EXERCISE AND BLOOD PRESSURE: APPLYING FINDINGS FROM THE LABORATORY TO THE COMMUNITY SETTING

Exercise training in patients with pulmonary and systemic hypertension: A unique therapy for two different diseases

Pulmonary hypertension is a potentially life-threatening condition. Given its evolving definition, the incidence and prevalence of the disease is difficult to define, but registries suggest an increased global awareness. The management of patients with pulmonary arterial hypertension is highly specialised and requires multi-disciplinary input from a range of healthcare professionals, including cardiologists, respiratory physicians, rheumatologists, rehabilitation physicians and cardio-pulmonary physiotherapists. Historically, exercise training in pulmonary hypertension has not been recommended because of safety concerns. However, an increasing number of studies have demonstrated the benefit of exercise training on exercise capacity, peak oxygen consumption and quality of life. Systemic hypertension is one of the most important risk factors for cardiovascular disease, and has been ranked as the leading cause for death and disability worldwide: therefore, adequate control of blood pressure is important for public health. Lowering of blood pressure and prevention of hypertension is in first instance preferable by lifestyle changes. These include weight loss, moderation of alcohol intake, a diet with increased fresh fruit and vegetables, reduced saturated fat, reduced salt intake, reduced stress, and, finally, increased physical activity. With regard to the latter, former guidelines predominantly recommended aerobic exercises such as walking, jogging, and cycling for lowering blood pressure. The main focus of this narrative overview paper is to briefly examine and summarize the benefit of exercise training in patients with pulmonary and systemic hypertension, suggest mechanisms by which exercise may improve symptoms and function and provide evidence-based recommendations regarding the frequency and intensity of exercise in these patients.

Acute and Chronic Exercise in Animal Models

Numerous animal cardiac exercise models using animal subjects have been established to uncover the cardiovascular physiological mechanism of exercise or to determine the effects of exercise on cardiovascular health and disease. In most cases, animal-based cardiovascular exercise modalities include treadmill running, swimming, and voluntary wheel running with a series of intensities, times, and durations. Those used animals include small rodents (e.g., mice and rats) and large animals (e.g., rabbits, dogs, goats, sheep, pigs, and horses). Depending on the research goal, each experimental protocol should also describe whether its respective exercise treatment can produce the anticipated acute or chronic cardiovascular adaptive response. In this chapter, we will briefly describe the most common kinds of animal models of acute and chronic cardiovascular exercises that are currently being conducted and are likely to be chosen in the near future. Strengths and weakness of animal-based cardiac exercise modalities are also discussed.

Examining Rowe and Kahn's Concept of Successful Aging: Importance of Taking a Life Course Perspective

PURPOSE OF THE STUDY

This article critiques Rowe and Kahn's conceptualization of successful aging using tenets of the life course perspective.

DESIGN AND METHODS

A review and synthesis of the literature on successful aging and studies that use a life course perspective.

RESULTS

We draw on life course principles that view development as a dynamic lifelong process, embedded in historical time and place, and influenced by the web of relationships individuals are linked to, as well as more distal social structural factors. This discussion questions the relatively static nature of Rowe and Kahn's successful aging model, its emphasis on personal control over one's later-life outcomes, and neglect of historical and cultural context, social relationships, and structural forces in influencing later-life functioning.

IMPLICATIONS

Caution in using the model in its current formulation is needed, and we promote thinking about how successful aging can better align with micro- and macrolevel issues through utilization of a life course perspective.

Humanized animal exercise model for clinical implication

Exercise and physical activity function as a patho-physiological process that can prevent, manage, and regulate numerous chronic conditions, including metabolic syndrome and age-related sarcopenia. Because of research ethics and technical difficulties in humans, exercise models using animals are requisite for the future development of exercise mimetics to treat such abnormalities. Moreover, the beneficial or adverse outcomes of a new regime or exercise intervention in the treatment of a specific condition should be tested prior to implementation in a clinical setting. In rodents, treadmill running (or swimming) and ladder climbing are widely used as aerobic and anaerobic exercise models, respectively. However, exercise models are not limited to these types. Indeed, there are no golden standard exercise modes or protocols for managing or improving health status since the types (aerobic vs. anaerobic), time (morning vs. evening), and duration (continuous vs. acute bouts) of exercise are the critical determinants for achieving expected beneficial effects. To provide insight into the understanding of exercise and exercise physiology, we have summarized current animal exercise models largely based on aerobic and anaerobic criteria. Additionally, specialized exercise models that have been developed for testing the effect of exercise on specific physiological conditions are presented. Finally, we provide suggestions and/or considerations for developing a new regime for an exercise model.

Decanoato de nandrolona aumenta a parede ventricular esquerda, mas atenua o aumento da cavidade provocado pelo treinamento de natação em ratos

Os esteroides anabólicos androgênicos (EAAs) são drogas sintetizadas a partir da testosterona. Sua ação anabólica deve-se principalmente ao aumento da síntese e redução na degradação das proteínas musculares. Este trabalho investiga os efeitos do treinamento de natação associado ao tratamento com decanoato de nandrolona sobre a pressão arterial, as dimensões cardíacas e reatividade vascular. Quarenta ratos Wistar machos, com idade de 60 dias, foram divididos em quatro grupos (n = 10): sedentário (SN), sedentário tratado (ST), treinados (TN) e treinados tratados (TT). Animais TN e TT realizaram um treinamento de natação durante 12 semanas, enquanto os animais ST e TT receberam decanoato de nandrolona semanalmente (15mg/kg). O coração e os testículos foram removidos e pesados. O diâmetro da cavidade do ventrículo esquerdo (DcVE) e a espessura da parede ventricular (EspVE) foram medidos com um paquímetro eletrônico. A pressão arterial sistólica (PAS) e a pressão arterial diastólica (PAD) foram medidas semanalmente; ainda, foi estudada a reatividade vascular das artérias mesentéricas em resposta à noradrenalina. Em nosso trabalho não houve alterações no peso do coração; no entanto, verificamos aumento no DcVE (p < 0,05) em ratos TN, enquanto a EspVE aumentou (p < 0,05) nos ratos ST e TT, ambos em relação ao SN. O peso do testículo diminuiu (p < 0,05) em ST e TT em relação a SN. Tanto a pressão arterial quanto a reatividade vascular não foram alteradas. Concluímos que o treinamento de natação aumentou o diâmetro da cavidade ventricular esquerda, enquanto o tratamento com decanoato de nandrolona aumentou a espessura da parede ventricular esquerda, sugerindo uma hipertrofia concêntrica

Bioenergetic provision of energy for muscular activity

A complex series of metabolic pathways are present in human muscle that break down substrates from nutritional sources to produce energy for different types of muscular activity. However, depending on the activity in which an individual is engaged, the body will make use of different energy systems that have been adapted for the particular activity. More specifically, utilization of bioenergetic substrates depends on the type, intensity, and duration of the exercise. The aerobic oxidative system is used for longer duration activities of low to moderate intensity, the anaerobic glycolytic system is used for short to moderate duration activities of higher intensity, and the high energy phosphagen system is used for short duration activities of high intensity. The efficiency and effectiveness of these pathways can be enhanced through physical activity and training. It is these bioenergetic pathways that are the focus of this review.

[Association between hypertension and pulmonary function in rural adults in Korea]

OBJECTIVES

Whilst hypertension exerts a negative effect on several organs there have been few studies regarding its effect on pulmonary function. The objective of this study was to examine the relationship between hypertension and pulmonary function in rural Korean adults.

METHODS

In 2006, 2534 people were recruited, aged 40 to 70, in Kangwha County. We selected 1454 (male: 624, female: 830) participants whose pulmonary function results were repeatable. Blood pressure (BP) was measured twice and the average calculated. Participants were divided into two groups (hypertensive group and non-hypertensive group) in accordance with The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Pulmonary function was measured by dry rolling seal spirometry. Forced expiratory volume in the one second and forced vital capacity were converted into percent-predicted values based on average pulmonary function amongst Koreans.

RESULTS

The number of hypertensive participants in the present study was 460 (male: 205, female: 255) and the number of non-hypertensive participants was 994 (male: 419, female: 575). Our findings have shown that the mean values for expiratory volume in the one second and forced vital capacity were significantly lower for hypertensive people than for non-hypertensive people, among women (P=0.002 for forced expiratory volume in the one second, P<0.001 for forced vital capacity volume). Odds ratio analysis revealed that hypertensive participants were more likely to have lower pulmonary function than non-hypertensive participants, again significantly among women.

CONCLUSIONS

The pulmonary function of hypertensive women was significantly lower than that of non-hypertensive women aged 40-70.

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.

The potential anti-inflammatory benefits of improving physical fitness in hypertension

Hypertension is associated with an increased risk of stroke and atherosclerosis. In addition to elevated blood pressure, hypertension is characterized by neuroendocrine and immune activation, including elevated levels of C-reactive protein, inflammatory cytokines, and soluble adhesion molecules, which are predictive of morbidity and mortality outcomes. Pharmacological treatment for hypertension reduces blood pressure, but has limited effectiveness in reducing the accompanying inflammation and its associated morbidity and mortality. Exercise and diet interventions regularly show reductions in blood pressure in hypertensive individuals. Similar interventions in other populations show reductions in many inflammatory markers, but these effects have not been routinely examined in hypertensive individuals. The mechanisms through which exercise might exert an anti-inflammatory action include the sympathetic nervous system, the hypothalamic-pituitary-adrenal axis, as well as direct effects of blood pressure. Here, exercise is promoted as a potentially effective treatment for both the elevated blood pressure and chronic inflammation found in hypertension.

Effects of walking exercise on nocturia in the elderly

We investigated whether nocturia in the elderly was improved by walking exercise, which involved walking rapidly for 30 min or more in the evening or night for 8 weeks. A questionnaire related to micturition and exercise, blood pressure, body composition analysis, blood biochemistry tests, and urinalysis were performed before and after 8 weeks of exercise to investigate the effects of walking. Thirty men (71 years old on average) continued the walking exercise for long enough to undergo evaluation. The number of episodes of nocturia decreased significantly (p < 0.001) from 3.3 +/- 0.7 to 1.9 +/- 0.8 after 8 weeks of walking exercise. The daytime urinary frequency, blood pressure, body weight, body fat ratio, edema ratio, serum catecholamines, triglycerides, and total cholesterol were also decreased. After 8 weeks of exercise, 20 of the subjects (67%) stated that sleep was deeper than before exercise. Assessment of the overall improvement showed that excellent or good results were obtained in 18 patients (60%). The main factor related to the influence of walking exercise on nocturia was that sleep became deeper, which increased the arousal threshold bladder volume. Walking exercise may also have a preventive effect on lifestyle-related diseases.