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Abstract
Introduction Hypertension is a major risk factor for cardiovascular diseases. In 2015, over 1.13 billion individuals worldwide had hypertension. Globally, it results in 10.8 million deaths every year. Around half of the individuals do not continue treatment with medicine to control blood pressure. Physical activity, a non-pharmacological option of treatment, reduces blood pressure. We aim in this research to examine the effect of leisure-time physical activity in controlling blood pressure.
Methods and analysis We will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to conduct this study. We will perform a systematic search in Medline/PubMed, Embase, Scopus, Web of Science, Physical Education Index (ProQuest) and CENTRAL (the Cochrane Library). Both experimental and observational studies will be included. The study population would be people with hypertension. Two reviewers will perform screening of the articles, bias assessment and data extraction independently. We will use the Joanna Briggs Institute Critical Appraisal Tools to assess the risk of bias. We will conduct a meta-analysis if it is applicable.
Ethics and dissemination The results will be published in peer-reviewed journals and presented at relevant scientific seminars and conferences. Ethical approval is not applicable.
PROSPERO registration number CRD42021260751.
- hypertension
- epidemiology
- preventive medicine
- public health
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Strengths and limitations of this study
This systematic review will be the first study to synthesise the effects of leisure-time physical activity in controlling blood pressure.
The study will employ a rigorous search strategy following the gold standard methodology for systematic review, Preferred Reporting Items for Systematic Reviews and Meta-analysis.
Inclusion and exclusion criteria have been defined to identify all relevant articles regarding the effects of leisure-time physical activity in regulating blood pressure.
Literature on the English language will only be included in this study which may cause language bias.
Introduction
Hypertension or elevated blood pressure is a growing global public health concern and is considered a ‘silent killer’.1 Around 1.13 billion people were living with hypertension in 2015 globally.2 By 2025, the world will have 1.60 billion people with hypertension.3 Hypertension causes clinical and preclinical damage to vital organs, including the brain, heart and kidney.4 It resulted in 10.8 million fatalities globally in 2019,5 with 88% of death occurring in low-income and middle-income countries (LMICs).6 Reducing every 10 mm Hg systolic blood pressure and 5 mm Hg diastolic pressure decreases cardiovascular event by around a quarter and stroke by around a third.7
Several pharmacological and non-pharmacological treatments are available to manage people with hypertension. Changes in lifestyle, such as regular physical activity and food habits, are considered as the standard and primary treatment for controlling hypertension.8 9 Because non-pharmaceutical interventions such as physical activity, low intake of salt, smoking cessation, lower alcohol drinking and maintaining normal body weight are considered as the cost-effective alternative to control hypertension,10–12 whereas postmedication complications and treatment costs may adversely lead to the continuum of medication care of hypertension, particularly in LMICs.13–15 American College of Cardiology and American Heart Association also recommended newly diagnosed hypertension with a lower blood pressure threshold can be managed with lifestyle antihypertensive therapy rather than medicines.16
Control of hypertension is considered a pathfinder for universal health coverage.17 Therefore, one of the global targets for non-communicable diseases is to reduce the prevalence of hypertension by 25% by 2025 compared with 2010.1 Recent empirical epidemiological studies have demonstrated the association between leisure-time physical activity and the control of hypertension.18–21 Further, various recent experimental evidence from interventional studies have confirmed the association between regular physical exercise and controlling hypertension.22–27 Despite the available evidence, there is a dearth of systematic review and meta-analysis as supporting solid evidence on the role for physical activity in controlling high blood pressure integrated and summarised the effects of leisure-time physical activity comprising the epidemiological studies and interventional evidence although such studies are vital for informing policies. Thus, we aim to investigate the effects of leisure-time physical activities in controlling high blood pressure. The study will focus on leisure-time physical activities over other forms of physical activities as knowledge in this domain that is easily translatable to public health messages.
Methods
We will conform to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to conduct this study.28 The study started in July 2021, and the estimated completion date is February 2022.
Study design
We will include both experimental and observational studies. We will also include all studies conducted at any period.
Study population
We will include only those studies in which the age of the study population was 18 or above 18 years old. The study population would be patients living with hypertension (controlled or uncontrolled hypertension). We will not limit study participants based on nationality, residency (urban or rural), sex, ethnicity, regions and socioeconomic status.29
Study intervention
Interventions of the selected studies will examine the effect of leisure-time physical activity to control hypertension. We will include studies describing any leisure-time physical activities.
Comparators
Comparators will be control arms that do not perform any physical activities in leisure time, manage hypertension with any other non-pharmacological or pharmacological interventions.
Outcomes
The primary outcome will be a reduction of blood pressure. We will assess the outcome of interest from the reported level of blood pressure, systolic or diastolic, or both in selected articles. Secondary outcomes will be obesity indices such as body mass index, waist circumference and waist-hip ratio.
Inclusion criteria
We will include studies based on the study design, study population, interventions, comparators and outcomes described above.
Exclusion criteria
We will exclude any reviews, systematic reviews, review of reviews, protocols of trial. We will also exclude finding from books, chapters, comments, perspectives, editorials, letters, correspondences, conference proceedings and opinions. Age of study population less than 18 will be excluded. Moreover, we will exclude unpublished studies and preprints. If any studies are conducted to measure the effect of physical activity to control hypertension, only finding described effect of leisure-time physical activity will be included. If the finding of leisure-time physical activity does not describe separately, the study will be excluded. Studies carried out to examine the effect of leisure-time physical activity to prevent hypertension will also be excluded.
Search strategy
A comprehensive search will be carried out in electronic bibliographic databases including Medline/PubMed, Embase, Scopus, Web of Science, Physical Education Index (ProQuest) and CENTRAL (the Cochrane Library). We have developed a search strategy for all the above-mentioned databases. We used subject heading terms and keywords related to inclusion and exclusion criteria. Table 1 shows the search strategy for PubMed. Search strategy for the other databases has been added as online supplemental file. Further searches for eligible studies will be conducted by reviewing references within identified articles, relevant review or systematic review articles, relevant journals and different organisational websites. However, the corresponding author will be contacted if required data are not presented, or information is unclear, or full-text articles are not available for any study.
Supplemental material
Search strategy for PubMed/Medline
Studies selection
After retrieving articles, we will import all articles into Rayyan, an open-source software for undertaking screening in systematic reviews. Duplicate articles will be removed. Primarily, two reviewers will screen titles and abstracts independently. The qualified articles will be selected for full-text assessment. At this stage, another set of two reviewers will carry out the full-text review independently for final selection. At any stage, if a disagreement arises, a third reviewer will resolve it through consultation. Figure 1 shows the process of study selection adopted from the PRISMA 2020 statement.28
Process of systematic review.28
Data extraction
A data extraction form will be designed and pilot tested before tabulating the data. Two reviewers will extract data independently from the selected studies in a prespecified format. After completing data extraction, both reviewers will critically check data consistency. If any disagreement arises, the two reviewers will dissolve through discussion. The extracted data will have the details about the publication, study design, study population, intervention method in intervention and control arms in case of intervention studies, outcomes variables (mean/percentage, SD, ORs, RRs and 95% CIs). The threshold of leisure-time physical activity will be reported as per the included articles. The corresponding authors will be requested for the missing data.
Assessment of risk of bias
Two reviewers of the team will independently assess the methodological quality of the selected studies. Reviewers will assess the risk of bias of the selected studies using the Joanna Briggs Institute (JBI) Critical Appraisal Tools as a guide.30 JBI has separate critical appraisal tools for RCTs, quasi-experimental, cohort, cross-sectional and case–control studies. We will use specific critical appraisal tools of JBI for specific study designs of selected articles. The studies will then be evaluated as follows: low risk of bias (all items with low risk of bias), high risk of bias (at least one item with the high risk of bias) and uncertain risk of bias (at least one item marked as unclear). A third member will be responsible for addressing any differences that emerged during the risk assessment’s interpretation and quality assessment. Furthermore, disagreements between raters will be resolved through discussion.
Data synthesis
We will perform a meta-analysis to integrate the effect of leisure-time physical activity on R V.4.0 software if data of selected studies permit. We will conduct a meta-analysis if the study design, type of physical activity and reporting outcome variable are similar. A separate meta-analysis will be conducted for RCT and observational studies. We will conduct a dose-response meta-analysis if the finding of dose-response of included studies is available. The outcome measurements (OR, risk ratio, mean difference) will be reported as mentioned in the included articles. We will conduct I2 statistics to determine the heterogeneity of selected studies. We will perform a random effect model meta-analysis to examine the combined effect size if I2 ≤50%.31 If we find an I2 value higher than 50%, we will carry out subgroups analysis in this case as main factors may cause heterogeneity such as age, type of study, type of intervention, type of physical activity, settings, status/severity of hypertension. We will also perform a narrative synthesis of the results. Egger’s test will also be used to investigate publication bias. For dichotomous data, the measure of effect size will be reported as point risk ratios, ORs with 95% CIs. The measure effect size for continuous data will be reported in mean with SD.
Grading of evidence
The grading of evidence will be graded by two reviewers independently. We will follow the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to assess the grading of evidence.32 It will be based on the risk of bias, heterogeneity, indirectness, impression of findings and publications bias. The quality of evidence will be rated as high quality, moderate, low and very low quality, following GRADE guidelines. If there are any disagreements even after discussion among the two reviewers, a third reviewer will resolve through discussion.
Patient and public involvement
Patients or the public were not involved in the design, or conduct, or reporting, or dissemination plans of our research.
Discussion
Hypertension is one of the leading causes of poor health status from high-income to low-income countries.33 It is evident that controlling high blood pressure decreases the incidence of non-communicable diseases like stroke, heart failure and chronic kidney diseases.7 34 To control hypertension, several pharmacological and non-pharmacological interventions are used. However, the expected outcome is yet to bring in a significant level due to some barriers like treatment adherence, the resistance of drugs, out-of-pocket expenditure.35 On the other hand, it is well documented that physical activity improves health outcomes.36–38 In the case of controlling hypertension, physical activity has a good potential to reduce the blood pressure level among adults.9 A recent study depicted that half of the adults in the united adults have hypertension and leisure-time physical activity can improve the health condition though little is known about the level of the impact of this.39 However, no specific systematic review is found that concentrates on the effect of leisure-time physical activity to control hypertension.
Considering the importance of the issue and the limitation of the significant evidence, this study investigates how leisure-time physical activity can be an effective measure to control growing hypertension. The study poses some potential significance and implications that contribute to taking the evidence-based policy formulation by the decision-makers to deal with hypertension. The study will help researchers to use the findings and recommendations for further research. To disseminate the findings of this research among policymakers, physicians and public health researchers, we will use a wider arena such as journals, seminars, social media and daily newspapers.
This study does not limit to geography, residency and study period to include relevant studies in this review. A rigorous search strategy will be followed where meta-analysis will be carried out. These criteria help to improve the study synthesis. However, published articles based on the English language would be included, which is the only limitation of this protocol. This study does not include other language articles.
Ethics and dissemination
The findings will be disseminated in peer-reviewed journals and presented at scientific seminars and conferences relevant to the field. Individual patient information is not used. We do not need ethical approval to conduct this study.
Ethics statements
Patient consent for publication
Acknowledgments
The authors would like to acknowledge the contribution of the current donors providing unrestricted support to icddr,b that include: the Governments of Bangladesh, Canada, Sweden and the UK. We gratefully acknowledge these donors for their support and commitment to icddr,b’s research efforts.
References
Supplementary materials
Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Footnotes
Contributors KMS-U-R and MSI conceptualised the study, MGR and KMS-U-R contributed to the methodology section, MGR and MSI developed a search strategy. MSI, AF, MIS and MGR drafted the protocol. KMS-U-R critically reviewed and finalised the manuscript. KMS-U-R is the guarantor of the systematic review. All authors approved the publication of the protocol.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.