Sam Liu

Interval and continuous exercise elicit equivalent postexercise hypotension in prehypertensive men, despite differences in regulation

Equicaloric bouts of interval (IE: 5 × 2:2 min at 85% and 40% maximal oxygen uptake) and steady state (SS: 21 min at 60% maximal oxygen uptake) exercise were performed by 13 older prehypertensive males on separate days, at equivalent times of day, to assess the influence of exercise mode on postexercise hypotension (PEH). Exercise conditions were compared with a control session. Cardiovascular measures were collected for 30 min prior to, and 60 min following exercise. PEH, as measured by mean postexercise systolic blood pressure (SBP) decrease (IE: -4 ± 6 mm Hg; SS: -3 ± 4 mm Hg; control: 4 ± 4 mm Hg), area under the SBP curve (IE: -240 ± 353 mm Hg·min; SS: -192 ± 244 mm Hg·min), and minimum SBP achieved (IE: -15 ± 7 mm Hg; SS: -13 ± 7 mm Hg), was equivalent after both conditions. Stroke volume was significantly reduced (IE: -14.6 ± 16.0 mL; SS: -10.1 ± 14.2 mL, control -1.7 ± 2.2 mL) and heart rate was significantly elevated (IE: 13 ± 8 beats·min⁻¹; SS: 7.9 ± 8 beats·min⁻¹; control: -2 ± 3 beats·min⁻¹) postexercise after both conditions. Cardiac output and total peripheral resistance were nonsignificantly decreased and increased postexercise, respectively. Baroreflex sensitivity (BRS) was reduced following IE (p < 0.05) and heart rate variability (HRV) parameters were reduced after both conditions, with IE eliciting larger and longer reductions in some indices. The results from the current study indicate that older prehypertensive adults experience similar PEH following equicaloric bouts of IE and SS exercise despite larger alterations in HRV and BRS elicited by IE.

Blood pressure reduction following prolonged exercise in young and middle-aged endurance athletes

Background: Previous studies examining the relationship between exercise dose and post-exercise hypotension (PEH) have employed a limited range of exercise duration and subject age. We extended the dose–response curve by studying two intensities of prolonged exercise that may produce a greater magnitude of PEH and reveal age differences in the exercise dose–response relationship for PEH. Methods: Two groups of healthy recreational endurance athletes were studied: Young (n = 17; age 28 ± 1.1 years) and middle-aged participants (n = 18; 52 ± 0.90 years). They performed on separate occasions, 120 min of prolonged exercise (running) at moderate (60% VO2max) and high intensities (80% VO2max). Results: PEH after 1 hour of recovery was similar within each age group for either exercise intensity, but was significantly greater in the middle-aged group (moderate intensity, −12.3 ± 1.6 mmHg; high intensity, −15.1 ± 1.7 mmHg) compared with the young group (moderate intensity, −1.2 ± 1.7 mmHg; high intensity, −5.7 ± 2.5 mmHg; p < 0.05). Stepwise regression showed that baseline blood pressure but not age was significantly related to the degree of PEH. Thus, the greater PEH seen in the middle-aged group is attributed to their higher baseline blood pressure (124 ± 3.0/79 ± 2.0 mmHg) than the young group (111 ± 2.0/69 ± 1.8 mmHg). A reduced total peripheral resistance following exercise was the primary contributor to PEH across both age groups and exercise intensities. Conclusions: We conclude that prolonged exercise induces a significant PEH regardless of exercise intensity.

Reducing risk with e-based support for adherence to lifestyle change in hypertension (REACH): protocol for a multicentred randomised controlled trial

Introduction Web-based lifestyle counselling designed to improve adherence to self-management behaviours for diet, exercise and medication has been shown to reduce blood pressure (BP). However, the long-term clinical outcome of these interventions is not established. Our aim was to establish whether an e-counselling program is independently associated with improved clinical outcomes over a 12-month period, as defined by the following criteria: (1) reduction of systolic BP, diastolic BP, pulse pressure and associated risk factors for cardiovascular events; and (2) adherence to self-management behaviour (diet, exercise, smoke-free living and prescribed medication). Methods and analysis Reducing risk with e-based support for adherence to lifestyle change in hypertension is a two-parallel group, double-blind randomised controlled trial that will utilise a two (Groups: e-counselling vs control) by three (assessment intervals: baseline, 4-month and 12-month outcome) design. BP, lipoprotein cholesterol, physical activity and dietary behaviours and psychological distress will be measured at each assessment. We plan to recruit 528 participants (35–74 years of age) diagnosed with stage 1 or 2 hypertension (systolic BP, 140–180 mm Hg; diastolic BP 90–110 mm Hg) from three major cities (Toronto, London, Vancouver) and one rural area (Grey Bruce region) across Canada between February 2012 and July 2015. Controls will receive general educational e-messages on heart healthy living and the e-counselling group will receive tailored e-messages that are matched to their stage of readiness for change. For both groups, e-messages will be sent proactively on a weekly basis during months 1–4, then bi-weekly during months 5–8 and then monthly during months 9–12. Ethics and dissemination Ethical approval has been obtained from all recruitment sites. This will be one of the first studies to evaluate the long-term efficacy of preventive e-counselling strategies for cardiovascular disease prevention in patients with hypertension. Findings from this study will be used to guide the ongoing development of e-counselling services. Trial Registration Clinicaltrial.gov NCT01541540; http://clinicaltrials.gov/ct2/show/NCT01541540.

An Internet-Based Counseling Intervention With Email Reminders that Promotes Self-Care in Adults With Chronic Heart Failure: Randomized Controlled Trial Protocol

Background Chronic heart failure (CHF) is a public health priority. Its age-standardized prevalence has increased over the past decade. A major challenge for the management of CHF is to promote long-term adherence to self-care behaviors without overtaxing available health care resources. Counseling by multidisciplinary health care teams helps to improve adherence to self-care behaviors and to reduce the rate of death and hospitalization. In the absence of intervention, adherence to self-care is below recommended standards. Objective This trial aims to establish and evaluate a Canadian e-platform that will provide a core, standardized protocol of behavioral counseling and education to facilitate long-term adherence to self-care among patients with CHF. Methods Canadian e-Platform to Promote Behavioral Self-Management in Chronic Heart Failure (CHF-CePPORT) is a multi-site, double blind, randomized controlled trial with a 2 parallel-group (e-Counseling + Usual Care vs e-Info Control + Usual Care) by 3 assessments (baseline, 4-, and 12-month) design. We will identify subjects with New York Heart Association Class II or III systolic heart failure from collaborating CHF clinics and then recruit them (n=278) by phone. Subjects will be randomized in blocks within each site (Toronto, Montreal, and Vancouver). The primary outcome will be improved quality of life, defined as an increased number of subjects with an improvement of ≥5 points on the summary score of the Kansas City Cardiomyopathy Questionnaire. We will also assess the following secondary outcomes: (1) diet habits, depression, anxiety, smoking history, stress level, and readiness for change using self-report questionnaires, (2) physical activity level, current smoking status, and vagal-heart rate modulation by physiological tests, and (3) exercise capacity, prognostic indicators of cardiovascular functioning, and medication adherence through medical chart review. The primary outcome will be analyzed using generalized estimation equations with repeated measures on an intention-to-treat basis. Secondary outcomes will be analyzed using repeated-measures linear mixed models with a random effects intercept. All significant main effects or interactions in the statistical models will be followed up with post hoc contrasts using a Bonferroni correction with a 2-sided statistical significance criterion of P<.05. Results This 3.5-year, proof-of-principle trial will establish the e-infrastructure for a pan-Canadian e-platform for CHF that is comprised of a standardized, evidence-based protocol of e-Counseling. Conclusions CHF-CePPORT is designed to improve long-term adherence to self-care behaviors and quality of life among patients with CHF. It will demonstrate a distinct Canadian initiative to build capacity for preventive eHealth services for patients with CHF. Trial Registration ClinicalTrials.gov NCT01864369; http://clinicaltrials.gov/ct2/show/NCT01864369 (Archived by WebCite at http://www.webcitation.org/6Iiv6so7E).

Lifesource XL-18 pedometer for measuring steps under controlled and free-living conditions

Abstract The primary aim was to examine the criterion and construct validity and test–retest reliability of the Lifesource XL-18 pedometer (A&D Medical, Toronto, ON, Canada) for measuring steps under controlled and free-living activities. The influence of body mass index, waist size and walking speed on the criterion validity of XL-18 was also explored. Forty adults (35–74 years) performed a 6-min walk test in the controlled condition, and the criterion validity of XL-18 was assessed by comparing it to steps counted manually. Thirty-five adults participated in the free-living condition and the construct validity of XL-18 was assessed by comparing it to Yamax SW-200 (YAMAX Health & Sports, Inc., San Antonio, TX, USA). During the controlled condition, XL-18 did not significantly differ from criterion (P > 0.05) and no systematic error was found using Bland–Altman analysis. The accuracy of XL-18 decreased with slower walking speed (P = 0.001). During the free-living condition, Bland–Altman analysis revealed that XL-18 overestimated daily steps by 327 ± 118 than Yamax (P = 0.004). However, the absolute percent error (APE) (6.5 ± 0.58%) was still within an acceptable range. XL-18 did not differ statistically between pant pockets. XL-18 is suitable for measuring steps in controlled and free-living conditions. However, caution may be required when interpreting the steps recorded under slower speeds and free-living conditions.

The Effectiveness of Loyalty Rewards to Promote the Use of an Internet-Based Heart Health Program

Background Internet-based health programs have been shown to be effective in reducing risk for cardiovascular disease. However, their rates of enrollment and engagement remain low. It is currently unclear whether rewards from established loyalty programs can serve as a conditioned stimulus to improve the use of a freely available Internet-based program. Objective The objectives of the study were to (1) examine enrollment rates and levels of engagement with the My Health eSupport program between a Conditioned Reward group and a Control group, and (2) investigate the influence of loyalty rewards and participant characteristics on levels of enrollment and program engagement. Methods The study sample (n=142,726) consisted of individuals who were offered enrollment in an Internet-based health intervention (My Health eSupport) after completing the Heart&Stroke Risk Assessment on the Heart and Stroke Foundation website. My Health eSupport programs provided encouragement and tips for lifestyle change. This is a free, self-guided, fully automated program that proactively delivers tailored email messages at 2-week intervals based on the participant’s stage of motivational “readiness” and priority for lifestyle change. Participants in the Conditioned Reward group were offered a single exposure of 20 loyalty reward points from the Air Miles loyalty program for completing the Heart&Stroke Risk Assessment (10 reward points) and enrolling in the Internet-based program (10 reward points). Meanwhile, no rewards were given to the Control group participants. All data were collected between February 1, 2011 and February 10, 2012. Results In total, 51.38% (73,327/142,726) of individuals in the Conditioned Reward group and 48.62% (69,399/142,726) of individuals in the Control group completed the Heart&Stroke Risk Assessment. Subsequently, significantly more individuals from the Conditioned Reward group (52.96%, 38,835/73,327) enrolled in the My Health eSupport program than Controls (4.07%, 2826/69,399). Regression analyses indicated that individuals were 27.9 times (95% CI 26.4-29.4; P<.001) more likely to join the My Health eSupport program when presented with loyalty rewards controlling for gender, age, education, ethnicity, employment, and number of modifiable risk factors. However, ongoing engagement level was low in both groups and it was not influenced by loyalty rewards. Instead, individuals were more likely to engage with the My Health eSupport program if they were greater than 60 years of age (OR 12.56, 95% CI 5.66-27.8; P<.001), were female (OR 1.27, 95% CI 1.09-1.46; P=.002), or had one or more modifiable risk factors (OR 1.38, 95% CI 1.31-1.45; P<.001). Conclusions Our findings suggest that a single exposure of loyalty rewards may be used to encourage individuals to enroll in an Internet-based preventative health program, but additional strategies are required to maintain engagement level. Future studies need to examine the schedules of loyalty reward reinforcement on the long-term engagement level of Internet-based health programs.

Usability Testing of an Internet-Based e-Counseling Platform for Adults With Chronic Heart Failure.

Background Chronic heart failure (CHF) is a major cause of hospitalization and mortality. In order to maintain heart function and quality of life, patients with CHF need to follow recommended self-care guidelines (ie, eating a heart healthy diet, exercising regularly, taking medications as prescribed, monitoring their symptoms, and living a smoke-free life). Yet, adherence to self-care is poor. We have developed an Internet-based e-Counseling platform, Canadian e-Platform to Promote Behavioral Self-Management in Chronic Heart Failure (CHF-CePPORT), that aims to improve self-care adherence and quality of life in people with CHF. Before assessing the efficacy of this e-platform in a multisite, double-blind, randomized controlled trial, we evaluated the usability of the prototype website. Objective The objective of the study was to assess the usability of the CHF-CePPORT e-Counseling platform in terms of navigation, content, and layout. Methods CHF patients were purposively sampled from the Heart Function Clinic at the Peter Munk Cardiac Center, University Health Network, to participate in this study. We asked the consented participants to perform specific tasks on the website. These tasks included watching self-help videos and reviewing content as directed. Their interactions with the website were captured using the “think aloud” protocol. After completing the tasks, research personnel conducted a semi-structured interview with each participant to assess their experience with the website. Content analysis of the transcripts from the “think aloud” sessions and the interviews was conducted to identify themes related to navigation, content, and layout of the website. Descriptive statistics were used to summarize the satisfaction data. Results A total of 7 men and women (ages 39-77) participated in 2 iterative rounds of testing. Overall, all participants were very satisfied with the content and layout of the website. They reported that the content was helpful to their management of CHF and that it reflected their experiences in coping with CHF. The layout was professional and friendly. The use of videos made the learning process entertaining. However, they experienced many navigation errors in the first round of testing. For example, some participants were not sure how to navigate across a series of Web pages. Based on the experiences that were reported in the first round, we made several changes to the navigation structure. This included using large navigation buttons to direct users to each section and providing tutorial videos to familiarize users with our website. We assessed whether these changes improved user navigation in the second round of testing. The major finding is that participants made fewer navigation errors and they did not identify any new problems. Conclusions We found evidence to support the usability of our CHF-CePPORT e-Counseling platform. Our findings highlight the importance of a clear and easy-to-follow navigation structure on user experience.

E-counseling as an emerging preventive strategy for hypertension.

Purpose of review Lifestyle counseling that includes exercise training, diet modification, and medication adherence is critical to hypertension management. This article summarizes the efficacy of lifestyle counseling interventions in face-to-face, telehealth, and e-counseling settings. It also discusses the therapeutic potential of e-counseling as a preventive strategy for hypertension. Recent findings The recent proliferation of telehealth and e-counseling programs increases the reach of preventive counseling for patients with cardiovascular disorders. Blood pressure reduction following these interventions is comparable to face-to-face interventions. However, the effectiveness of e-counseling varies depending on the design features of the core protocol. An evidence-based guideline needs to be established that identifies e-counseling components which are independently associated with blood pressure reduction. As the Internet becomes more sophisticated, e-counseling is demonstrating a therapeutic advantage in comparison with other telehealth interventions. Summary Current evidence supports further development of preventive e-counseling programs for hypertension. A pressing challenge for investigators is to specify key evidence-based components of e-counseling that are essential to the core protocol. In order to achieve this goal, it will be necessary to ensure that e-counseling programs are also clinically organized, in order to guide patients through the process of initiating and sustaining therapeutic behavior change.

Effectiveness of User- and Expert-Driven Web-based Hypertension Programs: an RCT

INTRODUCTION The effectiveness of self-guided Internet-based lifestyle counseling (e-counseling) varies, depending on treatment protocol. Two dominant procedures in e-counseling are expert- and user-driven. The influence of these procedures on hypertension management remains unclear. The objective was to assess whether blood pressure improved with expert-driven or user-driven e-counseling over control intervention in patients with hypertension over a 4-month period. STUDY DESIGN This study used a three-parallel group, double-blind randomized controlled design. SETTING/PARTICIPANTS In Toronto, Canada, 128 participants (aged 35-74 years) with hypertension were recruited. Participants were recruited using online and poster advertisements. Data collection took place between June 2012 and June 2014. Data were analyzed from October 2014 to December 2016. INTERVENTION Controls received a weekly e-mail newsletter regarding hypertension management. The expert-driven group was prescribed a weekly exercise and diet plan (e.g., increase 1,000 steps/day this week). The user-driven group received weekly e-mail, which allowed participants to choose their intervention goals (e.g., [1] feel more confident to change my lifestyle, or [2] self-help tips for exercise or a heart healthy diet). MAIN OUTCOME MEASURES Primary outcome was systolic blood pressure measured at baseline and 4-month follow-up. Secondary outcomes included cholesterol, 10-year Framingham cardiovascular risk, daily steps, and dietary habits. RESULTS Expert-driven groups showed a greater systolic blood pressure decrease than controls at follow-up (expert-driven versus control: -7.5 mmHg, 95% CI= -12.5, -2.6, p=0.01). Systolic blood pressure reduction did not significantly differ between user- and expert-driven. Expert-driven compared with controls also showed a significant improvement in pulse pressure, cholesterol, and Framingham risk score. The expert-driven intervention was significantly more effective than both user-driven and control groups in increasing daily steps and fruit intake. CONCLUSIONS It may be advisable to incorporate an expert-driven e-counseling protocol in order to accommodate participants with greater motivation to change their lifestyle behaviors, but more studies are needed. TRIAL REGISTRATION This study is registered at www.clinicaltrials.gov NCT03111836.