Exercise as hypertension therapy

Lowering blood pressure by exercise: investigating the effect of sweating

High blood pressure (hypertension), is a common medical condition, affecting millions of people and is associated with significant health risks. Exercise has been suggested to manage hypertension by inducing sweating and the corresponding loss of sodium and water from the body.Thus, a variety of epidemiological and clinical studies have been conducted to investigate the relationship between sweating and exercise-induced blood pressure reduction and its impacts on hypertension. The mechanisms underlying exercise-induced blood pressure reduction are complex and still not fully understood. However, several pathways have been suggested, including the loss of sodium and water through sweat, a decrease in peripheral resistance, and an improvement in endothelial function in the blood vessels. The decrease in sodium and water content in the body associated with sweating may result in a reduction in blood volume and thus a decrease in blood pressure. Moreover, the reduction in peripheral resistance is thought to be mediated by the activation of the nitric oxide synthase pathway and the release of vasodilators such as prostacyclin and bradykinin, which lead to vasodilation and, thus, a reduction in blood pressure. In conclusion, exercise-induced sweating and consequent sodium and water loss appear to be a reliable biological link to the blood pressure-reducing effects of exercise in hypertensive individuals. Additionally, the mechanisms underlying exercise-induced blood pressure reduction are complex and involve several biological pathways in the cardiovascular system. Therefore, understanding the role of sweat production in blood pressure management is important for developing effective exercise interventions to prevent and manage hypertension.

The Moderated Mediation Effect of Age and Relaxation on the Relationship between the Type A Behavior Pattern and Blood Pressure in South Korea

Although it is generally known that the type A behavior pattern (TABP) is associated with high blood pressure, recent studies have not consistently supported this association. Therefore, it is important to determine which factors moderate and mediate this relationship. The purpose of this study was to verify the moderated mediation effect of age and relaxation in the relationship between TABP and high blood pressure among middle-aged adults in South Korea. This study utilized data from the Korea Health and Genome Study (KHGS) supported by the Korea National Institute of Health. The participants in the present study were 10,022 Korean adults aged 40 to 69. To identify the conditional indirect effect of TABP on blood pressure through relaxation, with a consideration of age, a moderated mediation model using SPSS PROCESS macro 3.10 was applied. As is generally known, TABP was associated with high blood pressure, but its relevance was reversed through relaxation. Moreover, this relationship was moderated by age, which is known to be the most powerful predictor of high blood pressure. The lower age group with TABP exhibited a higher relaxation, whereas the higher age group with TABP demonstrated a lower relaxation. The findings demonstrate the need for relaxation education, stress management, or counseling to help individuals recognize their behavior patterns and strengthen the willingness and motivation for relaxation, especially among elderly people with TABP, in order to manage their blood pressure effectively.

Exaggerated renal sympathetic nerve and pressor responses during spontaneously occurring motor activity in hypertensive rats

Stimulation of the mesencephalic locomotor region elicits exaggerated sympathetic nerve and pressor responses in spontaneously hypertensive rats (SHR) as compared with normotensive Wistar-Kyoto rats (WKY). This suggests that central command or its influence on vasomotor centers is augmented in hypertension. The decerebrate animal model possesses an ability to evoke intermittent bouts of spontaneously occurring motor activity (SpMA) and generates cardiovascular responses associated with the SpMA. It remains unknown whether the changes in sympathetic nerve activity and hemodynamics during SpMA are altered by hypertension. To test the hypothesis that the responses in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) during SpMA are exaggerated with hypertension, this study aimed to compare the responses in decerebrate, paralyzed SHR, WKY, and normotensive Sprague-Dawley (SD) rats. In all strains, an abrupt increase in RSNA occurred in synchronization with tibial motor discharge (an index of motor activity) and was followed by rises in MAP and heart rate. The centrally evoked increase in RSNA and MAP during SpMA was much greater (306 ± 110%) in SHR than WKY (187 ± 146%) and SD (165 ± 44%). Although resting baroreflex-mediated changes in RSNA were not different across strains, mechanically or pharmacologically induced elevations in MAP attenuated or abolished the RSNA increase during SpMA in WKY and SD but had no effect in SHR. It is likely that the exaggerated sympathetic nerve and pressor responses during SpMA in SHR are induced along a central command pathway independent of the arterial baroreflex and/or result from central command-induced inhibition of the baroreflex.

Exercise-Induced Changes in Bioactive Lipids Might Serve as Potential Predictors of Post-Exercise Hypotension. A Pilot Study in Healthy Volunteers

Post-exercise hypotension (PEH) is the phenomenon of lowered blood pressure after a single bout of exercise. Only a fraction of people develops PEH but its occurrence correlates well with long-term effects of sports on blood pressure. Therefore, PEH has been suggested as a suitable predictor for the effectivity of exercise as therapy in hypertension. Local vascular bioactive lipids might play a potential role in this context. We performed a cross-over clinical pilot study with 18 healthy volunteers to investigate the occurrence of PEH after a single short-term endurance exercise. Furthermore, we investigated the plasma lipid profile with focus on arachidonic acid (AA)-derived metabolites as potential biomarkers of PEH. A single bout of ergometer cycling induced a significant PEH in healthy volunteers with the expected high inter-individual variability. Targeted lipid spectrum analysis revealed significant upregulation of several lipids in the direct post-exercise phase. Among these changes, only 15- hydroxyeicosatetranoic acid (HETE) correlated significantly with the extent of PEH but in an AA-independent manner, suggesting that 15-HETE might act as specific PEH-marker. Our data indicate that specific lipid modulation might facilitate the identification of patients who will benefit from exercise activity in hypertension therapy. However, larger trials including hypertonic patients are necessary to verify the clinical value of this hypothesis.

Cardiorespiratory fitness diminishes the effects of age on white matter hyperintensity volume

White matter hyperintensities (WMHs) are among the most commonly observed marker of cerebrovascular disease. Age is a key risk factor for WMH development. Cardiorespiratory fitness (CRF) is associated with increased vessel compliance, but it remains unknown if high CRF affects WMH volume. This study explored the effects of CRF on WMH volume in community-dwelling older adults. We further tested the possibility of an interaction between CRF and age on WMH volume. Participants were 76 adults between the ages of 59 and 77 (mean age = 65.36 years, SD = 3.92) who underwent a maximal graded exercise test and structural brain imaging. Results indicated that age was a predictor of WMH volume (beta = .32, p = .015). However, an age-by-CRF interaction was observed such that higher CRF was associated with lower WMH volume in older participants (beta = -.25, p = .040). Our findings suggest that higher levels of aerobic fitness may protect cerebrovascular health in older adults.

Improved Calcium Homeostasis and Force by Selenium Treatment and Training in Aged Mouse Skeletal Muscle

During aging reduction in muscle mass (sarcopenia) and decrease in physical activity lead to partial loss of muscle force and increased fatigability. Deficiency in the essential trace element selenium might augment these symptoms as it can cause muscle pain, fatigue, and proximal weakness. Average voluntary daily running, maximal twitch and tetanic force, and calcium release from the sarcoplasmic reticulum (SR) decreased while reactive oxygen species (ROS) production associated with tetanic contractions increased in aged – 22-month-old – as compared to young – 4-month-old – mice. These changes were accompanied by a decline in the ryanodine receptor type 1 (RyR1) and Selenoprotein N content and the increased amount of a degraded RyR1. Both lifelong training and selenium supplementation, but not the presence of an increased muscle mass at young age, were able to compensate for the reduction in muscle force and SR calcium release with age. Selenium supplementation was also able to significantly enhance the Selenoprotein N levels in aged mice. Our results describe, for the first time, the beneficial effects of selenium supplementation on calcium release from the SR and muscle force in old age while point out that increased muscle mass does not improve physical performance with aging.

Developing a Physical Activity Ontology to Support the Interoperability of Physical Activity Data

Background

Physical activity data provides important information on disease onset, progression, and treatment outcomes. Although analyzing physical activity data in conjunction with other clinical and microbiological data will lead to new insights crucial for improving human health, it has been hampered partly because of the large variations in the way the data are collected and presented.

Objective

The aim of this study was to develop a Physical Activity Ontology (PACO) to support structuring and standardizing heterogeneous descriptions of physical activities.

Methods

We prepared a corpus of 1140 unique sentences collected from various physical activity questionnaires and scales as well as existing standardized terminologies and ontologies. We extracted concepts relevant to physical activity from the corpus using a natural language processing toolkit called Multipurpose Text Processing Tool. The target concepts were formalized into an ontology using Protégé (version 4). Evaluation of PACO was performed to ensure logical and structural consistency as well as adherence to the best practice principles of building an ontology. A use case application of PACO was demonstrated by structuring and standardizing 36 exercise habit statements and then automatically classifying them to a defined class of either sufficiently active or insufficiently active using FaCT++, an ontology reasoner available in Protégé.

Results

PACO was constructed using 268 unique concepts extracted from the questionnaires and assessment scales. PACO contains 225 classes including 9 defined classes, 20 object properties, 1 data property, and 23 instances (excluding 36 exercise statements). The maximum depth of classes is 4, and the maximum number of siblings is 38. The evaluations with ontology auditing tools confirmed that PACO is structurally and logically consistent and satisfies the majority of the best practice rules of ontology authoring. We showed in a small sample of 36 exercise habit statements that we could formally represent them using PACO concepts and object properties. The formal representation was used to infer a patient activity status category of sufficiently active or insufficiently active using the FaCT++ reasoner.

Conclusions

As a first step toward standardizing and structuring heterogeneous descriptions of physical activities for integrative data analyses, PACO was constructed based on the concepts collected from physical activity questionnaires and assessment scales. PACO was evaluated to be structurally consistent and compliant to ontology authoring principles. PACO was also demonstrated to be potentially useful in standardizing heterogeneous physical activity descriptions and classifying them into clinically meaningful categories that reflect adequacy of exercise.

Relation of Postexercise Reduction of Arterial Blood Pressure and Erectile Dysfunction in Patients with Coronary Heart Disease

Penile erection is a hemodynamic process consisting of 2 synchronized components in which the first (active) requires proper vascular endothelium functioning, whereas the second one (passive) is based on a veno-occlusive mechanism. Antihypertensive treatment reduces the passive component, often leading to the development of erectile dysfunction (ED), but lifestyle modifications can improve the sexual functioning. The study aimed to evaluate the association between blood pressure (BP) reduction caused by cardiovascular training and the intensity of ED in men with coronary heart disease. A total of 101 men (mean age 59.50 ± 7.93) with ED treated invasively for coronary heart disease and subjected to cardiac rehabilitation were enrolled. Patient characteristics, the International Index of Erectile Function 5 (IIEF-5) questionnaire (IIEF-5), and BP values were collected at baseline and after 6 months of cardiac rehabilitation and were analyzed. Cardiac rehabilitation led to a significant reduction of 5.08 mm Hg in systolic BP (p <0.001) and of 1.60 mm Hg in diastolic BP (p <0.001). The IIEF-5 score (EQ) significantly increased (median 15, interquartile range 11 to 19 vs median 18, interquartile range 12 to 21, p <0.001). Greater improvement in sexual performance was significantly negatively correlated with age, concentration of triglycerides, and high-density lipoprotein, whereas it was positively correlated with the presence of diabetes and baseline IIEF-5 score. After excluding patients with diabetes, a greater decrease in systolic BP was found to be significantly associated with greater improvement in erectile performance. In conclusion, a reduction of arterial BP caused by cardiac training is accompanied by improvement in erectile performance. This effect is the strongest in patients with hypertension and those with dyslipidemia.

Association of baseline level of physical activity and its temporal changes with incident hypertension and diabetes mellitus

Background The association between baseline and temporal changes in physical activity and incident hypertension or diabetes mellitus in initially non-hypertensive or non-diabetic subjects is rarely known. Methods Among individuals who underwent consecutive comprehensive health screenings, their physical activity level was measured using a self-reported international physical activity questionnaire. First, subjects were classified into four categories: no regular physical activity with a sedentary lifestyle; minimal physical activity (<75 min/week); insufficient physical activity (≥75 min but <150 min/week); and sufficient physical activity (≥150 min/week). Second, subjects were sub-grouped, based on temporal changes in physical activity level between baseline and consecutive follow-up: increase, no change, and decrease. Results Finally, among 174,314 subjects (mean age 36.7 ± 6.9 years), 5544 (3.18%) and 21,276 (12.2%) developed incident diabetes mellitus and arterial hypertension, respectively. After a multivariate adjustment, sufficient baseline physical activity was associated with significantly lower risk for incident hypertension (hazard ratio 0.89; 95% confidence interval (CI) 0.81 to 0.97), but the difference was not significant, and showed a lower trend in diabetes mellitus incidence (hazard ratio 0.87; 95% CI 0.69 to 1.04) in reference to no regular physical activity group. Regardless of the baseline physical activity level, subjects with a temporal increase in physical activity showed significantly decreased risk for incident hypertension (hazard ratio 0.93; 95% CI 0.87 to 0.99) and diabetes mellitus (hazard ratio 0.83; 95% CI 0.74 to 0.92) compared with those with a temporal decrease in their physical activity level. Conclusion Both sufficient baseline physical activity level and its temporal increase were associated with a lower risk of incident hypertension and diabetes mellitus in a large, relatively healthy, cohort.

Older Women with Controlled Isolated Systolic Hypertension: Exercise and Blood Pressure

INTRODUCTION

Exercise is generally regarded as beneficial for health, but the consequent increases in blood pressure might pose a risk for hypertensive subjects. The purpose of this study was to determine blood pressure responses to dynamic exercise and sustained handgrip in patients with isolated systolic hypertension (ISH) who were stable on medication.

METHODS

Nineteen female ISH patients (66 ± 5 yr) and 19 age-matched normotensive (NT) female controls undertook a 5-min cycle exercise (60% heart rate reserve [HRR]) and a 2-min handgrip exercise (30% maximum voluntary contraction). Blood pressure responses were measured using an oscillometric cuff, together with heart rate and resting brachial pulse transit times.

RESULTS

Systolic blood pressure (SBP) levels after cycle exercise were 194 ± 18 and 153 ± 19 mm Hg for ISH and NT, respectively, with the increase above resting being greater for ISH (P < 0.001), and only small changes were found in diastolic blood pressure (DBP). During handgrip exercise, SBP rose to 168 ± 19 and 140 ± 8 mm Hg for ISH and NT, respectively. The increases above baseline were greater for ISH both during the exercise and postexercise circulatory occlusion (P = 0.017). The increase in DBP levels during exercise and postexercise occlusion were similar in ISH and NT, suggesting little difference in metaboreflex sensitivity. Pulse transit time was shorter for ISH compared with NT (166 ± 6 ms and 242 ± 24 ms, respectively, P < 0.001), indicating stiffer arteries, which would increase SBP but not DBP.

CONCLUSION

Despite being well controlled and normotensive control subjects at rest, ISH patients had high SBP responses to both dynamic and static exercises, which may constitute a risk for cardiovascular incidents.

Moderate Treadmill Exercise Training Improves Cardiovascular and Nitrergic Response and Resistance to Trypanosoma cruzi Infection in Mice

There is evidence suggesting that exercise training (ET) acts as a factor toward resistance to Trypanosoma cruzi infection. However, the effects of mean arterial pressure (MAP), heart rate (HR), and nitric oxide (NO) during the acute phase of infection has not been elucidated yet. Swiss mice were randomly assigned into four groups: sedentary control (SC, n = 30), trained control (TC, n = 30), sedentary infected (SI, n = 30), and trained infected (TI, n = 30). ET was performed on the treadmill for 9 weeks. After training, the mice were infected with 5 × 10³ trypomastigotes of T. cruzi (Y strain) or PBS. We observed resting bradycardia and improved performance in trained animals compared with sedentary ones. On the 20th day post-infection (DPI), we found a decrease in HR in SI animals compared to TI animals (699.73 ± 42.37 vs. 742.11 ± 25.35 bpm, respectively, P < 0.05). We also observed increased production of NO in cardiac tissue on the 20th DPI in the SI group, normalized in TI group (20.73 ± 2.74 vs. 6.51 ± 1.19 μM, respectively). Plasma pro-inflammatory cytokines (IL-12, TNF-α, IFN-γ,) and MCP-1 were increased in SI animals, but decreased in TI animals. The increase in parasitemia on the 15th and 17th DPI in the SI group was attenuated in the TI group. Our results suggest that previous ET plays a preventive role in resistance to T. cruzi infection, modulating cardiovascular aspects, inflammatory reaction, and NO levels of infected mice.

Assessing Physical Activity Levels in Filipino Americans With Hypertension Using the Rapid Assessment of Physical Activity Questionnaire

Regular physical activity decreases the risk of cardiovascular disease and premature death. Little research has been conducted among Filipino Americans about their level of physical activity. Using the validated Rapid Assessment of Physical Activity questionnaire, we examined the activity level of Filipino Americans ( N = 108) from the southwest region of the United States and compared the findings with national physical activity guidelines. The sample mean age was 65 years, 98% were born in the Philippines, 31% had some college education, 71% were married, and 40% had incomes less than $25,000. The mean blood pressure was 140/85 mmHg. The mean score for physical activity level was 5 (max. score 7) and for strength and flexibility 1 (max. score 3), which is less than the recommended guidelines. Lifestyle strategies to increase physical activity and reduce obesity and hypertension in this high-risk, understudied population are warranted.

Altered Blood Flow Response to Small Muscle Mass Exercise in Cancer Survivors Treated With Adjuvant Therapy

Background

Adjuvant cancer treatments have been shown to decrease cardiac function. In addition to changes in cardiovascular risk, there are several additional functional consequences including decreases in exercise capacity and increased incidence of cancer‐related fatigue. However, the effects of adjuvant cancer treatment on peripheral vascular function during exercise in cancer survivors have not been well documented. We investigated the vascular responses to exercise in cancer survivors previously treated with adjuvant cancer therapies.

Methods and Results

Peripheral vascular responses were investigated in 11 cancer survivors previously treated with adjuvant cancer therapies (age 58±6 years, 34±30 months from diagnosis) and 9 healthy controls group matched for age, sex, and maximal voluntary contraction. A dynamic handgrip exercise test at 20% maximal voluntary contraction was performed with simultaneous measurements of forearm blood flow and mean arterial pressure. Forearm vascular conductance was calculated from forearm blood flow and mean arterial pressure. Left ventricular ejection time index (LVETi) was derived from the arterial pressure wave form. Forearm blood flow was attenuated in cancer therapies compared to control at 20% maximal voluntary contraction (189.8±53.8 vs 247.9±80.3 mL·min⁻¹, respectively). Forearm vascular conductance was not different between groups at rest or during exercise. Mean arterial pressure response to exercise was attenuated in cancer therapies compared to controls (107.8±10.8 vs 119.2±16.2 mm Hg). LEVTi was lower in cancer therapies compared to controls.

Conclusions

These data suggest an attenuated exercise blood flow response in cancer survivors ≈34 months following adjuvant cancer therapy that may be attributed to an attenuated increase in mean arterial pressure.

Resistance training attenuates the effects of aging in the aorta of Wistar rats

Abstract The objective of the present study was to follow the structural modifications of the aortic wall in middle-aged rats submitted to a resistance training protocol for a period of four months. Three groups of 8 animals per group were considered: middle-aged group (MA), old control group (OC) and old trained group (OT). Training consisted in to climb a 1.1-m vertical (80° incline) ladder with weights tied to their tail. Aortic wall structural modifications were studied through light and electron microscopy and morphometry. The mean arterial blood pressure at rest was similar in the three experimental groups (p = .07). At the beginning of the experiment, the OC and OT groups had similar repetition maximums, ranging from 1.6-fold to 1.9-fold the body weight. At the end of the experiment, the repetition maximum of the OT group was 5-fold greater than the body weight (p = .03). The LV weight was 15% larger in the OT group than in the MA group and 12% larger than in the OC group (p = .02). The LV wall thickness of the OT group was significantly larger than that of both, the MA group and the OC group (p = .03). The LV internal diameter in the OT group was significantly smaller than that observed in the MA and OC groups (p = .02). Resistance training diminished the alterations associated with aging improving aortic wall structure by reducing the thickness, normalising the elastic material, the collagen and the smooth muscle cells. Resistance training seems to be a potential treatment for reducing the deleterious effects of aging on the aortic wall.

Skeletal muscle as an endocrine organ: PGC-1α, myokines and exercise

An active lifestyle is crucial to maintain health into old age; inversely, sedentariness has been linked to an elevated risk for many chronic diseases. The discovery of myokines, hormones produced by skeletal muscle tissue, suggests the possibility that these might be molecular mediators of the whole body effects of exercise originating from contracting muscle fibers. Even though less is known about the sedentary state, the lack of contraction-induced myokines or the production of a distinct set of hormones in the inactive muscle could likewise contribute to pathological consequences in this context. In this review, we try to summarize the most recent developments in the study of muscle as an endocrine organ and speculate about the potential impact on our understanding of exercise and sedentary physiology, respectively. This article is part of a Special Issue entitled "Muscle Bone Interactions".

Skeletal Muscle Changes in Chronic Cardiac Disease and Failure

Peak exercise performance in healthy man is limited not only by pulmonary or skeletal muscle function but also by cardiac function. Thus, abnormalities in cardiac function will have a major impact on exercise performance. Many cardiac diseases affect exercise performance and indeed for some cardiac conditions such as atherosclerotic heart disease, exercise testing is frequently used not only to measure functional capacity but also to make a diagnosis of heart disease, evaluate the efficacy of treatment, and predict prognosis. Early in the course of cardiac diseases, exercise performance will be minimally affected but with disease progression impairment in exercise capacity will become apparent. Ejection fraction, that is, the percent of blood volume ejected with each cardiac cycle is often used as a measure of cardiac performance but frequently there is a dissociation between the ejection fraction and exercise capacity in patients with heart disease. How abnormalities in cardiac function impacts the muscles, vasculature, and lungs to impact exercise performance will here be reviewed. The focus of this work will be on patients with systolic heart failure as the incidence and prevalence of heart failure is reaching epidemic proportions and heart failure is the end result of many other chronic cardiac diseases. The prognostic role of exercise and benefits of exercise training will also be discussed.

Cardiac rehabilitation in patients with type 2 diabetes mellitus and coronary disease: a comparative study

INTRODUCTION AND AIMS

Diabetic patients have a 2-4 times higher risk of cardiovascular disease than non-diabetic individuals. The aims of this study are to evaluate the effects of a cardiac rehabilitation program (phase II) in patients with diabetes and coronary disease and to compare the results with regard to control of cardiovascular risk factors and improvement in functional capacity with coronary patients without diabetes.

METHODS

This was a prospective study of patients diagnosed with ischemic heart disease referred for a cardiac rehabilitation program between January 2009 and June 2013. The population was divided into two groups: diabetic and non-diabetic. Patients were assessed at the beginning of phase II and three months later and the following parameters were recorded: body mass index, waist circumference, lipid profile, blood glucose and glycated hemoglobin in diabetic patients, blood pressure, smoking, physical activity level (using the International Physical Activity Questionnaire) and functional capacity (on treadmill stress testing).

RESULTS

The study population consisted of 682 patients (253 diabetic and 429 non-diabetic). Diabetic patients were significantly older, had a worse cardiovascular risk profile (higher prevalence of overweight, dyslipidemia, hypertension and sedentary lifestyle) and lower functional capacity. At the end of phase II, there was a statistically significant improvement (p<0.05) in all risk factors and functional capacity, which was similar in both groups, except for body mass index, triglycerides and functional capacity.

CONCLUSIONS

Diabetic patients may benefit from a cardiac rehabilitation program and achieve comparable results to non-diabetic patients.

Exercise prevents leptin-induced increase in blood pressure in Sprague-Dawley rats

Although leptin has been shown to increase blood pressure (BP), it is however unclear if this increase can be prevented by exercise. This study therefore investigated the effect of leptin treatment with concurrent exercise on blood pressure (BP), sodium output, and endothelin-1 (ET-1) levels in normotensive rats. Male Sprague-Dawley rats weighing 250-270 g were divided into four groups consisting of a control group (n = 6), leptin-treated (n = 8), non-leptin-treated exercise group (n = 8), and a leptin-treated exercise group (n = 8). Leptin was given subcutaneously daily for 14 days (60 μg/kg/day). Animals were exercised on a treadmill for 30 min at a speed of 0.5 m/s and at 5° incline four times per week. Measurement of systolic blood pressure (SBP) and collection of urine samples for estimation of sodium and creatinine was done once a week. Serum samples were collected at the end of the experiment for determination of sodium, creatinine and ET-1. At day 14, mean SBP and serum ET-1 level in the leptin-treated group was significantly higher than that in the control group whereas mean SBP and serum ET-1 level was significantly lower in the leptin-treated exercise group than those in leptin-treated and control groups. Creatinine clearance, urinary sodium excretion, and urine output were not different between the four groups. Regular treadmill exercise prevents leptin-induced increases in SBP in rats, which might in part result from increased urinary sodium excretion and preventing the leptin-induced increases in serum ET-1 concentration.

Physical activity, health benefits, and mortality risk

A plethora of epidemiologic evidence from large studies supports unequivocally an inverse, independent, and graded association between volume of physical activity, health, and cardiovascular and overall mortality. This association is evident in apparently healthy individuals, patients with hypertension, type 2 diabetes mellitus, and cardiovascular disease, regardless of body weight. Moreover, the degree of risk associated with physical inactivity is similar to, and in some cases even stronger than, the more traditional cardiovascular risk factors. The exercise-induced health benefits are in part related to favorable modulations of cardiovascular risk factors observed by increased physical activity or structured exercise programs. Although the independent contribution of the exercise components, intensity, duration, and frequency to the reduction of mortality risk is not clear, it is well accepted that an exercise volume threshold defined at caloric expenditure of approximately 1,000 Kcal per week appears to be necessary for significant reduction in mortality risk. Further reductions in risk are observed with higher volumes of energy expenditure. Physical exertion is also associated with a relatively low and transient increase in risk for cardiac events. This risk is significantly higher for older and sedentary individuals. Therefore, such individuals should consult their physician prior to engaging in exercise.

“Walking is man’s best medicine”

Hippocrates

[Hypertension and exercise]

Levels of physical activity in modern urbanized society are clearly insufficient to maintain good health, and to prevent cardiovascular and other disease. Aerobic exercise is almost completely free of secondary effects, and is a useful adjunctive therapy in treating hypertension. There are several possible mechanisms to account for the beneficial effects of exercise in reducing blood pressure, the resulting physiological effects usually being classified as acute, post-exercise or chronic. Variations in genetic background, hypertension etiology, pharmacodynamics and pharmacokinetics may explain the different blood pressure responses to exercise among hypertensive patients. The present review discusses the different pathophysiological aspects of the response to exercise in hypertensives, including its modulators and diagnostic and prognostic usefulness, as well as the latest guidelines on prescribing and monitoring exercise regimes and drug therapy in the clinical follow-up of active hypertensive patients.

Lifestyle interventions for cardiovascular risk reduction in women with breast cancer

PURPOSE

The purpose of this paper is to identify risk factors for cardiovascular disease in women with breast cancer and review healthy lifestyle behaviors as essential risk reduction strategies.

FINDINGS

Women with breast cancer account for 22% of the 12 million cancer survivors. Women diagnosed with breast cancer often present with modifiable and non-modifiable cardiovascular risk factors and/or pre-existing co-morbid illness. Any one or a combination of these factors may increase the risk of cardiovascular disease. There is strong evidence that healthy eating and routine physical activity can reduce cardiovascular disease. Exercise improves cardiovascular fitness, body composition and quality of life in breast cancer survivors and observational studies suggest a survival benefit.

CLINICAL IMPLICATIONS

Lifestyle interventions including a healthy diet, regular physical activity, weight management and smoking cessation should be integrated into a survivorship care plan to reduce cardiovascular disease risk and promote better health for women with breast cancer.

Physical inactivity and mortality risk

In recent years a plethora of epidemiologic evidence accumulated supports a strong, independent and inverse, association between physical activity and the fitness status of an individual and mortality in apparently healthy individuals and diseased populations. These health benefits are realized at relatively low fitness levels and increase with higher physical activity patterns or fitness status in a dose-response fashion. The risk reduction is at least in part attributed to the favorable effect of exercise or physical activity on the cardiovascular risk factors, namely, blood pressure, diabetes mellitus and obesity. In this review, we examine evidence from epidemiologic and interventional studies in support of the association between exercise and physical activity and health. In addition, we present the exercise effects on the aforementioned risk factors. Finally, we include select dietary approaches and their impact on risk factors and overall mortality risk.

Regular thermal therapy may promote insulin sensitivity while boosting expression of endothelial nitric oxide synthase--effects comparable to those of exercise training

Regular thermal therapy, using saunas or hot baths, has the potential to improve impaired insulin sensitivity and boost endothelial expression of the "constitutive" isoform of nitric oxide synthase--effects, analogous to those of aerobic training that should promote vascular health. Previous clinical reports suggest that hot tubs may be beneficial for diabetic control, and that sauna therapy can decrease blood pressure in essential hypertension and provide symptomatic benefit in congestive heart failure. For those who lack ready access to a sauna or communal hot tub, regular hot baths at home may suffice as practical thermal therapy. Thermal therapy might be viewed as an alternative to exercise training in patients too physically impaired for significant aerobic activity.

Effect of 4 weeks of aerobic or resistance exercise training on arterial stiffness, blood flow and blood pressure in pre- and stage-1 hypertensives

The benefits of aerobic exercise (AE) training on blood pressure (BP) and arterial stiffness are well established, but the effects of resistance training are less well delineated. The purpose of this study was to determine the impact of resistance vs aerobic training on haemodynamics and arterial stiffness. Thirty pre- or stage-1 essential hypertensives (20 men and 10 women), not on any medications, were recruited (age: 48.2 +/- 1.3 years) and randomly assigned to 4 weeks of either resistance (RE) or AE training. Before and after training, BP, arterial stiffness (pulse wave velocity (PWV)) and vasodilatory capacity (VC) were measured. Resting systolic BP (SBP) decreased following both training modes (SBP: RE, pre 136 +/- 2.9 vs. post 132 +/- 3.4; AE, pre 141 +/- 3.8 vs. post 136 +/- 3.4 mm Hg, P = 0.005; diastolic BP: RE, pre 78 +/- 1.3 vs post 74 +/- 1.6; AE, pre 80 +/- 1.6 vs. post 77 +/- 1.7 mm Hg, P = 0.001). Central PWV increased (P = 0.0001) following RE (11 +/- 0.9-12.7 +/- 0.9 ms(-1)) but decreased after AE (12.1 +/- 0.8-11.1 +/- 0.8 m s(-1). Peripheral PWV also increased (P = 0.013) following RE (RE, pre 11.5 +/- 0.8 vs. post 12.5 +/- 0.7 ms(-1)) and decreased after AE (AE, pre 12.6 +/- 0.8 vs post 11.6 +/- 0.7 m s(-1)). The VC area under the curve (VC(AUC)) increased more with RE than that with AE (RE, pre 76 +/- 8.0 vs. post 131.1 +/- 11.6; AE, pre 82.7 +/- 8.0 vs. post 110.1 +/- 11.6 ml per min per s per 100 ml, P = 0.001). Further, peak VC (VCpeak) increased more following resistance training compared to aerobic training (RE, pre 17 +/- 1.9 vs. post 25.8 +/- 2.1; AE, pre 19.2 +/- 8.4 vs post 22.9 +/- 8.4 ml per min per s per 100 ml, P = 0.005). Although both RE and AE training decreased BP, the change in pressure may be due to different mechanisms.

Exercise capacity and mortality in hypertensive men with and without additional risk factors

We assessed the association between exercise capacity and mortality in hypertensive men with and without additional cardiovascular risk factors. A cohort of 4631 hypertensive veterans, who successfully completed a graded exercise test at the Veterans Affairs Medical Center in Washington, DC, and Palo Alto, California, was followed for 7.7+/-5.4 years (35,629 person-years) for all-cause mortality. Fitness categories were established based on peak metabolic equivalent (MET) levels achieved. In each fitness category, we defined individuals with and without additional cardiovascular risk factors. Exercise capacity was the strongest predictor of all-cause mortality. The adjusted mortality risk was 13% lower for every 1-MET increase in exercise capacity. Compared with the very low fit (< or =5.0 MET), the adjusted risk was 34% lower for those achieving 5.1 to 7.0 MET (low fit; hazard ratio: 0.66; CI: 0.58 to 0.76; P<0.001), 59% lower for the moderate fit (7.1 to 10.0 MET; hazard ratio: 0.41; CI: 0.35 to 0.50; P<0.001), and 71% lower for the high-fit category (>10.0 MET; hazard ratio: 0.29; CI: 0.21 to 0.40; P<0.001). Within the very-low-fit category, mortality risk was 47% higher for those with additional risk factors compared with individuals with no risk factors. This risk was eliminated for those in the next fitness category (5.1 to 7.0 MET) and was progressively reduced for the moderate and high-fit categories regardless of the presence or absence of additional risk factors. In conclusion, exercise capacity was the strongest predictor of all-cause mortality in hypertensive men. The increased risk imposed by low fitness and additional cardiovascular risk factors was eliminated by relatively small increases in exercise capacity and declined progressively with higher exercise capacity.

Health, Medical Risk Factors, and Bicycle Use in Everyday Life in the Over-50 Population

Few middle-aged and elderly people get enough exercise from sports or leisure-time physical activity. Therefore, the impact of everyday physical activity on health is a matter of interest. The main objective of this study was to establish whether bicycle use in everyday life is positively associated with health. A sample of 982 randomly selected men and 1,020 women age 50–70 were asked in a computer-assisted telephone interview to provide information including a self-assessment of their health and physical activity. Self-assessed health correlates positively with bicycle use in everyday life (OR = 1.257; 95% CI: 1.031–1.532). Likewise, people who regularly cycle for transport are less likely to have medical risk factors (OR = 0.794; 95% CI: 0.652–0.967). This negative correlation is not diminished when sporting activity is controlled for. This indicates that positive effects of physical activity on risk factors can be also achieved solely by integrating more physical activity into routine everyday life.

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.

Short-term training effects on diastolic function in obese persons with the metabolic syndrome

The aim of this study was to determine the effects of a short-term high-intensity exercise program on diastolic function and glucose tolerance in obese individuals with and without metabolic syndrome (MetSyn). Obese men and women (BMI > 30 kg/m(2); 39-60 years) with and without the MetSyn (MetSyn 13; non-MetSyn 18) underwent exercise training consisting of 10 consecutive days of treadmill walking for 1 h/day at 70-75% of peak aerobic capacity. Subjects performed pre- and post-training testing for aerobic capacity, glucose tolerance (2-h meal test), and standard echocardiography. Aerobic capacity improved for both groups (non-MetSyn 24.0 +/- 1.6 ml/kg/min vs. 25.1 +/- 1.5 ml/kg/min; MetSyn 25.2 +/- 1.8 ml/kg/min vs. 26.2 +/- 1.7 ml/kg/min, P < 0.05). Glucose area under the curve (AUC) improved in the MetSyn group (1,017 +/- 58 pmol/l/min vs. 883 +/- 75 pmol/l/min, P < 0.05) with no change for the non-MetSyn group (685 +/- 54 pmol/l/min vs. 695 +/- 70 pmol/l/min). Isovolumic relaxation time (IVRT) improved in the MetSyn group (97 +/- 6 ms vs. 80 +/- 5 ms, P < 0.05), and remained normal in the non-MetSyn group (82 +/- 6 ms vs. 86 +/- 5 ms). No changes in other diastolic parameters were observed. The overall reduction in IVRT was correlated with a decrease in diastolic blood pressure (DBP) (r = 0.45, P < 0.05), but not with changes in glucose tolerance. Body weight did not change with training in either group. A 10-day high-intensity exercise program improved diastolic function and glucose tolerance in the group with MetSyn. The reduction in IVRT in MetSyn was associated with a fall in blood pressure. These data suggest that it may be possible to reverse early parameters of diastolic dysfunction in MetSyn with a high-intensity exercise program.

Physical activity and cardiovascular disease prevention: current recommendations

Epidemiologic studies support an inverse and robust relationship between physical activity (PA) and mortality risk, even after adjusting for potential confounding factors. The authors have reported 13% lower mortality risk for every 1-MET (metabolic equivalent) increase in exercise capacity. For those with an exercise capacity >7 METs, the mortality risk was approximately 50% to 70% lower when compared with those achieving <5 METs. The risk reduction is, at least in part, attributed to the favorable effect of PA on the cardiovascular risk factors. Increased PA lowers blood pressure in hypertensive individuals, increases high-density lipoprotein cholesterol in a dose-response fashion, and reduces the incidence of diabetes. The health benefits of PA can be realized by engaging in moderate-intensity physical activity (brisk walk) for at least 30 minutes per day, 5 days per week or vigorous activity (jogging) for 20 or more minutes, 3 days per week. Combinations of the 2 types of activity can also be performed.

[Instrument for the assessment of middle-aged and older adults' physical activity: design, eliability and application of the German-PAQ-50+]

Existing physical activity questionnaires have focused either on young and middle-aged adults or on the elderly. They have mainly assessed only a portion of possible physical activities or contained nation-specific sports. As there is no gold standard for a questionnaire-based assessment of physical activity in the over-50 population, recommendations for such a questionnaire relating to German-speaking countries were developed. This work included a systematic literature research, a survey of experts, and the design of a questionnaire based on validated measuring instruments. Finally, to test its reliability and application in the field, the complete questionnaire, including a retest, was applied by telephone interview (n = 57). The test-retest-correlation was r = 0.60 for the total time of physical activity and r = 0.52 for total energy expenditure. The researchers determined that the instrument is comprehensive in its coverage of all relevant domains of physical activity for the over-50 population; it is economically feasible and showed good acceptance.

Systemic and mitochondrial adaptive responses to moderate exercise in rodents

The systemic and nonmuscular adaptive response to moderate exercise is reviewed and compared with muscle responses to moderate and exhaustive exercise. Rats participating in voluntary wheel running and mice subjected to treadmill exercise on a lifelong basis showed 10-19% increased median life span. Mice also showed improved neurological functions, such as better (35-216%) neuromuscular coordination (tightrope test) and better (11-27%) exploratory activity (T maze). These effects are consistent with the systemic effects of moderate exercise lowering hyperglycemia, hypercholesterolemia, and hypertension. Mitochondria isolated from brain, liver, heart, and kidney of exercised mice show a 12-32% selectively increased complex IV activity, with a significant correlation between complex IV activity and performance in the tightrope test. Chronic exercise decreases (10-20%) the mitochondrial content of TBARS and protein carbonyls in the four organs after 24 weeks of training. Protein carbonyls were linearly and negatively related to complex IV activity. Exercise increased the levels of nNOSmu in human muscle and of nNOS in mouse brain. It is concluded that chronic moderate exercise exerts a whole-body beneficial effect that exceeds muscle adaptation, likely through mechanosensitive afferent nerves and beta-endorphin release to brain and plasma that promote mitochondrial biogenesis in distant organs.

Health promotion in later life: it's never too late

The clinical and epidemiological rationale for the health improvement benefits of health promotion in the later years of life are provided in this article. The authors review the emerging scientific consensus concerning the utility of lifestyle interventions for health improvement in the context of a narrowed definition of health promotion. Governmental initiatives for testing health promotion among Medicare beneficiaries are also discussed. Major research findings are reviewed and implications for health promotion practioners are also provided.

The effects of aerobic and resistance exercises in obese women

OBJECTIVE

To compare the effects of aerobic and resistance exercise on weight, muscle strength, cardiovascular fitness, blood pressure and mood in obese women who were not on an energy-restricted diet.

DESIGN

Randomized, prospective, controlled trial.

SETTING

Department of Physical Medicine and Rehabilitation, University Hospital.

SUBJECTS

Sixty obese women were assigned to one of three groups: aerobic exercise (n = 20), resistance exercise (n = 20) and control group (n = 20).

INTERVENTIONS

The aerobic exercise group performed both walking and leg cycle exercise with increasing duration and frequency. The resistance exercise group performed progressive weight-resistance exercises for the upper and lower body.

MAIN OUTCOME MEASURES

Before and after a 12-week period, all subjects were evaluated by anthropometric measurement, rating of mood, cardiorespiratory capacity and maximum strength of trained muscles.

RESULTS

After a 12-week training period, subjects in the resistance group showed significant improvement in one-repetition maximum test of hip abductors (7.95+/-3.58 kg), quadriceps (14+/-7.18 kg), biceps (3.37+/- 2.84 kg) and pectorals (8.75+/-5.09 kg) compared with those in the control group (P < 0.001). VO2 max increased (0.51+/-0.40) and Beck Depression Scale scores decreased (-5.40+/-4.27) in the aerobic exercise group compared with the control group, significantly (P < 0.001). Only in hip abductor muscle strength was there a significant increase in the resistance exercise group compared with the aerobic exercise group (P < 0.05).

CONCLUSION

Both aerobic exercise and resistance exercise resulted in improved performance and exercise capacity in obese women. While aerobic exercise appeared to be beneficial with regard to improving depressive symptoms and maximum oxygen consumption, resistance exercise was beneficial in increasing muscle strength.

Exercise in the Elderly: Research and Clinical Practice

Exercise programs for elderly patients have received much attention recently for their potential role in preventing illness and injury, limiting functional loss and disability, and alleviating the course and symptoms of existing cardiac, pulmonary, and metabolic disorders. The basic components of an exercise training program include strength, endurance, balance, and flexibility. This article reviews the main attributes of each, along with some of the most recent research defining their roles in health care. Where available, it discusses specific recommendations for prescribing exercise modalities. Finally, it presents suggestions for developing integrated exercise programs and enhancing patient compliance.

Rapid onset and offset of circulatory adaptations to exercise training in men

Chronic aerobic exercise lowers blood pressure (BP), peripheral resistance and cardiac work, and is used widely in antihypertensive and cardiac rehabilitation programmes. In this study, we tested the hypothesis that the cardiovascular benefits of training would occur progressively over several weeks and would diminish over a similar time course on termination of training. In all, 17 young, healthy men undertook a 4-week programme of cycle ergometry (30 min at 60% VO2peak 3-4 times/week) and 13 subjects matched for age, body mass index and fitness acted as controls. Resting BP and rate-pressure product (RPP) had fallen significantly after only 1 week's training and reached a nadir after 2 weeks training. At this time, BP had fallen from 121+/-7/66+/-6 to 110+/-5/57+/-7 mmHg and resting RPP had fallen from 85+/-10 to 71+/-9 (mmHg (beats min-1))-2 (P<0.001 each). In parallel, resting forearm conductance had risen from 0.026+/-0.010 to 0.052+/-0.029 (ml min-1) 100 ml-1 mmHg-1 and peak reactive hyperaemia following 3 min brachial artery occlusion was increased from 0.105+/-0.031 to 0.209+/-0.041 (ml min-1) 100 ml-1 mmHg-1 (P<0.001 each). No significant further circulatory changes occurred over weeks 3-4 of training. On cessation of training, all values returned to pretraining levels within between 1 (SBP, RPP, vascular conductance) and 2 (DBP, MAP, heart rate, reactive hyperaemia) weeks. The results indicate that the optimal cardiovascular benefits of moderate exercise occur rapidly. At least with short training programmes, the benefits regress once training stops just as quickly as they appeared.

Exercise training attenuates blood pressure elevation and adverse remodeling in the aorta of spontaneously hypertensive rats

OBJECTIVE

To observe the extracellular matrix modifications and quantify the structural alterations of the aortic wall in spontaneously hypertensive rats (SHR) submitted to an aerobic physical activity (PA) protocol.

MATERIAL AND METHODS

Three groups of five rats each were studied: sedentary normotensive Wistar rats (SED-Wistar) and SHR (divided in SHR that underwent a 1 h/day 5 days/week PA for 20 weeks (EX-SHR) and those that were restricted to cage-bound activity (SED-SHR).

RESULTS

BP was lower in EX-SHRs and SED-Wistar rats (-35%) than in SED-SHRs. This difference became significant from the 3rd week of PA. The wall thickness was smaller in the EX-SHR and SED-Wistar (-45%) than in the SED-SHR (p<0.0001). In EX-SHR group, oxytalan and elaunin fibers were more pronounced than in the other groups, while SED-SHR and SED-Wistar rats showed an equivalent appearance of aortic elaunin fibers. EX-SHR and SED-Wistar rats showed more than 65% greater smooth muscle nuclei numerical density per unit area than SED-SHRs while SED-SHRs showed more than 45% smaller surface density of lamellae than both EX-SHR and SED-Wistar rats. However, no quantitative differences were found in the aortic wall comparing EX-SHR and SED-Wistar rats.

CONCLUSION

PA might alter the aortic wall remodeling to adapt the artery to a hyperkinetic blood flow resulting in alterations of the extracellular matrix modulation and vascular resistance.