The Galway Sea Swimmers Study

Hypertension Clinical Trial

— GS3  

Official title:

The Galway Sea Swimmers Study: A Randomized Study of the Effect of Cold-Water Sea Swimming on Cardiovascular Risk Factors

Clinical Trial Details — Status: Suspended

Administrative data

• NCT number: NCT04290637
• Other study ID #: C.A. 2327
• Status: Suspended
• Phase: N/A
• Start date: October 2020
• Est. completion date: October 2021

Study information

• Verified date: April 2020
• Source: National University of Ireland, Galway, Ireland
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Suspended
• Enrollment: 150
• Est. completion date: October 2021
• Est. primary completion date: July 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 100 Years

Eligibility

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

Related Conditions & MeSH terms

• Cardiovascular Diseases
• Hypertension

Intervention

Other:
• Cold-water sea swimming
Continue sea swimming for 4-6 weeks
• No cold-water sea swimming
Discontinue sea swimming for 4-6 weeks

Locations

Country	Name	City	State
Ireland	Croi Heart and Stroke Centre	Galway

Sponsors (1)

Lead Sponsor	Collaborator
National University of Ireland, Galway, Ireland

Country where clinical trial is conducted

Ireland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Change in Sleep quality	Measured using Pittsburgh Sleep Quality Index. Values between 0 and 21, higher score indicates worse sleep quality	Administered at baseline and 6 weeks
Other	Change in Muscular strength	Measured using Hand grip dynamometer	Measured at baseline and 6 weeks
Primary	Change in mean systolic blood pressure	Systolic blood pressure recorded using a 24-hour ambulatory blood pressure monitor	Measured at baseline and again at 6 weeks
Secondary	Change in Pulse Wave Velocity	Pulse wave velocity measured using Complior Device	Measured at baseline and 6 weeks
Secondary	Change in Augmentation index	Augmentation index measured using Complior device	Measured at baseline and 6 weeks
Secondary	Change in Heart rate variability	Measured using 24-hour ambulatory blood pressure monitor	Measured at baseline and 6 weeks
Secondary	Change in Health-related quality of life	Measure using EQ-VAS (visual analog scale) instrument. Values between 0 (worst imaginable health) and 100 (best imaginable health)	Administered at baseline and 6 weeks
Secondary	Change in mean diastolic blood pressure	Diastolic blood pressure recorded using a 24-hour ambulatory blood pressure monitor	Measured at baseline and again at 6 weeks