Sex Differences in Vascular Responses to Exercise

Sex Differences in Chronic and Acute Vascular Responses to Aerobic Exercise in Older Adults

A key early event in cardiovascular disease development is endothelial dysfunction, characterized by impaired flow-mediated dilation. Regular aerobic exercise ameliorates endothelial dysfunction in healthy older men, but the data in healthy postmenopausal women are inconsistent with many studies showing no effect. The primary objective of this study was to examine sex differences in acute and chronic endothelial responses to exercise training in older men vs. older postmenopausal women.

Study Overview

• Status: Completed
• Conditions: Aging
• Intervention / Treatment: Behavioral: Control Period; Behavioral: Exercise Period

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32611
      • Integrative Cardiovasculal Physiology Laboratory, University of Florida

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 56 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• adults able to give consent
• men and women
• women must be postmenopausal (either natural or surgical)
• 60 to 79 years of age

Exclusion Criteria:

• any relevant cardiovascular diseases (e.g., history of coronary artery bypass surgery or angioplasty, or heart failure, myocardial infarction, angina pectoris, peripheral arterial disease)
• myocardial ischemia during maximal graded exercise test
• major chronic clinical disease (e.g., diabetes, renal or hepatic disease or infection with hepatitis B, C, or HIV)
• seizures, or other relevant on-going or recurrent illness
• recent (within 3 months) or recurrent hospitalizations
• systolic blood pressure < 100 mmHg
• body mass index > 35 kg/m^2
• >5% weight change in past 3 months or unwilling to remain weight stable during study participation
• use of tobacco products including smoking traditional or e-cigarettes
• use of hormone replacement therapy in women or men (e.g., estrogen, progesterone or testosterone)
• regular aerobic exercise training (≥30 min/session and ≥ 3 days/week)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Older Men	Behavioral: Control Period; Participants completed an 8-week control period of normal lifestyle.; Behavioral: Exercise Period; Participants completed an 8-week exercise intervention period of remotely supervised home-based non-weight-bearing all-extremity high intensity interval training (NWA-HIIT). NWA-HIIT consisted of 4x4-min bouts at 90% of maximal heart rate (HRmax) interspersed by 3x3-min bouts at 70% of HRmax. A 10-min warm-up and 5-minute cool-down at 70% of HRmax were included.
Active Comparator: Older Postmenopausal Women	Behavioral: Control Period; Participants completed an 8-week control period of normal lifestyle.; Behavioral: Exercise Period; Participants completed an 8-week exercise intervention period of remotely supervised home-based non-weight-bearing all-extremity high intensity interval training (NWA-HIIT). NWA-HIIT consisted of 4x4-min bouts at 90% of maximal heart rate (HRmax) interspersed by 3x3-min bouts at 70% of HRmax. A 10-min warm-up and 5-minute cool-down at 70% of HRmax were included.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in FMD in Response to Chronic HIIT	Flow mediated dilation (FMD) is an established non-invasive measure of endothelial function. Brachial artery FMD was determined via ultrasonography in response to reactive hyperemia following 5-min forearm ischemia. FMD was expressed as % change and was calculated as (max diameter-baseline-diameter)/baseline diameter)*100. The change in FMD for the control period was calculated as the difference in FMD from baseline to the end of the 8-week control period. The change in FMD for the exercise intervention period was calculated as the difference in FMD from the end of the 8-week control period to the end of the 8-week intervention period.	From baseline to end of 8-week control period; From end of 8-week control period to end of 8-week exercise intervention
Change in FMD in Response to Acute HIIT in the Untrained State	Flow mediated dilation (FMD) is an established non-invasive measure of endothelial function. Brachial artery FMD was determined via ultrasonography in response to reactive hyperemia following 5-min forearm ischemia. FMD was expressed as % change and was calculated as (max diameter-baseline-diameter)/baseline diameter)*100. FMD was investigated at pre-exercise, at the end of a HIIT session, and 1-hour and 24-hours following a HIIT session in the untrained state (before beginning the 8-week exercise intervention consisting of HIIT). The change in FMD in response to acute HIIT was calculated 1) at the end of exercise (as the difference from pre-exercise to end of exercise); 2) 1-hour post-exercise (as the difference from pre-exercise to 1-hour post-exercise) and 3) 24-hours post-exercise (as the difference from pre-exercise to 24-hours post-exercise).	From pre-exercise to end of exercise; From pre-exercise to 1-hour post-exercise; From pre-exercise to 24-hours post-exercise
Change in FMD in Response to Acute HIIT in the Trained State	Flow mediated dilation (FMD) is an established non-invasive measure of endothelial function. Brachial artery FMD was determined via ultrasonography in response to reactive hyperemia following 5-min forearm ischemia. FMD was expressed as % change and was calculated as (max diameter-baseline-diameter)/baseline diameter)*100. FMD was investigated at pre-exercise, at the end of a HIIT session, and 1-hour and 24-hours following a HIIT session in the trained state (at the end of the 8-week exercise intervention consisting of HIIT). The change in FMD in response to acute HIIT was calculated 1) at the end of exercise (as the difference from pre-exercise to end of exercise); 2) 1-hour post-exercise (as the difference from pre-exercise to 1-hour post-exercise) and 3) 24-hours post-exercise (as the difference from pre-exercise to 24-hours post-exercise).	From pre-exercise to end of exercise; From pre-exercise to 1-hour post-exercise; From pre-exercise to 24-hours post-exercise
Correlation Coefficient for the Relationship Between Acute and Chronic FMD Response to HIIT		Acute FMD response at 1) pre-exercise vs. end of exercise; 2) pre-exercise vs. 1-hour post-exercise; and 3) pre-exercise vs. 24-hours post-exercise. Chronic FMD response at baseline vs. end of 8-week. exercise intervention

Collaborators and Investigators

• Sponsor: University of Florida
• Collaborators: National Institute on Aging (NIA)
• Investigators: Principal Investigator: Demetra Christou, PhD, University of Florida

Study record dates

Study Major Dates

• Study Start (Actual): November 22, 2019
• Primary Completion (Actual): May 31, 2023
• Study Completion (Actual): May 31, 2023

Study Registration Dates

• First Submitted: October 14, 2019
• First Submitted That Met QC Criteria: October 14, 2019
• First Posted (Actual): October 16, 2019

Study Record Updates

• Last Update Posted (Estimated): November 14, 2024
• Last Update Submitted That Met QC Criteria: October 23, 2024
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Keywords: Aerobic exercise; Acute exercise; High-Intensity Interval Training
• Other Study ID Numbers: IRB201902165- N; R21AG063143 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No