Regular physical activity prevents development of left ventricular hypertrophy in hypertension

Beneficial Effects of Exercise on Hypertension-Induced Cardiac Hypertrophy in Adolescents and Young Adults

PURPOSE OF REVIEW

Hypertension-induced cardiac hypertrophy is widely known as a major risk factor for increased cardiovascular morbidity and mortality. Although exercise is proven to exert overall beneficial effects on hypertension and hypertension-induced cardiac hypertrophy, there are some concerns among providers about potential adverse effects induced by intense exercise, especially in hypertensive athletes. We will overview the underlying mechanisms of physiological and pathological hypertrophy and delineate the beneficial effects of exercise in young people with hypertension and consequent hypertrophy.

RECENT FINDINGS

Multiple studies have demonstrated that exercise training, both endurance and resistance types, reduces blood pressure and ameliorates hypertrophy in hypertensives, but certain precautions are required for hypertensive athletes when allowing competitive sports: Elevated blood pressure should be controlled before allowing them to participate in high-intensity exercise. Non-vigorous and recreational exercise are always recommended to promote cardiovascular health. Exercise-induced cardiac adaptation is a benign and favorable response that reverses or attenuates pathological cardiovascular remodeling induced by persistent hypertension. Exercise is the most effective nonpharmacological treatment for hypertensive individuals. Distinction between recreational-level exercise and competitive sports should be recognized by medical providers when allowing sports participation for adolescents and young adults.

Association between leisure sedentary behaviors and hypertension risk: A prospective cohort study and two-sample Mendelian randomization analysis in Europeans

OBJECTIVE

This study aimed to investigate the potential causal relationship between domain-specific sedentary behaviors (including television watching, computer use, and driving) and hypertension risk in European populations.

METHODS

Initially, we conducted a multivariable Cox regression analysis to evaluate the associations between domain-specific sedentary behaviors and the risk of developing hypertension using data from 261,829 hypertension-free participants in the UK Biobank. To validate the findings of observational analysis, we employed two-sample univariable mendelian randomization (UVMR) analysis utilizing summary statistics from genome-wide association study conducted on European populations. We then performed multivariable mendelian randomization (MVMR) analysis to account for the influence of the risk factors for hypertension.

RESULTS

In this prospective observational analysis, individuals who spent >3 h per day watching television had significantly higher risk of developing hypertension (HR = 1.24, 95% CI: 1.20-1.29, P < 0.001) compared to those who watched television for 0-1 h per day. The mendelian randomization analysis provided consistent evidence for a causal relationship between prolonged television watching time and hypertension risk (OR = 1.45, 95% CI: 1.25-1.69, P < 0.001; all PMVMR < 0.05) in both UVMR and MVMR results. No significant associations were found between computer use, driving behaviors and the risk of hypertension in either the observational or UVMR/MVMR analyses.

CONCLUSIONS

These findings provide evidence for a causal effect specifically linking higher television watching time to an increased risk of hypertension and indicate the potential effectiveness of reducing television viewing time as a preventive measure to mitigate the risk of hypertension.

Upregulation of mitochondrial telomerase reverse transcriptase mediates the preventive effect of physical exercise on pathological cardiac hypertrophy via improving mitochondrial function and inhibiting oxidative stress

Physical exercise is a non-pharmacological intervention that helps prevent pathological cardiac hypertrophy. However, the underlying molecular mechanisms remain unclear. Telomerase reverse transcriptase (TERT) has non-telomeric functions such as protection against mitochondrial dysfunction and oxidative stress, and its myocardial expression is upregulated by physical exercise. Here, we found that physical exercise caused myocardial upregulation of mitochondrial TERT and sustenance during transverse aortic constriction (TAC)-induced cardiac hypertrophy. Overexpression of mitochondrial-targeted TERT (mito-TERT) via adeno-associated virus serotype 9 carrying the TERT-coding sequence fused with N-terminal mitochondrial-targeting sequence improved cardiac function and attenuated cardiac hypertrophy. Mechanistically, mito-TERT ameliorated mitochondrial dysfunction and oxidative stress, which were associated with improving the activity and subunit composition of complex I. Remarkably, the telomerase activator TA-65 also exhibited an antihypertrophic effect. Collectively, our results reveal a significant role for mito-TERT in mediating the antihypertrophic effect of physical exercise and demonstrate that TERT is a potential drug target for treating cardiac hypertrophy.

Effects of Different Kinds of Physical Activity on Vascular Function

Regular exercise is one of the main non-pharmacological measures suggested by several guidelines to prevent and treat the development of hypertension and cardiovascular disease through its impact on the vascular system. Routine aerobic training exerts its beneficial effects by means of several mechanisms: decreasing the heart rate and arterial pressure as well as reducing the activation of the sympathetic system and inflammation process without ignoring the important role that it plays in the metabolic profile. Through all these actions, physical training counteracts the arterial stiffening and aging that underlie the development of future cardiovascular events. While the role of aerobic training is undoubted, the effects of resistance training or combined-training exercise on arterial distensibility are still questioned. Moreover, whether different levels of physical activity have a different impact on normotensive and hypertensive subjects is still debated.

Exercise Effects on Left Ventricular Remodeling in Patients with Cardiometabolic Risk Factors

Left ventricular (LV) remodeling is a dynamic process, which is characterized by changes in ventricular size, shape, and wall thickness, thus altering myocardial geometry and function, and is considered as a negative prognostic factor in patients with heart failure (HF). Hypertension, type 2 diabetes (T2D), and obesity are strongly correlated with the development and the progression of LV remodeling, LV hypertrophy, and LV systolic and/or diastolic dysfunction. Indeed, the beneficial impact of exercise training on primary and secondary prevention of cardiovascular disease (CVD) has been well-established. Recent studies have highlighted that exercise training enhances functional capacity, muscle strength and endurance, cardiac function, and cardiac-related biomarkers among patients with established coronary artery disease (CAD) or HF, thus substantially improving their cardiovascular prognosis, survival rates, and need for rehospitalization. Therefore, in this review article, we discuss the evidence of LV remodeling in patients with cardiometabolic risk factors, such as hypertension, T2D, and obesity, and also highlight the current studies evaluating the effect of exercise training on LV remodeling in these patients.

Sedentary Behavioral Studies of Young and Middle-Aged Adults with Hypertension in the Framework of Behavioral Epidemiology: A Scoping Review

(1) Background: As times change, the detection rate of hypertension is increasing in the young and middle-aged population due to prevalent sedentary behaviors. The purpose of this study was to conduct a scoping review to identify and summarize the research on sedentary behavior in this population by separating it into five stages: the relationship between sedentary behavior and health; measurement modalities; influencing factors; interventions; and translational research in young and middle-aged adults with hypertension. (2) Methods: Using a scoping review research approach, the PubMed, Web of Science Core Collection, and MEDLINE databases were used to search for the literature on this subject from the date of the database's creation to 14 June 2022, and the behavioral epidemiology framework was used to classify the retrieved articles. (3) Results: A total of eight articles were included. Among them, there were six articles on the relationship between behavior and health, which includes blood pressure, insulin resistance, and the cardiovascular system; one article on the study of measurement methods, which was used for clinical decision making through decision trees; one article on influencing factors, which was divided into intrinsic and extrinsic factors; and no articles on intervention program development or the translation of intervention programs to further practice in this population. (4) Conclusions: Sedentary behavioral studies of young and middle-aged adults with hypertension are scarce and are generally carried out in the early stages of the condition. In the future, in-depth studies can be conducted on the dose-response relationship between sedentary behavior and health in this population; the development of easier and targeted measurement tools; the exploration of more influencing factors; and the effectiveness and translation of intervention programs.

Regular physical activity: a major component of isolated systolic hypertension in the young

In the last few decades there has been much debate about the clinical significance of isolated systolic hypertension in youth (ISHY). Purpose of this article is to discuss the epidemiology and pathophysiology of ISHY focusing on the relationship between ISHY and aerobic exercise. There is evidence to suggest that regular physical activity produces favourable long-standing cardiovascular effects in young individuals including the improvement of arterial elasticity as measured from carotid-femoral pulse wave velocity and from small artery compliance. A recent ESH document recognises the heterogeneity of ISHY which may be associated with multiple factors that can interact to determine this BP phenotype. Several studies have shown that long-term training in aerobic sports is one main factor contributing to ISHY. In the athlete, the increased stroke volume secondary to low heart rate and the high arterial elasticity causes an increase in peripheral pulse pressure. This explains why ISHY is more common in physically trained than in sedentary individuals and is considered by some authors as a spurious hypertension. Recent results from the HARVEST study confirm the existence of an association between ISHY and endurance training. In that study the prevalence of ISHY was directly related to physical activity habits being 8.8% in the sedentary subjects and 25.7% in the athletes. Eligibility to competitive athletics of athletes with ISHY should be based on the results of 24-hour ambulatory BP monitoring and careful clinical assessment of all cardiovascular risk factors and target organ involvement in order to establish the global level of risk.

Leisure-Time Physical Activity Has a More Favourable Impact on Carotid Artery Stiffness Than Vigorous Physical Activity in Hypertensive Human Beings

Aim. To assess the effect of leisure time versus vigorous long-term dynamic physical activity (PA) on carotid stiffness in normotensive versus hypertensive subjects. Methods. The study was conducted on 120 leisure-time exercisers and 120 competitive athletes. One hundred and twenty sedentary subjects served as controls. In addition, participants were classified according to whether their systolic blood pressure was ≥130 mmHg (hypertensives, n = 120) or normal (normotensives, n = 240) according to the ACC/AHA 2017 definition. Carotid artery stiffness was assessed with an echo-tracking ultrasound system, using the pressure-strain elastic modulus (EP) and one-point pulse wave velocity (PWVβ) as parameters of stiffness. Results. The effect of the two levels of PA differed in the normotensives and the hypertensives. Among the normotensives, there was an ongoing, graded reduction in EP and PWVβ from the sedentary subjects to the athletes. By contrast, among the hypertensives, the lowest levels of EP and PWVβ were found among the leisure-time PA participants. EP and PWVβ did not differ between the hypertensive sedentary subjects and the athletes. A significant interaction was found between PA and BP status on EP (p = 0.03) and a borderline interaction on PWVβ (p = 0.06). In multiple regression analyses, PA was a negative predictor of EP (p = 0.001) and PWVβ (p = 0.0001). The strength of the association was weakened after the inclusion of heart rate in the models (p = 0.04 and 0.007, respectively). Conclusions. These data indicate that in people with hypertension, leisure-time PA has beneficial effects on carotid artery stiffness, whereas high-intensity chronic PA provides no benefit to vascular functions.

Left Ventricular Hypertrophy: Etiology-Based Therapeutic Options

Determining the etiologies of left ventricular hypertrophy (LVH) can be challenging due to the similarities of the different manifestations in clinical presentation and morphological features. Depending on the underlying cause, not only left ventricular mass but also left ventricular cavity size, or both, may increase. Patients with LVH remain asymptomatic for a few years, but disease progression will lead to the development of systolic or diastolic dysfunction and end-stage heart failure. As hypertrophied cardiac muscle disrupts normal conduction, LVH predisposes to arrhythmias. Distinguishing individuals with treatable causes of LVH is important for prevention of cardiovascular events and mortality. Athletic's heart with physiological LVH does not require treatment. Frequent causes of hypertrophy include etiologies due to pressure/volume overload, such as systemic hypertension, hypertrophic cardiomyopathy, or infiltrative cardiac processes such as amyloidosis, Fabry disease, and sarcoidosis. Hypertension and aortic valve stenosis are the most common causes of LVH. Management of LVH involves lifestyle changes, medications, surgery, and implantable devices. In this review we systematically summarize treatments for the different patterns of cardiac hypertrophy and their impacts on outcomes while informing clinicians on advances in the treatment of LVH due to Fabry disease, cardiac amyloidosis, and hypertrophic cardiomyopathy.

Characteristics of the athlete's heart in aged hypertensive and normotensive subjects

BACKGROUND

Both hypertension and age-related impairment of the cardiac condition are known to be improved by regular physical training. As relatively few studies have been reported about the older, hypertensive patients, the aim of this study was to establish cardiac benefits of active lifestyle in these subjects.

METHODS

Two-dimensionally guided M-mode, Doppler- and tissue Doppler echocardiography was performed in 199 normo- and hypertensive, active and sedentary older (age>60 yrs.) men (111) and women (88). Results were compared either by ANOVA, or by Kruskall-Wallis test.

RESULTS

The left ventricular muscle index (LVMI), which is higher in young active than in sedentary persons, proved to be smaller in the active than sedentary older subjects: men normotensives: actives 83 vs. sedentary ones 98, hypertensives: actives 88 vs. sedentary ones 107, women normotensives: actives 77 vs. sedentary ones 89 g/m3. Diastolic function was better in the active groups demonstrated both by the ratio of the early to atrial peak blood flow velocities (men: normotensives: actives 1.03 vs. sedentary ones 0.76, women normotensives: actives 1.21 vs. sedentary ones 0.9, hypertensives: actives 1.04 vs. sedentary ones 0.88). The tissue Doppler results were also better in the active groups; the difference between the active and sedentary groups was more marked in the normotensive male groups than in the hypertensive ones.

CONCLUSIONS

Active lifestyle prevents age-related pathological LV hypertrophy, and attenuates the LV diastolic dysfunction.

Association between self-reported physical activity and indicators of cardiovascular risk in community-dwelling older adults with hypertension in Korea: A cohort study

The prevalence of hypertension has increased with the rise in the elderly population, and high blood pressure is a major cause of cardiovascular disease. Physical activity is an important strategy for preventing cardiovascular disease. The study aimed to explore the association between physical activity and cardiovascular risk indicators in community-dwelling older adults with hypertension.This study is a secondary data analysis of a prospective longitudinal study using data from the Elderly Cohort Database of the National Health Insurance Service in South Korea between 2002 and 2013. Participants included 10,588 older adults (≥60 years) with hypertension. Data assessing self-reported physical activity and directly measured blood pressure, fasting blood glucose, body mass index, and total cholesterol levels throughout the 12-year study were extracted from the original database and analyzed. Participants were categorized into 4 groups based on the reported changes in physical activity over time: Group I (Maintaining No Physical Activity Group), II (Changing from No Physical Activity to Physical Activity Group), III (Changing from Physical Activity to No Physical Activity Group), and IV (Maintaining Physical Activity Group). Cox proportional hazard model was used to confirm the risk of cardiovascular indicators over time in each group.Participants' mean age was 64.2 years in the initial year of 2002. The number of participants in Groups I, II, III, and IV was 4032, 2697, 1919, and 1940, respectively. Group IV showed a significant decline in risk for uncontrolled hypertension compared to Group I (hazard ratio = 0.87, 95% confidence interval [0.800-0.948]). Group II showed a significant decrease in risk for uncontrolled diabetes compared to Group I (hazard ratio = 0.94, 95% confidence interval [0.888-0.999]).The findings indicated that physical activity is a significant factor associated with indicators of cardiovascular risk in older people with high blood pressure. Healthcare providers should be aware of the importance of older adults' physical activity and encourage them to perform and maintain it steadily for better long-term cardio-metabolic outcomes.

The HARVEST. Looking for optimal management of young people with stage 1 hypertension

In the last few decades there has been much debate about the management of low-risk stage 1 hypertension in youth. In this article, we review the main findings of the HARVEST cohort accrued over 30 years, highlighting the contribution of this study to the existing literature. Tachycardia and sympathetic overdrive were closely intertwined in our HARVEST participants, promoting the development of sustained hypertension, metabolic abnormalities, and increased susceptibility to vascular complications. Short-term blood pressure variability in this age group had a prognostic power even greater than that of average 24h blood pressure. In the HARVEST participants, changes in left ventricular anatomy and contractility were the earliest signs of hypertensive cardiac involvement, whereas left ventricular filling was only marginally affected. Our results highlighted the role of glomerular hyperfiltration in determining microalbuminuria and renal damage in the early stage of hypertension. The genetic approach provided an important contribution to risk stratification and patient management. The HARVEST confirmed the importance of maintaining a good lifestyle for preventing the onset of hypertension, diabetes and cardiovascular events. Isolated systolic hypertension in the first decades of life appeared as a heterogeneous condition. To establish whether antihypertensive drug treatment should be started in this condition the clinician should consider the individual cardiovascular risk profile, the level of office mean BP and central BP. Despite recent progress in our knowledge, systolic hypertension still represents a challenging issue for the clinician. Hopefully, the HARVEST will continue to contribute data that help to fill the present gaps in evidence.

Physical activity and sedentary behaviour in secondary prevention of coronary artery disease: A review

Comprehensive management of coronary artery disease (CAD) includes physical exercise as a part of daily lifestyle therapy. Still CAD patients generally have low physical activity (PA) and high sedentary behaviour (SB). This review summarizes the effect of exercise training and habitual PA and SB on physical fitness and quality of life (QoL) as well as on rehospitalizations and mortality in patients with stable CAD, recent acute coronary syndrome (ACS) or recent revascularization. A literature review of the influence of exercise, and PA and SB profiles in secondary prevention of CAD was performed using PubMed. All articles published between January 2001 and April 2019, meeting the inclusion criteria were considered. A total of 25 cross-sectional or prospective studies or randomized controlled trials (RCT) were included to this review. Exercise training was found to improve maximal oxygen consumption, QoL, and to reduce rehospitalizations and mortality among patients with established CAD. Remote PA interventions have not been as effective as the supervised exercise sessions in reducing the clinical endpoints. High SB, especially when combined to low PA, is associated with poor cardiorespiratory fitness and worse long-term prognosis among patients with ACS. In conclusion, exercise training and high PA are beneficial for patients with stable CAD, recent ACS or recent revascularization. High SB is associated with poor cardiopulmonary fitness and increased mortality in ACS patients. Novel tools using online applications and smart devices are promising means to offer remote guidance for PA among patients unable to participate in regular exercise sessions.

Physical activity and the risk of heart failure: a systematic review and dose-response meta-analysis of prospective studies

Although physical activity is an established protective factor for cardiovascular diseases such as ischemic heart disease and stroke, less is known with regard to the association between specific domains of physical activity and heart failure, as well as the association between cardiorespiratory fitness and heart failure. We conducted a systematic review and meta-analysis of prospective observational studies to clarify the relations of total physical activity, domains of physical activity and cardiorespiratory fitness to risk of heart failure. PubMed and Embase databases were searched up to January 14th, 2020. Summary relative risks (RRs) were calculated using random effects models. Twenty-nine prospective studies (36 publications) were included in the review. The summary RRs for high versus low levels were 0.77 (95% CI 0.70–0.85, I² = 49%, n = 7) for total physical activity, 0.74 (95% CI 0.68–0.81, I² = 88.1%, n = 16) for leisure-time activity, 0.66 (95% CI 0.59–0.74, I² = 0%, n = 2) for vigorous activity, 0.81 (95% CI 0.69–0.94, I² = 86%, n = 3) for walking and bicycling combined, 0.90 (95% CI 0.86–0.95, I² = 0%, n = 3) for occupational activity, and 0.31 (95% CI 0.19–0.49, I² = 96%, n = 6) for cardiorespiratory fitness. In dose–response analyses, the summary RRs were 0.89 (95% CI 0.83–0.95, I² = 67%, n = 4) per 20 MET-hours per day of total activity and 0.71 (95% CI 0.65–0.78, I² = 85%, n = 11) per 20 MET-hours per week of leisure-time activity. Nonlinear associations were observed in both analyses with a flattening of the dose–response curve at 15–20 MET-hours/week for leisure-time activity. These findings suggest that high levels of total physical activity, leisure-time activity, vigorous activity, occupational activity, walking and bicycling combined and cardiorespiratory fitness are associated with reduced risk of developing heart failure.

Is Exercise Helpful or Harmful in Dealing With Specific Arrhythmia

Exercise is universally known to benefit health by lowering risk for cardiovascular disease and mortality. However, in patients with pre-existing cardiac conditions, including channelopathies, cardiomyopathies and coronary artery disease, exercise can cause sudden cardiac death (SCD). In this review, we explore exercise related risks and current recommendations for specific conditions. The risk of myocardial infarction (MI) during strenuous exercise in asymptomatic individuals with coronary artery disease is decreased with habitual exercise, especially if they have a normal ejection fraction and no ischemia. Furthermore, cardiac rehabilitation has been shown to be beneficial in heart failure. On the other hand, surgery is recommended for certain anomalous coronaries prior to engaging in vigorous activity. In addition, both exercise-induced disease progression and SCD in arrhythmogenic cardiomyopathy restrict ability to engage in competitive sports, as is the case in hypertrophic cardiomyopathy. Other diseases, like myocarditis only cause temporary risk for SCD. Previously considered benign, common conditions like early repolarization do increase SCD risk. Finally, certain gear including thicker chest protectors for athletes engaging in sports with hard, small spherical objects decrease risk of commotio cordis. While significant advances have been achieved in diagnosing and treating previously unrecognized conditions that predispose to sudden cardiac death, more research is needed to further tailor recommendations to allow beneficial exercise in those with rarer conditions that are under-represented in large systemic studies.

Heart rate as cardiovascular risk factor

Heart rate is a parameter that is widely used by the general population as a marker of health. The availability of wearable electronic heart rate monitoring devices and use of specific apps are widely used both at rest and during daily life activities. Resting heart rate values gained more relevance with the evidence of association between elevated heart rate values at rest and diseases and adverse events. Also longitudinal studies demonstrated a clear association between increase in heart rate over time and cardiovascular and all-cause mortality. The increased knowledge of physiological mechanisms of heart rate control and the pathophysiological mechanisms responsible for its dysfunction allows identification of the cutoff value of normalcy. This information can be used to select non-pharmacological and pharmacological interventions to reduce the cardiovascular risk both in the general population and in patients with pathophysiological conditions. This review provides an overview of the current knowledge of resting heart rate as cardiovascular risk factor.

Level of Physical Activity, Left Ventricular Mass, Hypertension, and Prognosis

Left ventricular hypertrophy is a strong predictor of prognosis in hypertension. Physical activity is associated with higher left ventricular mass but also reduced risk of cardiovascular outcomes. The aims were to explore whether (1) presence of hypertension modifies the association between physical activity and left ventricular mass; (2) the beneficial association between physical activity and prognostic outcome is modified by left ventricular hypertrophy. Randomly selected number of 3078 persons from the general population underwent echocardiogram. Left ventricular mass was indexed to body surface area. Level of physical activity was self-reported: inactivity, light activity, and moderate/high activity. Blood pressure was measured in rest: normal BP (<140/90 mm Hg) and hypertension (≥140/90 mm Hg or in pharmacological treatment for hypertension). Presence of hypertension modified the association between physical activity and left ventricular mass index significantly (test for interaction: P =0.01): in normal BP, higher levels of physical activity were associated with significantly higher left ventricular mass index ( P <0.001), but this was not present in hypertension ( P =0.90). Level of physical activity was associated with reduction in mortality and cardiovascular outcome independent of the presence of LVH (Persons with LVH: light activity HR, 0.77 [0.52–1.15], moderate/high activity HR, 0.61 [0.38–0.97]; test for interaction between LVH and level of physical activity P =0.71). In conclusion, persons with normal BP had higher left ventricular mass index at increased levels of physical activity, whereas this association was not present among persons with hypertension. Level of physical activity was associated with better prognosis independent of whether left ventricular hypertrophy was present or not.

Left ventricular hypertrophy and hypertension

Hypertension (HTN) is a major modifiable risk factor for cardiovascular disease (CVD) morbidity and mortality. The left ventricle (LV) is a primary target for HTN end-organ damage. In addition to being a marker of HTN, LV geometrical changes: concentric remodeling, concentric or eccentric LV hypertrophy (LVH) are major independent risk factors for not only CVD morbidity and mortality but also for all-cause mortality and neurological pathologies. Blood pressure control with lifestyle changes and antihypertensive agents has been demonstrated to prevent and regress LVH. Herein, we provide a comprehensive review of literature on the relationship between HTN and LV geometry abnormalities with a focus on diagnosis, prognosis, pathophysiological mechanisms, and treatment approaches.

Exercise during transition from compensated left ventricular hypertrophy to heart failure in aortic stenosis rats

We evaluated the influence of aerobic exercise on cardiac remodelling during the transition from compensated left ventricular (LV) hypertrophy to clinical heart failure in aortic stenosis (AS) rats. Eighteen weeks after AS induction, rats were assigned into sedentary (AS) and exercised (AS-Ex) groups. Results were compared to Sham rats. Exercise was performed on treadmill for 8 weeks. Exercise improved functional capacity. Echocardiogram showed no differences between AS-Ex and AS groups. After exercise, fractional shortening and ejection fraction were lower in AS-Ex than Sham. Myocyte diameter and interstitial collagen fraction were higher in AS and AS-Ex than Sham; however, myocyte diameter was higher in AS-Ex than AS. Myocardial oxidative stress, evaluated by lipid hydroperoxide concentration, was higher in AS than Sham and was normalized by exercise. Gene expression of the NADPH oxidase subunits NOX2 and NOX4, which participate in ROS generation, did not differ between groups. Activity of the antioxidant enzyme superoxide dismutase was lower in AS and AS-Ex than Sham and glutathione peroxidase was lower in AS-Ex than Sham. Total and reduced myocardial glutathione, which is involved in cellular defence against oxidative stress, was lower in AS than Sham and total glutathione was higher in AS-Ex than AS. The MAPK JNK was higher in AS-Ex than Sham and AS groups. Phosphorylated P38 was lower in AS-Ex than AS. Despite improving functional capacity, aerobic exercise does not change LV function in AS rats. Exercise restores myocardial glutathione, reduces oxidative stress, impairs JNK signalling and further induces myocyte hypertrophy.

Physical Activity Is Associated With Reduced Left Ventricular Mass in Obese and Hypertensive African Americans

BACKGROUND

Physical activity (PA) has been associated with decreased left ventricular (LV) hypertrophy in previous studies. However, little is known about the relationship between PA and LV structure and factors which influence this relationship among African Americans.

METHODS

We evaluated 1,300 African Americans with preserved LV ejection fraction (EF > 50%) from the Genetic Epidemiology Network of Arteriopathy (GENOA) Study (mean age 62.4 years, 73% women). PA index was calculated as 3 * heavy activity hours + 2 * moderate activity hours + slight activity hours/day. The relationship between PA index and LV structure was evaluated using generalized estimating equation. The association between PA index and LV mass index by age group, sex, body mass index (BMI), history of hypertension, diabetes or coronary heart disease, estimated glomerular filtration rate, and current smoking status were plotted.

RESULTS

After adjustment for these factors, higher PA index was independently associated with lower LV mass index (P < 0.05). There were significant interactions between PA index and obesity (BMI ≥ 30) and history of hypertension on LV mass index (P for interaction <0.05, for both). Higher PA index was associated with lower LV mass index more in obese or hypertensive participants compared with nonobese or nonhypertensive participants.

CONCLUSIONS

Higher PA index was associated with reduced LV hypertrophy in obese and hypertensive African Americans. Prospective studies aimed at assessing whether increasing PA prevents LV hypertrophy and potentially reduces the risk of heart failure in these at risk groups are warranted.

Current Perspectives on Left Ventricular Geometry in Systemic Hypertension

Hypertension (HTN) is a global health problem and a leading risk factor for cardiovascular disease (CVD) morbidity and mortality. The hemodynamic overload from HTN causes left ventricular (LV) remodeling, which usually manifests as distinct alterations in LV geometry, such as concentric remodeling or concentric and eccentric LV hypertrophy (LVH). In addition to being a common target organ response to HTN, LV geometric abnormalities are well-known independent risk factors for CVD. Because of their prognostic implications and quantifiable nature, changes in LV geometric parameters have commonly been included as an outcome in anti-HTN drug trials. The purpose of this paper is to review the relationship between HTN and LV geometric changes with a focus on (1) diagnostic approach, (2) epidemiology, (3) pathophysiology, (4) prognostic effect and (5) LV response to anti-HTN therapy and its impact on CVD risk reduction.

Cardiac structure and function and leisure-time physical activity in the elderly: The Atherosclerosis Risk in Communities Study

AIMS

Adults who engage in leisure-time physical activity (LTPA) have a reduced risk of developing heart failure. We hypothesized that high levels of LTPA are associated with diminished adverse age-related changes in cardiac structure and function.

METHODS AND RESULTS

We studied 4342 Atherosclerosis Risk in Communities Study participants free of cardiovascular disease who underwent standardized echocardiography. In a cross-sectional analysis, we related LTPA (poor, intermediate, or ideal) to cardiac structure and function. We also related cumulative average LTPA over 24 years and changes in LTPA categories to echocardiographic measures. Cross-sectional analysis demonstrated that ideal LTPA, compared with poor LTPA, was associated with better diastolic function [prevalence of normal diastolic function: 39.8% vs. 31.5%, P < 0.001; mean E/E' ratio (95% CI): 9.8 (9.6, 9.9) vs. 10.4 (10.2, 10.5), P = 0.001] and better systolic function [left-ventricular (LV) longitudinal strain: -18.3 (-18.4, -18.2) vs. -17.9 (-18.0, -17.8), P < 0.001] after adjusting for age, sex, race, and centre. Higher cumulative average LTPA over 24 years or an improvement in LTPA category were also, respectively, related to a more favourable E/E' ratio (P < 0.0001, P = 0.004) and longitudinal LV strain (P = 0.0002, P = 0.002).

CONCLUSION

Ideal LTPA, higher average levels of LTPA over a 24-year period, and an improvement in LTPA even later in life were associated with more favourable indices of LV diastolic and systolic function in older adults. Sustaining higher levels of LTPA, and even increasing physical activity later in life, may be beneficial for older adults in attenuating expected age-related changes in cardiac structure and function.

Do Physical Activity Patterns Across the Lifecourse Impact Birth Outcomes?

The significant impact of physical activity during, or immediately prior to pregnancy on a range of pregnancy and birth outcomes has been established. However, lifecourse theory posits that the antecedents of poor outcomes occur across a larger trajectory of time. The objective of this study was to examine whether physical activity patterns over the lifecourse impact birth outcomes. The sample (n = 1,713) was derived from Waves I, III, and IV of the National Longitudinal Study of Adolescent Health and limited to women who had their first, singleton live birth between Waves III and IV; respondents who had missing data were excluded. Outcome variables included preterm birth (<37 weeks) and low birth weight (<5.5 pounds). Physical activity was categorized as follows: long-term physically active (active at Waves I and III); short-term physically active (active at only Wave I or III); and not physically active (not active at Waves I and III). Survey-weighted logistic regression controlled for socio-demographic and established predictors of poor birth outcomes. Women categorized as long-term physically active had lower rates of preterm births (12.2 vs. 18.7 %) and low birth weight (9.1 vs. 11.1 %) compared to women categorized as not physically active. However, when controlling for covariates, adjusted analysis revealed that physical activity consistency only predicted preterm birth (aOR = 0.55, 95 % CI = 0.33-0.91). Findings suggest that physical activity patterns across the lifecourse may decrease risk of preterm birth. Implications include efforts supporting patterns of physical activity over longer periods of time prior to pregnancy.

Influence of Physical Activity on Hypertension and Cardiac Structure and Function

The global burden of hypertension is rising and accounts for substantial morbidity and mortality. Lifestyle factors such as diet and physical inactivity contribute to this burden, further highlighting the need for prevention efforts to curb this public health epidemic. Regular physical activity is associated with lower blood pressure, reduced cardiovascular risk, and cardiac remodeling. While exercise and hypertension can both be associated with the development of left ventricular hypertrophy (LVH), the cardiac remodeling from hypertension is pathologic with an associated increase in myocyte hypertrophy, fibrosis, and risk of heart failure and mortality, whereas LVH in athletes is generally non-pathologic and lacks the fibrosis seen in hypertension. In hypertensive patients, physical activity has been associated with paradoxical regression or prevention of LVH, suggesting a mechanism by which exercise can benefit hypertensive patients. Further studies are needed to better understand the mechanisms underlying the benefits of physical activity in the hypertensive heart.

Evidence for distinct effects of exercise in different cardiac hypertrophic disorders

Aerobic exercise training (AET) attenuates or reverses pathological cardiac remodeling after insults such as chronic hypertension and myocardial infarction. The phenotype of the pathologically hypertrophied heart depends on the insult; therefore, it is likely that distinct types of pathological hypertrophy require different exercise regimens. However, the mechanisms by which AET improves the structure and function of the pathologically hypertrophied heart are not well understood, and exercise research uses highly inconsistent exercise regimens in diverse patient populations. There is a clear need for systematic research to identify precise exercise prescriptions for different conditions of pathological hypertrophy. Therefore, this review synthesizes existing evidence for the distinct mechanisms by which AET benefits the heart in different pathological hypertrophy conditions, suggests strategic exercise prescriptions for these conditions, and highlights areas for future research.

Regular physical activity is associated with improved small artery distensibility in young to middle-age stage 1 hypertensives

The aim of the present study was to investigate the association of physical activity with small artery elasticity in the early stage of hypertension. We examined 366 young-to-middle-age stage 1 hypertensives (mean blood pressure 145.6±10.3/92.5±5.8 mmHg), divided into two categories of physical activity, sedentary (n=264) and non-sedentary (n=102) subjects. The augmentation index was measured using the Specaway DAT System. Small artery compliance (C2) was measured by applanation tonometry, at the radial artery, with an HDI CR2000 device. After 6 years of follow-up, arterial distensibility assessment was repeated in 151 subjects. Heart rate was lower in active than in sedentary subjects (71.2±8.9 vs 76.6±9.7 bpm, p<0.001). After adjusting for age, sex, heart rate, smoking, and blood pressure, C2 was higher (8.0±2.6 vs 6.4±3.0 ml/mmHg × 100, p=0.008) in non-sedentary than in sedentary patients. The augmentation index was smaller in the former (8.8±20.1 vs 16.8±26.5%, p=0.044) but the difference lost statistical significance after further adjustment for blood pressure. After 6 years, C2 was still higher in the non-sedentary than sedentary subjects. In addition, an improvement in the augmentation index accompanied by a decline in total peripheral resistance was found in the former. These data show that regular physical activity is associated with improved small artery elasticity in the early phase of hypertension. This association persists over time and is independent of blood pressure and heart rate.

Exercise training in adverse cardiac remodeling

Cardiac remodeling in response to a myocardial infarction or chronic pressure-overload is an independent risk factor for the development of heart failure. In contrast, cardiac remodeling produced by regular physical exercise is associated with a decreased risk for heart failure. There is evidence that exercise training has a beneficial effect on disease progression and survival in patients with cardiac remodeling and dysfunction, but concern has also been expressed that exercise training may aggravate pathological remodeling and dysfunction. Here we present studies from our laboratory into the effects of exercise training on pathological cardiac remodeling and dysfunction in mice. The results indicate that even in the presence of a large infarct, exercise training exerts beneficial effects on the heart. These effects were mimicked in part by endothelial nitric oxide synthase (eNOS) overexpression and abrogated by eNOS deficiency, demonstrating the importance of nitric oxide signaling in mediating the cardiac effects of exercise. Exercise prior to a myocardial infarction was also cardioprotective. In contrast, exercise tended to aggravate pathological cardiac remodeling and dysfunction in the setting of pressure-overload produced by an aortic stenosis. These observations emphasize the critical importance of the underlying pathological stimulus for cardiac hypertrophy and remodeling, in determining the effects of exercise training. Future studies are needed to define the influence of exercise type, intensity and duration in different models and severities of pathological cardiac remodeling. Together such studies will aid in optimizing the therapy of exercise training in the setting of cardiovascular disease.

Prevalence, awareness and risk factors of hypertension in a large cohort of Iranian adult population

BACKGROUND

There is considerable variation in hypertension prevalence and awareness, and their correlates, across different geographic locations and ethnic groups. We performed this cross-sectional analysis on data from the Golestan Cohort Study (GCS).

METHODS

Enrollment in this study occurred in 2004-2008, and included 50,045 healthy individuals from Golestan Province in northeastern Iran. Hypertension was defined as a SBP at least 140 mmHg, a DBP at least 90 mmHg, a prior diagnosis of hypertension, or the use of antihypertensive drugs. Potential correlates of hypertension and its awareness were analyzed by logistic regression adjusted for sex, age, BMI, place of residence, literacy, ethnicity, physical activity, smoking, black and green tea consumption and wealth score.

RESULTS

Of the total cohort participants, 21,350 (42.7%) were hypertensive. Age-standardized prevalence of hypertension, using the 2001 WHO standard world population, was 41.8% (95% confidence interval: 38.3-45.2%). Hypertension was directly associated with female sex, increased BMI, Turkmen ethnicity, and lack of physical activity, and inversely associated with drinking black tea and wealth score. Among hypertensive patients, 46.2% were aware of their disease, 17.6% were receiving antihypertensive medication, and 32.1% of the treated patients had controlled hypertension. Hypertension awareness was greater among women, the elderly, overweight and obese patients, and those with a higher wealth score.

CONCLUSION

Hypertension is highly prevalent in rural Iran, many of the affected individuals are unaware of their disease, and the rate of control by antihypertensive medications is low. Increasing hypertension awareness and access to health services, especially among less privileged residents are recommended.

Premenopausal women have increased risk of hypertensive target organ damage compared with men of similar age

BACKGROUND

The impact of high blood pressure (BP) on target organs (TO) in premenopausal women is not well known. The purpose of this study was to describe gender differences in TO involvement in a cohort of young-to-middle-aged subjects screened for stage 1 hypertension and followed for 8.2 years.

METHODS

Participants were 175 women and 451 men with similar age (range 18-45 years). Ambulatory BP at entry was 127.5±12.5/83.7±7.2 mm Hg in women and 131.9±10.3/81.0±7.9 mm Hg in men. Ambulatory BP, albumin excretion rate (AER), and echocardiographic data (n=489) were obtained at entry, every 5 years, and before starting antihypertensive treatment.

RESULTS

Female gender was an independent predictor of final AER (p=0.01) and left ventricular mass index (LVMI) (p<0.001). At follow-up end, both microalbuminuria (13.7% vs. 6.2%, p=0.002) and left ventricular hypertrophy (LVH) (26.4% vs. 8.8%, p<0.0001) were more common among women than men. In a multivariable Cox analysis, after adjusting for age, lifestyle factors, body mass, ambulatory BP, heart rate, and parental hypertension, female gender was a significant predictor of time to development of microalbuminuria (p=0.002), with a hazard ratio (HR) of 3.06, (95% confidence interval [CI] 1.48-6.34) and of LVH (p=0.004), with an HR of 2.50 (1.33-4.70). Inclusion of systolic and diastolic BP changes over time in the models only marginally affected these associations, with HRs of 3.13 (1.50-6.55) and 3.43 (1.75-6.70), respectively.

CONCLUSIONS

These data indicate that premenopausal women have an increased risk of hypertensive TO damage (TOD) and raise the question about whether early antihypertensive treatment should be considered in these patients.

Exercise training does not improve cardiac function in compensated or decompensated left ventricular hypertrophy induced by aortic stenosis

There is ample evidence that regular exercise exerts beneficial effects on left ventricular (LV) hypertrophy, remodeling and dysfunction produced by ischemic heart disease or systemic hypertension. In contrast, the effects of exercise on pathological LV hypertrophy and dysfunction produced by LV outflow obstruction have not been studied to date. Consequently, we evaluated the effects of 8 weeks of voluntary wheel running in mice (which mitigates post-infarct LV dysfunction) on LV hypertrophy and dysfunction produced by mild (mTAC) and severe (sTAC) transverse aortic constriction. mTAC produced ~40% LV hypertrophy and increased myocardial expression of hypertrophy marker genes but did not affect LV function, SERCA2a protein levels, apoptosis or capillary density. Exercise had no effect on global LV hypertrophy and function in mTAC but increased interstitial collagen, and ANP expression. sTAC produced ~80% LV hypertrophy and further increased ANP expression and interstitial fibrosis and, in contrast with mTAC, also produced LV dilation, systolic as well as diastolic dysfunction, pulmonary congestion, apoptosis and capillary rarefaction and decreased SERCA2a and ryanodine receptor (RyR) protein levels. LV diastolic dysfunction was likely aggravated by elevated passive isometric force and Ca(2+)-sensitivity of myofilaments. Exercise training failed to mitigate the sTAC-induced LV hypertrophy and capillary rarefaction or the decreases in SERCA2a and RyR. Exercise attenuated the sTAC-induced increase in passive isometric force but did not affect myofilament Ca(2+)-sensitivity and tended to aggravate interstitial fibrosis. In conclusion, exercise had no effect on LV function in compensated and decompensated cardiac hypertrophy produced by LV outflow obstruction, suggesting that the effect of exercise on pathologic LV hypertrophy and dysfunction depends critically on the underlying cause.

The mechanisms linking health literacy to behavior and health status

OBJECTIVE

To examine the mechanisms linking health literacy to physical activity and self-reported health.

METHODS

From 2005-2007, patients (N = 330) with hypertension were recruited from safety net clinics. Pathanalytic models tested the pathways linking health literacy to physical activity and self-reported health.

RESULTS

There were significant paths from health literacy to knowledge (r = 0.22, P < 0.001), knowledge to self-efficacy (r = 0.13, P < 0.01), self-efficacy to physical activity (r = 0.17, P < 0.01), and physical activity to health status (r = 0.17, P < 0.01).

CONCLUSIONS

Health education interventions should be literacy sensitive and aim to enhance patient health knowledge and self-efficacy to promote self-care behavior and desirable health outcomes.

Elevated heart rate in cardiovascular diseases: a target for treatment?

Heart rate is a major determinant of myocardial oxygen consumption and of cardiac work, and thus reduction of heart rate may represent an important strategy for the treatment of patients with a wide range of cardiac disorders. In addition, several experimental lines of research point to high heart rate as an important risk factor for atherosclerosis and, thus, pharmacologic heart rate reduction could prevent or retard the development of atherosclerotic plaques and increase survival. Today, in patients with acute or chronic coronary syndromes or with congestive heart failure, reducing heart rate is a generally accepted treatment modality. Up to now, no human study has been performed to demonstrate the efficacy and the risk-benefit ratio of cardiac slowing in patients without cardiac disorders. However, recent retrospective analyses of the INternational VErapamil-SR/trandolapril STudy and the Paris Prospective Study 1 provided promising results. Treatment of high heart rate in healthy subjects appears to be premature, but in clinical conditions such as hypertension or diabetes, the reduction of elevated heart rate appears a desirable additional goal of therapy.