Nonpharmacologic therapy for hypertension: Does it really work?

Mathematical modeling of antihypertensive therapy

Hypertension is a multifactorial disease arising from complex pathophysiological pathways. Individual characteristics of patients result in different responses to various classes of antihypertensive medications. Therefore, evaluating the efficacy of therapy based on in silico predictions is an important task. This study is a continuation of research on the modular agent-based model of the cardiovascular and renal systems (presented in the previously published article). In the current work, we included in the model equations simulating the response to antihypertensive therapies with different mechanisms of action. For this, we used the pharmacodynamic effects of the angiotensin II receptor blocker losartan, the calcium channel blocker amlodipine, the angiotensin-converting enzyme inhibitor enalapril, the direct renin inhibitor aliskiren, the thiazide diuretic hydrochlorothiazide, and the β-blocker bisoprolol. We fitted therapy parameters based on known clinical trials for all considered medications, and then tested the model's ability to show reasonable dynamics (expected by clinical observations) after treatment with individual drugs and their dual combinations in a group of virtual patients with hypertension. The extended model paves the way for the next step in personalized medicine that is adapting the model parameters to a real patient and predicting his response to antihypertensive therapy. The model is implemented in the BioUML software and is available at https://gitlab.sirius-web.org/virtual-patient/antihypertensive-treatment-modeling.

Meta-Analysis of Randomized Controlled Trials of the Effects of Tai Chi on Blood Pressure

Objectives

The purpose of this study was to investigate the influences of Tai Chi on blood pressure (BP) using the meta-analysis.

Methods

This paper used 6 e-resource databases, and randomized controlled trials on the role of Tai Chi on blood pressure were retrieved. Besides, the meta-analysis was conducted according to the guidelines of the Moose-recommendations and applied with Review Manager 5.3, and the risk of bias assessment was performed with the Cochrane Collaboration's tool. The inclusion, data extraction, and risk of bias assessment were independently finished by two researchers.

Results

There are 24 trials meeting the criteria of inclusion and the results were reviewed. The meta-analysis indicates that, compared with no exercise, Tai Chi had the influence of lowering systolic blood pressure (mean difference = −6.07, 95%CI (−8.75, −3.39), P < 0.00001) and diastolic blood pressure (mean difference MD = −3.83, 95%CI (−4.97, −2.69), P < 0.00001). No significant discrepancies in all outcomes between Tai Chi and other aerobic exercises were discovered.

Conclusion

Tai Chi can significantly reduce systolic and diastolic pressure than inactivity. However, Tai Chi does not show advantages in reducing blood pressure compared to other aerobic exercises. The trial is registered with CRD42020175306.

Efficacy of a behavior change program on cardiovascular parameters in patients with hypertension: a randomized controlled trial

Objective

To investigate the efficacy of a behavior change program named Vida Ativa Melhorando a Saúde on cardiovascular parameters in hypertensive patients.

Methods

Ninety hypertensive patients aged over 40 years were randomly allocated to one of two groups: Vida Ativa Melhorando a Saúde or Control (n=45 respectively). Patients in the Vida Ativa Melhorando a Saúde group took part in a behavior change program aimed to encourage changes in physical activity levels and eating habits, according to the Social Cognitive Theory. The program consisted of 90-minute weekly group meetings conducted by a physical therapist and a dietitian. One chapter of the educational material (workbook) provided was discussed per meeting. Participants in the Control Group attended a single educative lecture on lifestyle changes. Brachial and central blood pressure, arterial stiffness and endothelial function parameters were measured pre- and post-intervention.

Results

Vida Ativa Melhorando a Saúde led to reduction of brachial (131.3±15.8mmHg to 125.1±17.3mmHg; p<0.01) and central (123.6±16.3mmHg to 119.0±20.6mmHg; p=0.02) systolic and brachial diastolic (123.6±16.3mmHg to 119.0±20.6mmHg; p<0.01) blood pressure values, and improvement of post-occlusive reactive hyperemia (from 5.7±2.5mL·100mL⁻¹ to 6.5±2.1mL·100mL⁻¹ tissue·min^−1; p=0.04). No changes in body composition, heart rate and arterial stiffness parameters were detected in both groups (p>0.05).

Conclusion

Vida Ativa Melhorando a Saúde program improved blood pressure and microvascular reactivity in hypertensive patients. Trial registration: ClinicalTrials.gov: NCT02257268

Research protocol: effect of natural S-equol on blood pressure and vascular function--a six-month randomized controlled trial among equol non-producers of postmenopausal women with prehypertension or untreated stage 1 hypertension

BACKGROUND

Although higher habitual soy intake is associated with lower blood pressure (BP) and stroke incidence, clinical trials using soy protein or isoflavones on cardiovascular risks yielded inconsistent results. The discrepancies are hypothesized to be due to the individuals' intestinal bacterial capacity to metabolite isoflavones daidzein into equol. Animal and in vitro studies have revealed that equol has stronger estrogen-like and anti-oxidative activity than isoflavones and possesses natriuretic and vasorelaxant properties which may play an important role in the prevention of hypertension. However, no clinical trial has examined the effect of equol on BP. We thus propose a 24-week randomized controlled trial to test the effectiveness of natural S-equol on BP and vascular function among equol non-producers.

METHODS/DESIGN

This will be a 6-month double-blind, randomized, placebo-controlled trial among 207 non-equol producing postmenopausal women with prehypertension or early untreated hypertension. Eligible participants who have completed a 2-week run-in will be randomized to either one of the 3 groups: placebo group, low-equol group (10 mg/d) and high equol group (20 mg/d). The outcome measures will be conducted at baseline and at the end of the trial including 24 h ambulatory BP, endothelial function (by ultrasound determined brachial flow mediated dilation), arterial stiffness (by pulse wave analysis) and other cardiovascular risk factors (lipid profile, glycemic control and inflammatory biomarkers). Urinary isoflavones will be tested for compliance assessment. One way analysis of variance will be applied to compare the 6-month changes in ambulatory BP or parameters of vascular function among the 3 treatment groups.

DISCUSSION

This study will be performed in community subjects. If the antihypertensive effect of equol is proven, the provision of natural equol to those high risk adults who are unable to produce equol will have enormous public health implications for the primary and secondary prevention of hypertension and cardiovascular diseases on a population basis. The research efforts will also have significant implications for industry in the provision of suitable soy products for the prevention of hypertension and its related complications.

TRIAL REGISTRATION

The trial was registered in ClinicalTrials.gov with identifier of NCT02515682 .

Calcitonin gene-related peptide (CGRP) receptors are important to maintain cerebrovascular reactivity in chronic hypertension

Cerebral blood flow autoregulation (CA) shifts to higher blood pressures in chronic hypertensive patients, which increases their risk for brain damage. Although cerebral vascular smooth muscle cells express the potent vasodilatatory peptides calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) and their receptors (calcitonin receptor-like receptor (Calclr), receptor-modifying proteins (RAMP) 1 and 2), their contribution to CA during chronic hypertension is poorly understood. Here we report that chronic (10 weeks) hypertensive (one-kidney-one-clip-method) mice overexpressing the Calclr in smooth muscle cells (CLR-tg), which increases the natural sensitivity of the brain vasculature to CGRP and AM show significantly better blood pressure drop-induced cerebrovascular reactivity than wt controls. Compared to sham mice, this was paralleled by increased cerebral CGRP-binding sites (receptor autoradiography), significantly in CLR-tg but not wt mice. AM-binding sites remained unchanged. Whereas hypertension did not alter RAMP-1 expression (droplet digital (dd) PCR) in either mouse line, RAMP-2 expression dropped significantly in both mouse lines by about 65%. Moreover, in wt only Calclr expression was reduced by about 70% parallel to an increase of smooth muscle actin (Acta2) expression. Thus, chronic hypertension induces a stoichiometric shift between CGRP and AM receptors in favor of the CGRP receptor. However, the parallel reduction of Calclr expression observed in wt mice but not CLR-tg mice appears to be a key mechanism in chronic hypertension impairing cerebrovascular reactivity.

Rational approaches to the treatment of hypertension: modification of lifestyle measures

Hypertension is an important health problem. Informative counseling is required for patients to completely understand the importance of non-pharmacologic treatments. Lifestyle changes such as restriction of salt intake, exercise, restriction of alcohol intake, diet, and weight loss are included in all hypertension treatment guidelines. However, serious motivation is required from the patient and the physician to succeed in this. Although the decrease in blood pressure may be limited with these measures, lifestyle modifications should be continued.

Effects of disclosing hypothetical genetic test results for salt sensitivity on salt restriction behavior

BACKGROUND

A few studies have explored the effects of disclosure of genetic testing results on chronic disease predisposition. However, these effects remain unclear in cases of hypertension. Reducing salt intake is an important nonpharmacological intervention for hypertension. We investigated the effects of genetic testing for salt sensitivity on salt restriction behavior using hypothetical genetic testing results.

METHODS

We conducted a cross-sectional study using a self-completed questionnaire. We enrolled consecutive outpatients who visited primary care clinics and small hospitals between September and December 2009 in Japan. We recorded the patients' baseline characteristics and data regarding their salt restriction behavior, defined as reducing salt intake before and after disclosure of hypothetical salt sensitivity genetic test results. Behavioral stage was assessed according to the five-stage transtheoretical model. After dividing subjects into salt restriction and no salt restriction groups, we compared their behavioral changes following positive and negative test results and analyzed the association between the respondents' characteristics and their behavioral changes.

RESULTS

We analyzed 1562 participants with a mean age of 58 years. In the no salt restriction group, which included patients at the precontemplation, contemplation, and preparation stages, 58.7% stated that their behavioral stage progressed after a positive test result, although 29.8% reported progression after a negative result (P < 0.001). Conversely, in the salt restriction group, which included patients at the active and maintenance stages, 9.2% stated that they would quit restricting salt intake following a negative test result, and 2.2% reported they would quit following a positive result (P < 0.001). Age < 65 years (adjusted odds ratio [OR] 1.74; 95% confidence interval [CI] 1.12-2.71), female gender (adjusted OR 1.84; CI 1.29-2.62), graduation from college or university (adjusted OR 1.66; CI 1.11-2.49), and desire for genetic testing (adjusted OR 4.53; CI 3.13-6.57) were associated with progression of behavioral stage in the no salt restriction group. Conversely, salt preference (adjusted OR 2.13; CI 1.31-3.49) was associated with quitting salt restriction in the salt restriction group.

CONCLUSION

Patients in the no salt restriction group show the possibility of progression from the behavioral stage to the action stage after testing positive for salt sensitivity. Conversely, patients in the salt restriction group, particularly those with a salt preference, would quit salt restriction after testing negative.

Awareness of hypertension: will it bring about a healthy lifestyle?

Guidelines for cardiovascular disease prevention recommend a non-pharmacological approach to reduce cardiovascular risk in those with elevated blood pressure. We assessed guideline adherence in hypertensives. This study was performed in the European Investigation into Cancer and Nutrition-NL cohort, consisting of 40,011 subjects. From 1993 to 1997, participants completed questionnaires (disease history, lifestyle and diet), a physical examination was performed and blood samples were drawn. Differences in proportions of guideline targets met between aware and unaware hypertensives were studied. Of 8779 hypertensive subjects, 90% was aware of their hypertension. They more often adhered to guidelines than unaware hypertensive subjects with respect to intake of polyunsaturated fat:saturated fat (38.6% vs 33.2%), fibres (40.6% vs 34.2%), body mass index <27 kg m(-2) (53.8% vs 46.5%) and alcohol (79.7% vs 72.6%). Despite statistical significance, the magnitude of these differences was small. Our study suggests that prevalence of a healthy lifestyle according to the recommendations in guidelines is slightly better in subjects aware of hypertension. There seems to be ample room for improvement in implementing the guidelines. Probably, patient tailored interventions and a multisiciplinary and multimodality approach can support this improvement.

Tobacco abuse and physical activity among medical students

Objective

This lifestyle is mainly determined during childhood and connected with poor public prophylactic health policy. The aim of this study was to estimate physical activity and level of tobacco abuse, as well as knowledge about health behaviours, among medical students.

Methods

Questionnaires were completed by Polish (243) and foreign medical students (80).

Results

It was stated that about 20% of the students smoked cigarettes. Female students from Norway took up smoking significantly more often than other participants, whereas there were more smokers among those from Poland. There was a significantly larger percentage of smoking males from Norway than among male Polish students. The same students presented a low level of physical activity. The smallest level of physical activity was characteristic of the Polish women.

Conclusion

This situation requires an intensification of activities aimed at supporting pro-health lifestyles and the elimination of unfavourable effects, especially among medical students.

Tai chi exercise for patients with cardiovascular conditions and risk factors: A SYSTEMATIC REVIEW

PURPOSE

To conduct a systematic review of the literature evaluating tai chi exercise as an intervention for patients with cardiovascular disease (CVD) or with CVD risk factors (CVDRF).

METHODS

We searched (1) MEDLINE, CAB Alt HealthWatch, BIOSIS previews, Science Citation Index, EMBASE, and Social Science Citation Index from inception through October 2007; (2) Chinese Medical Database, China Hospital Knowledge, China National Knowledge Infrastructure, and China Traditional Chinese Medicine Database from inception through June 2005; and (3) the medical libraries of Beijing and Nanjing Universities. Clinical studies published in English and Chinese including participants with established CVD or CVDRF were included. Data were extracted in a standardized manner; 2 independent investigators assessed methodological quality, including the Jadad score for randomized controlled trials (RCTs).

RESULTS

Twenty-nine studies met inclusion criteria: 9 RCTs, 14 nonrandomized studies, and 6 observational trials. Three studies examined subjects with coronary heart disease, 5 in subjects with heart failure, and 10 in heterogeneous populations that included those with CVD. Eleven studies examined subjects with CVDRF (hypertension, dyslipidemia, impaired glucose metabolism). Study duration ranged from 8 weeks to 3 years. Most studies included fewer than 100 subjects (range, 5-207). Six of 9 RCTs were of adequate quality (Jadad >or= 3). Most studies reported improvements with tai chi, including blood pressure reductions and increases in exercise capacity. No adverse effects were reported.

CONCLUSION

Preliminary evidence suggests that tai chi exercise may be a beneficial adjunctive therapy for some patients with CVD and CVDRF. Further research is needed.

Sport therapy for hypertension: why, how, and how much?

Exercise may prevent or reduce the effects of metabolic and cardiovascular diseases, including arterial hypertension. Both acute and chronic exercise, alone or combined with lifestyle modifications, decrease blood pressure and avoid or reduce the need for pharmacologic therapy in patients with hypertension. The hypotensive effect of exercise is observed in a large percentage of subjects, with differences due to age, sex, race, health conditions, parental history, and genetic factors. Exercise regulates autonomic nervous system activity, increases shear stress, improves nitric oxide production in endothelial cells and its bioavailability for vascular smooth muscle, up-regulates antioxidant enzymes. Endurance training is primarily effective, and resistance training can be combined with it. Low-to-moderate intensity training in sedentary patients with hypertension is necessary, and tailored programs make exercise safe and effective also in special populations. Supervised or home-based exercise programs allow a nonpharmacological reduction of hypertension and reduce risk factors, with possible beneficial effects on cardiovascular morbidity.

Cardiovascular Consequences of Obesity and Targets for Treatment

Obesity is a risk factor for cardiovascular disease, including coronary artery disease and heart failure, but the mechanisms by which it may cause them are not completely clear. Currently, therapies aimed at obesity-related cardiovascular disease include weight loss strategies and reduction of the other risk factors that are associated with obesity and cardiovascular disease. Other pathways with for potential drug development for obesity-related CVD are also discussed.

The effect of tai chi exercise on blood pressure: a systematic review

A systematic review of the literature on the effect of tai chi exercise on blood pressure (BP) was performed. The authors searched Medline, CAB, Alt HealthWatch, BIOSIS previews, Science Citation Index, and EMBASE systems (inception through January 2007); researched Chinese Medical, China Hospital Knowledge, China National Knowledge Infrastructure, and China Traditional Chinese Medicine databases (inception to June 2005); and performed hand searches at the medical libraries of Beijing and Nanjing Universities. Clinical studies of tai chi examining BP as an outcome published in English or Chinese were included. Studies reporting only acute exercise effects were excluded. Data were extracted in a standardized manner and 2 independent investigators assessed methodologic quality. Twenty-six studies examining patients with and without cardiovascular conditions met inclusion criteria: 9 randomized controlled trials, 13 nonrandomized studies, and 4 observational studies. Study heterogeneity precluded formal meta-analyses. Twenty-two studies (85%) reported reductions in BP with tai chi (3-32 mm Hg systolic and 2-18 mm Hg diastolic BP reductions). Five randomized controlled trials were of adequate quality (Jadad score > or = 3). No adverse effects were reported. Tai chi exercise may reduce BP and serve as a practical, nonpharmacologic adjunct to conventional hypertension management.

Dangerous exercise: lessons learned from dysregulated inflammatory responses to physical activity

Exercise elicits an immunological “danger” type of stress and inflammatory response that, on occasion, becomes dysregulated and detrimental to health. Examples include anaphylaxis, exercise-induced asthma, overuse syndromes, and exacerbation of intercurrent illnesses. In dangerous exercise, the normal balance between pro- and anti-inflammatory responses is upset. A possible pathophysiological mechanism is characterized by the concept of exercise modulation of previously activated leukocytes. In this model, circulating leukocytes are rendered more responsive than normal to the immune stimulus of exercise. For example, in the case of exercise anaphylaxis, food-sensitized immune cells may be relatively innocuous until they are redistributed during exercise from gut-associated circulatory depots, like the spleen, into the central circulation. In the case of asthma, the prior activation of leukocytes may be the result of genetic or environmental factors. In the case of overuse syndromes, the normally short-lived neutrophil may, because of acidosis and hypoxia, inhibit apoptosis and play a role in prolongation of inflammation rather than healing. Dangerous exercise demonstrates that the stress/inflammatory response caused by physical activity is robust and sufficiently powerful, perhaps, to alter subsequent responses. These longer term effects may occur through as yet unexplored mechanisms of immune “tolerance” and/or by a training-associated reduction in the innate immune response to brief exercise. A better understanding of sometimes failed homeostatic physiological systems can lead to new insights with significant implication for clinical translation.