Cardiovascular Diseases, Hypertension
Conditions
Keywords
Cardiovascular Diseases, Cardiac Disease, Heart Diseases, Hypertension, Blood Pressure, Swimming, Exercise, Vascular Stiffness, Pulse Wave Analysis, Health-Related Quality Of Life, Heart Rate Variability, Immersion
Brief summary
Cardiovascular disease (CVD) is the leading cause of death worldwide. Hypertension is a well-established risk factor for the development of CVD. Lifestyle modifications, including exercise, remain the cornerstone of blood pressure (BP)-lowering strategy. Swimming has long been a popular recreational activity for exercise, and is recently gaining widespread recognition as an effective option in maintaining and improving cardiovascular health. Previous studies that involved pool swimming as an intervention (versus no pool swimming) demonstrated favorable benefits of the former on BP reduction. However, no studies to date have specifically investigated the effect of cold-water sea swimming on BP. Indeed, the naturally lower water temperature in the sea may engender a 'cold water immersion' experience in sea swimmers with subsequent stress physiology, which have been shown to exert unique effects on cardiovascular hemodynamics. This study primarily aims to determine the impact of cold-water sea swimming on BP in a group of habitual sea swimmers in Galway who will be randomly assigned to either continue or stop swimming for 4-6 weeks. Other objective and subjective health benefits to sea swimming will also be explored in this study. Given the ubiquitous nature of this activity in the Irish general public, particularly in Galway, this study has potential from a public health perspective, and would add to the literature base pertaining to the benefits of sea swimming on cardiovascular health.
Detailed description
Consenting participants will be randomly assigned, 1:1, to either continuation of sea swimming or discontinuation of sea swimming for 4-6 weeks, stratified by the type of swimmer (those who purely immerse in the water for a brief period of time versus those who actually swim \[i.e., exercise\] in the water) and use of blood pressure medication at the time of study commencement (yes or no), using a block size of four to maintain balance between intervention arms. In line with previous studies that assessed the impact of swimming intervention on BP, participants randomized to the swimming arm should pursue sea swimming 2 or more days/week.
Interventions
OTHERCold-water sea swimming
Continue sea swimming for 4-6 weeks
OTHERNo cold-water sea swimming
Discontinue sea swimming for 4-6 weeks
Sponsors
National University of Ireland, Galway, Ireland
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
Yes
Inclusion criteria
* habitual swimmers (i.e., sea swimming at least 2 times/week for the past year) * 18 years of age or older * able to provide informed consent
Exclusion criteria
* underlying cardiac (e.g., self-reported heart failure) or pulmonary diseases (e.g., self-reported chronic obstructive pulmonary disease) * recent orthopedic procedures (e.g., joint replacement therapy) * severe disabling comorbidity * recent arm (both arms) or chest wall injury * pregnant or breast feeding
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in mean systolic blood pressure | Measured at baseline and again at 6 weeks | Systolic blood pressure recorded using a 24-hour ambulatory blood pressure monitor |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Pulse Wave Velocity | Measured at baseline and 6 weeks | Pulse wave velocity measured using Complior Device |
| Change in Augmentation index | Measured at baseline and 6 weeks | Augmentation index measured using Complior device |
| Change in Heart rate variability | Measured at baseline and 6 weeks | Measured using 24-hour ambulatory blood pressure monitor |
| Change in Health-related quality of life | Administered at baseline and 6 weeks | Measure using EQ-VAS (visual analog scale) instrument. Values between 0 (worst imaginable health) and 100 (best imaginable health) |
| Change in mean diastolic blood pressure | Measured at baseline and again at 6 weeks | Diastolic blood pressure recorded using a 24-hour ambulatory blood pressure monitor |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change in Sleep quality | Administered at baseline and 6 weeks | Measured using Pittsburgh Sleep Quality Index. Values between 0 and 21, higher score indicates worse sleep quality |
| Change in Muscular strength | Measured at baseline and 6 weeks | Measured using Hand grip dynamometer |
Countries
Ireland
Outcome results
None listed