ± 11/91 ± 83 mmHg) and eight normotensive (NORM (122 ± 13/75 ± 8 mmHg) PMW completed 10 wk of biweekly small-sided floorball training (4-5 × 3-5 min interspersed by 1-3-min rest periods). Before training, the SNP-induced change in LVC was lower (P < 0.05) in HYP compared with in NORM. With training, the ACh- and SNP-induced change in LVC at maximal infusion rates, i.e., 100 and 6 µg·min^-1·kg leg mass^-1, respectively, improved (P < 0.05) in HYP only. Furthermore, training decreased (P < 0.05) clinical systolic/diastolic BP (-15 ± 11/-9 ± 7 mmHg) in HYP and systolic BP (-10 ± 9 mmHg) in NORM. Thus, the SNP-mediated LVC responsiveness was blunted in HYP PMW and reversed by a period of HIT that was associated with a marked decrease in clinical BP.

High-Intensity Interval Training Decreases Muscle Sympathetic Nerve Activity in Men With Essential Hypertension and in Normotensive Controls

Exercise training is a cornerstone in reducing blood pressure (BP) and muscle sympathetic nerve activity (MSNA) in individuals with essential hypertension. High-intensity interval training (HIIT) has been shown to be a time efficient alternative to classical continuous training in lowering BP in essential hypertension, but the effect of HIIT on MSNA levels has never been investigated. Leg MSNA responsiveness to 6 weeks of HIIT was examined in 14 hypertensive men (HYP; age: 62 ± 7 years, night time BP: 136 ± 12/83 ± 8 mmHg, BMI: 28 ± 3 kg/m²), and 10 age-matched normotensive controls (NORM; age: 60 ± 8 years, night time BP: 116 ± 2/68 ± 4 mmHg and BMI: 27 ± 3 kg/m²). Before training, MSNA levels were not different between HYP and NORM (burst frequency (BF): 41.0 ± 10.3 vs. 33.6 ± 10.6 bursts/min and burst incidence (BI): 67.5 ± 19.7 vs. 64.2 ± 17.0 bursts/100 heart beats, respectively). BF decreased (P < 0.05) with training by 13 and 5% in HYP and NORM, respectively, whereas BI decreased by 7% in NORM only, with no difference between groups. Training lowered (P < 0.05) night-time mean arterial- and diastolic BP in HYP only (100 ± 8 vs. 97 ± 5, and 82 ± 6 vs. 79 ± 5 mmHg, respectively). The change in HYP was greater (P < 0.05) compared to NORM. Training reduced (P < 0.05) body mass, visceral fat mass, and fat percentage similarly within- and between groups, with no change in fat free mass. Training increased (P < 0.05) V̇O₂-max in NORM only. Six weeks of HIIT lowered resting MSNA levels in age-matched hyper- and normotensive men, which was paralleled by a significant reduction in BP in the hypertensive men.

Increased prostacyclin formation after high-intensity interval training in late postmenopausal women

PURPOSE

Aging impairs vascular function in women, with the largest detrimental effects occurring during the menopausal transition. Deficiency in the nitric oxide system has been suggested to be responsible for impairment in vascular function with aging, but recent observations suggest that the prostacyclin system, acting in redundancy with the nitric oxide system, may be of importance too. Improvement in vascular function is a hallmark of exercise training and we hypothesize that leg vascular function is improved by exercise training in late postmenopausal women, and that the underlying mechanism is increased endothelial formation of prostacyclin and responsiveness to prostacyclin by the vascular smooth muscle cells.

METHOD

Femoral-arterial infusion of acetylcholine and epoprostenol was used to assess vascular function and prostacyclin release in ten late postmenopausal women (62 ± 7 years) before and after 10 weeks of high-intensity interval training (floorball conducted as small-sided games).

RESULT

The training intervention increased fitness level (V̇O2max) by 7 ± 7% and reduced systolic and diastolic blood pressure by 10 ± 10 and 5 ± 6 mmHg, respectively. Leg vascular responsiveness to during acetylcholine and epoprostenol infusion was unchanged with training, whereas the release of prostacyclin during acetylcholine infusion increased by 125%.

CONCLUSIONS

In late postmenopausal women, vascular function assessed by femoral-arterial infusion of acetylcholine was not improved after 10 weeks of floorball training, but acetylcholine-induced prostacyclin formation and blood pressure were substantially improved. It is possible that a longer training period could lead to improvements in vascular function and that the observed increase in prostacyclin formation is one of the initial underlying changes.