Sex Differences in Reflex Responses to Intermittent Hypoxia

The purpose of the present study is to determine whether there are sex differences in the reflex responses to hypoxia in humans.

Study Overview

• Status: Completed
• Conditions: Healthy Participants
• Intervention / Treatment: Other: Hypoxic exposure

Detailed Description

Over 35% of the US population will develop sleep apnea at some point in their life. Sleep apnea is the most common form of sleep disordered breathing and patients with sleep apnea are at increased risk of developing high blood pressure. Intermittent, repeated exposures to low oxygen during sleep (intermittent hypoxia, IH) has been implicated as the primary stimulus for increases in sympathetic nervous system activity and blood pressure with sleep apnea. Interestingly there are some reports of a lower incidence of hypertension in women with sleep apnea when compared to men. Results from the present study will provide information important to the investigator's understanding of potential sex-differences in clinical outcomes for conditions related to acute/chronic hypoxia and may have important implications for treatments which may improve blood pressure control in patients with sleep apnea.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Missouri
    • Columbia, Missouri, United States, 65211
      • University of Missouri-Columbia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• healthy adult men and women;
• BMI <30 kg/m2;
• non-pregnant;
• non-breastfeeding;
• non-smokers;
• premenopausal women with a normal menstrual cycle unaffected by hormonal contraceptive use;
• taking no medications known to affect autonomic or cardiovascular function (PI discretion).

Exclusion Criteria:

• taking any medications known to affect the cardiovascular or autonomic nervous system (e.g. alpha-blockers, beta-blockers, etc);
• a self-reported history of hepatic, renal, pulmonary, cardiovascular, or neurological diseases;
• stroke or neurovascular disease;
• bleeding/clotting disorder;
• sleep apnea or other sleep disorders;
• diabetes;
• smoking;
• history of alcoholism or substance abuse;
• hypertension.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Hypoxic Exposure; Men, and women in early or late follicular phase of menstrual cycle will be exposed to acute and intermittent hypoxic episodes.	Other: Hypoxic exposure; 30 minutes of intermittent hypoxia

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline Hypoxic Ventilatory Response after intermittent hypoxia	Hypoxia breathing will be recorded before and after intermittent hypoxia	Through completion of intermittent hypoxia, an average of 3 hours
Change from baseline Blood Pressure after intermittent hypoxia	Systolic and diastolic blood pressure will be recorded before and after intermittent hypoxia	Through completion of intermittent hypoxia, an average of 3 hours
Change from baseline Forearm Blood Flow after intermittent hypoxia	Blood flow in the forearm will be recorded before and after intermittent hypoxia	Through completion of intermittent hypoxia, an average of 3 hours

Collaborators and Investigators

• Sponsor: University of Missouri-Columbia
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: Jacqueline Limberg, PhD, University of Missouri-Columbia

Study record dates

Study Major Dates

• Study Start (Actual): September 13, 2018
• Primary Completion (Actual): July 15, 2021
• Study Completion (Actual): July 15, 2021

Study Registration Dates

• First Submitted: June 11, 2018
• First Submitted That Met QC Criteria: July 27, 2018
• First Posted (Actual): July 30, 2018

Study Record Updates

• Last Update Posted (Actual): July 21, 2021
• Last Update Submitted That Met QC Criteria: July 19, 2021
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Hypoxia
• Other Study ID Numbers: 2011312; 4R00HL130339 (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