Effects of exercise training on heart rate variability in individuals with lower extremity arterial disease and claudication: A systematic review.

PURPOSE: To perform a systematic review of studies assessing the effects of regular exercise on heart rate variability (HRV) in individuals with lower extremity arterial disease (LEAD) and symptoms of claudication. METHODS: A systematic search in the electronic databases MEDLINE, Embase, and Scielo, was conducted and updated on January 21, 2023. Randomized clinical trials investigating patients with LEAD and IC, assessing ≥ 4 wk of exercise interventions, and reporting at least one HRV measure (e.g., time or frequency domains) at baseline and follow-up were included. Two reviewers independently screened studies for inclusion, performed data extraction, and quality assessment of included studies. RESULTS: Data from 7 trials were included (i.e., 5 walking, 1 resistance, and 1 isometric handgrip training), totaling 327 patients (66% males; range: 61 - 68 yr; ankle brachial index: 0.4 - 0.7). Following exercise training, three studies investigating walking training reported an increase in parasympathetic modulation indices and/or a decrease in sympathetic modulation indices (n = 2) as well as an increase in non-linear indices (n = 1). CONCLUSION: The current evidence is weak, and larger randomized controlled trials are needed to confirm the efficacy of exercise training in improving HRV. Additionally, the high divergence in the methodology of studies indicated the need for standard tools to improve the quality of HRV measurements in exercise trials. It is recommended to use standard procedures in future trials investigating HRV.

Discriminating Metabolic Health Status in a Cohort of Nursing Students: Protocol for a Cross-Sectional Study.

BACKGROUND: Obesity is currently a worldwide health crisis. Nurses are integral members of the primary health care team and have an important role in managing obesity and administering physical activity (PA) for patients. However, research shows that nurses tend to be overweight or obese, have poor metabolic health, and do not meet PA recommendations. This is problematic because PA is linked to both physiological and psychological well-being and may also influence how nurses counsel their patients. Nursing students are the next generation of nurses; however, there is limited research examining PA (among other lifestyle factors) and metabolic health in nursing students. OBJECTIVE: The goal of this research is to examine multiple lifestyle factors (including PA, nutrition, sleep, and stress) and determine whether these factors are associated with metabolic health in full-time undergraduate nursing students. METHODS: An estimated 320 nursing students (18 years of age and older) will be assessed for their metabolic health. Metabolic status will be determined by measuring body mass index (BMI), waist-to-hip ratio (WHR), body fat percentage [skinfold measures (FitSystems Inc)], resting blood pressure [automated oscillatory (Omron Healthcare Inc)], and fasting blood glucose (glucometer). Lifestyle factors will also be measured, including PA and sleep [the International Physical Activity Questionnaire (IPAQ) and 7-day accelerometry (wGT3X-BT, Actigraph LLC)], nutrition [3-day diet log (Nutritionist Pro, Axxya Systems)], and stress [the Depression Anxiety Stress Scale, heart rate variability assessments, and salivary cortisol (ELISA, Eagle Biosciences)]. The association between metabolic status and PA, sleep quantity and quality, nutrition, and stress will be examined by linear regression analyses. Differences by year of study in metabolic health status, PA, sleep, nutrition, and stress will be examined by 1-way analyses of variance (ANOVAs). To determine the ability of PA, sleep, nutrition, and stress to discriminate prevalent overweight and obesity or poor metabolic status, logistic regression and receiver operating characteristic (ROC) curves will be constructed. Statistical analyses will be performed in Stata (version 16.1, StataCorp LLC). RESULTS: Based on pilot data, we believe senior nursing students will have worse metabolic health (ie, higher BMI and WHR, increased body fat percentage, higher blood pressure, and increased fasting blood glucose) compared to first-year students. We hypothesize that poor PA participation, poor sleep quantity and quality, increased food intake, poor nutrition, and increased stress will be associated with worse metabolic health in full-time nursing students. The study received funding in February 2020. Due to the coronavirus disease 2019 (COVID-19) pandemic, work on this study has been delayed. We are currently completing our application for institutional research ethics approval. Data collection is projected to begin in January 2021, with data collection and analyses expected to be completed by May 2022. CONCLUSIONS: This study will be the first published research to examine the relationship between lifestyle choices and metabolic status in nursing students attending a Canadian institution. More importantly, the results of this study will support the development of an informed intervention that will target the identified lifestyle factors, improving the physiological and mental health and well-being of nursing students. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/21342.

Low-Intensity Exercise Training Increases Heart Rate Variability in Patients With Peripheral Artery Disease.

Patients with peripheral artery disease (PAD), consistent with others with atherosclerotic occlusive disorders, have autonomic dysfunction (as measured by low heart rate variability [HRV]) that predisposes them to sympathetically mediated cardiac arrhythmias and sudden death. Exercise therapy has been shown to increase HRV in patients with coronary artery disease by increasing parasympathetic modulation of heart rate. This study quantified the circulatory and autonomic effects of a progressive, 12-week home-based, low-intensity (pain-free walking) exercise program in PAD and intermittent claudication. Participants (N = 33, mean age 67.8 8.1 years) were randomly assigned to either a walking group (n = 18), whose members performed a structured, 12-week, progressive walking program 5 days/week for 12 weeks, or a comparison group (n = 15), whose members performed usual activities. Circulatory measures (heart rate, blood pressure, and rate pressure product) and autonomic measures (HRV) were obtained at the beginning (Week 1) and end (Week 12) of the study. Minimal change in circulatory measures occurred. However, spectral analysis of HRV revealed that autonomic function improved significantly in members of the walking group; specifically, there was an increase in parasympathetic and a decrease in sympathetic modulation. Members of the walking group also significantly increased maximal walking distance. These findings suggest that a structured, low-intensity, high-frequency walking program improves autonomic function by increasing HRV in patients with PAD.

Exercise interventions for patients with peripheral arterial disease: a review of the literature.

Peripheral arterial disease (PAD) is a common chronic cardiovascular condition that affects the lower extremities and can substantially limit daily activities and quality of life. Lifestyle interventions, including smoking cessation, diet modification, regular physical activity, and pharmacotherapy, are often prescribed to treat patients with PAD. Exercise interventions can be effective in increasing claudication onset time and maximal walking distance. Of the various types of exercise interventions available for patients with PAD, little is known about the differences that may exist between men and women in patient response to such interventions. The purpose of this literature review is to examine the current knowledge of exercise interventions for individuals with mild (Fontaine stages I-II) PAD and to consider any differences that may exist between men and women. Women with PAD present with a different clinical profile compared with men, but respond similarly to an acute bout of exercise and a training program. Patients with PAD should be encouraged to walk regularly; however, more research is needed to determine differences between men and women in their response to various exercise interventions.

Depressive symptoms before and after elective hysterectomy.

OBJECTIVE: To examine the factors associated with depressive symptoms before and after surgery in women who undergo elective hysterectomy. DESIGN: A secondary analysis of longitudinal data from a prospective cohort study designed to understand chronic postsurgical pain in women. SETTING: One acute care hospital in southeastern, Ontario, over a 4-year period (2006-2010). PARTICIPANTS: Three hundred eighty-four (384) English-speaking women, age 18 years or older, who presented for elective hysterectomies. METHODS: Data were gathered preoperatively in the same-day admission center and six months postoperatively using validated web-based or mailed questionnaires. RESULTS: Thirty six percent (36%) of participants reported depressive symptoms before surgery, 22% reported symptoms afterwards, 15% reported symptoms at both time points, and 6% developed new onset depressive symptoms postoperatively. Younger (odds ratio [OR] = 2.5, 95% confidence interval [CI], [1.7, 5.0]) women, those with higher levels of anxiety (state: OR = 8.6, 95% CI [5.2, 14.0]), or who experienced pain that interfered with their daily functioning (OR = 2.8, 95% CI [1.7, 4.7]) were more likely to report depressive symptoms prior to hysterectomy. Preoperative pain (OR = 2.0, 95% CI [1.1, 3.6]), trait anxiety (OR = 2.4, 95% CI [1.2, 4.6]), and depressive symptoms (OR = 3.9, 95% CI [2.1, 7.5]) increased the risk of depressive symptoms 6 months postoperatively. CONCLUSION: Young women who exhibit high levels of anxiety and pain and who require a hysterectomy are at risk of experiencing psychological distress prior to and following their surgery.

Exercise performance by hemodialysis patients: a review of the literature.

Hemodialysis (HD) patients exhibit poor functional capacity and reduced quality of life as a result of the complications associated with end-stage renal disease (ESRD). A review of the literature indicates that regular physical activity can reduce the complications associated with ESRD by inducing adaptations in the cardiovascular, nervous, and musculoskeletal systems. In turn, this increases functional capacity and enhances quality of life in patients on HD. Hemodialysis patients can safely participate in a variety of exercise programs with minimal adverse effects. Intradialytic exercise programs that can incorporate aerobic and resistance exercise promote exercise adherence and should be encouraged on dialysis units.

Effects of passive exercise training on physical and psychological variables of elderly participants living in long-term care: a cross sectional study.

The frail elderly often exhibit a lack of physical activity that is associated with a decline in physical functioning and an inability to carry out activities of daily living. This can result in a greater demand on nursing care. Little is known about the minimal amount of exercise required to maintain or improve functional capacity in the frail elderly. This study explored the efficacy of passive exercise training for frail elderly residents in long-term care. Thirteen participants, aged 74-99 years, completed the study. Using a cross-sectional design, subjects were divided into three groups according to their activity pattern (a sedentary-control group [SED], a restorative care exercise group [RCE] and a passive exercise training group [PE]) and were monitored for 6 months. Participants in the SED group (n=5) performed normal daily activities whereas clients in the RCE group (n=4) were involved in a restorative care program. The PE group (n=4) performed continuous passive exercise, 2 days per week, using an "Ex N' Flex" machine. Anthropometric measurements, functional and psychological measures were obtained at the beginning and end of the study. At the end of training, participants in the PE group had a significant increase in resting body temperature. Moreover, participation in passive exercise tended to improve leg muscle strength and mobility. These results demonstrate that passive exercise training may help to maintain functional capacity in the frail elderly and improve circulation. This in turn will help the patient maintain their independence and ability to carry out activities of daily living and place less demand on nursing staff.

Weekly energy expenditure and quality of life in hemodialysis patients.

This study examined the relationship between physical activity patterns and quality of life among hemodialysis patients. While undergoing hemodialysis, 19 patients (31-82 years; 60.2 +/- 17.4 yrs, mean +/- SD) completed a physical activity and the Short-Form 36 (SF-36) questionnaire. Individuals were separated into either a high- or low-energy expenditure group. The high-energy expenditure group had significantly higher total SF-36 scores (58.35 +/- 4.49 vs. 42.85 +/- 3.86, mean +/- SE, p = 0.028) and physical functioning scores (62.22 +/- 8.00 vs. 27.14 +/- 3.16, mean +/- SE, p = 0.002) compared to individuals in the low-energy expenditure group. Members in the high-energy group tended to score higher on social functioning, general health, and role limitations. Increasing weekly energy expenditure, either through physical activity or household tasks, may increase quality of life and overall level of physical functioning in patients with end stage renal disease.

Effects of three different types of exercise on blood leukocyte count during and following exercise.

CONTEXT: High-intensity exercise causes tissue damage, production of stress hormones, and alterations in the function and quantity of various immune cells. Many clinical-physical stressors such as surgery, trauma, burns and sepsis induce a pattern of hormonal and immunological response similar to that of exercise. It has thus been suggested that heavy exercise might be used to cause graded and well-defined amounts of muscle trauma, thereby serving as an experimental model for inflammation and sepsis. OBJECTIVE: In order to explore whether some form of strenuous exercise might provide an useful model for the inflammatory process, we studied the effects of three different exercise protocols on blood leukocyte count during and following exercise. DESIGN: Four different experimental conditions, using a randomized-block design. SETTING: Defence and Civil Institute of Environmental Medicine, North York, Ontario, Canada. PARTICIPANTS: Eight healthy and moderately fit males. PROCEDURES: Participants were each assigned to four experimental conditions. Subjects performed 5 minutes of cycle-ergometry exercise at 90%, 2 hours of cycle-ergometry exercise at 60%, a standard circuit of resistance exercises with 3 sets of 10 repetitions at 60 to 70% of one-repetition maximum (1-RM) force at each of 5 different stations; or they remained seated for 5 hours. DIAGNOSTIC TEST USED: Flow cytometric analysis. MAIN MEASUREMENTS: Blood samples were analyzed for total leukocyte counts, total T cells, T helper/inducer cells, T suppressor/cytotoxic cells, B cells, cytolytic T cells, and natural killer cells. RESULTS: The peak aerobic and prolonged submaximal exercise induced similar alterations in cell counts. These changes were generally larger than those produced by the resistance exercise, although both resistance and peak aerobic exercise resulted in a significantly longer-lasting decrease in the CD4+/CD8+ ratio than the submaximal exercise bout did. CONCLUSION: The data suggest that, of the three exercise patterns tested, prolonged aerobic exercise induced the largest and most readily measured patterns of immune response. Nevertheless, the changes provided only a partial model for the clinical inflammatory process.

Effects of three different types of exercise on blood leukocyte count during and following exercise

CONTEXT: High-intensity exercise causes tissue damage, production of stress hormones, and alterations in the function and quantity of various immune cells. Many clinical-physical stressors such as surgery, trauma, burns and sepsis induce a pattern of hormonal and immunological response similar to that of exercise. It has thus been suggested that heavy exercise might be used to cause graded and well-defined amounts of muscle trauma, thereby serving as an experimental model for inflammation and sepsis. OBJECTIVE: In order to explore whether some form of strenuous exercise might provide an useful model for the inflammatory process, we studied the effects of three different exercise protocols on blood leukocyte count during and following exercise. DESIGN: Four different experimental conditions, using a randomized-block design. SETTING: Defence and Civil Institute of Environmental Medicine, North York, Ontario, Canada. PARTICIPANTS: Eight healthy and moderately fit males. PROCEDURES: Participants were each assigned to four experimental conditions. Subjects performed 5 minutes of cycle-ergometry exercise at 90 percent, 2 hours of cycle-ergometry exercise at 60 percent, a standard circuit of resistance exercises with 3 sets of 10 repetitions at 60 to 70 percent of one-repetition maximum (1-RM) force at each of 5 different stations; or they remained seated for 5 hours. DIAGNOSTIC TEST USED: Flow cytometric analysis. MAIN MEASUREMENTS: Blood samples were analyzed for total leukocyte counts, total T cells, T helper/inducer cells, T suppressor/cytotoxic cells, B cells, cytolytic T cells, and natural killer cells. RESULTS: The peak aerobic and prolonged submaximal exercise induced similar alterations in cell counts. These changes were generally larger than those produced by the resistance exercise, although both resistance and peak aerobic exercise resulted in a significantly longer-lasting decrease in the CD4+/CD8+ ratio than the submaximal exercise bout did. CONCLUSION: The data suggest that, of the three exercise patterns tested, prolonged aerobic exercise induced the largest and most readily measured patterns of immune response. Nevertheless, the changes provided only a partial model for the clinical inflammatory process

Cold exposure: human immune responses and intracellular cytokine expression.

It is commonly believed that exposure to cold environmental temperatures depresses immune function and increases the risk for infection. This review paper will 1) present an overview of human physiological responses to cold exposure, 2) present the human studies examining the effects of cold exposure on immune responses, and 3) summarize recent experiments from our laboratories examining the effects of exercise and fatigue on immune responses during subsequent cold exposure. Based on the review of the literature, there is no support for the concept that cold exposure depresses immune function.