Investigating how oxygen levels affect blood flow in the brain based on sex

Human Cerebral Blood Flow Regulation: Sex, Mechanism, and Stress Differences

This study is testing how oxygen levels affect blood flow in the brain differently for men and women in healthy young adults.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 18 Years to 40 Years
• Sex: All
• Sponsor: University of Wisconsin, Madison (other)
• Locations: 1 site (Madison, Wisconsin)
• Trial ID: NCT05958303 on ClinicalTrials.gov

What this trial studies

This study aims to explore the influence of biological sex on cerebral blood flow (CBF) regulation during hyperoxia in healthy young adults. A total of 30 participants, equally divided by sex and aged between 18 and 40, will undergo two MRI visits where they will experience both normoxia and hyperoxia conditions. The study will utilize an acute oral antioxidant cocktail in a double-blind, placebo-controlled design to assess the role of reactive oxygen species (ROS) in CBF control. The research will focus on whether men exhibit greater vasoconstrictor responses to hyperoxia and if there are regional differences in brain responses based on sex.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy young adults aged 18 to 40, with an equal representation of males and females.

Not a fit: Patients with a history of cardiovascular or metabolic diseases, hypertension, or other specified health conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance our understanding of sex-specific mechanisms in cerebrovascular health, potentially leading to improved treatments for cerebrovascular disorders.

How similar studies have performed: While the specific focus on sex differences in CBF regulation during hyperoxia is novel, related studies on ROS and cerebrovascular responses have shown promising results.

Eligibility criteria

Inclusion Criteria:

* Age between ≥18 - ≤40 years

Exclusion Criteria:

* Hypertensive

  * \>125 mmHg systolic blood pressure; or
  * \>80 mmHg diastolic blood pressure
* BMI ≥25 kg/m2
* Fasting blood glucose ≥100 mg/dl
* LDL cholesterol ≥130 mg/dl
* Triglycerides ≥150 mg/dl
* Current diagnosis or history of:

  * peripheral vascular disease
  * hepatic disease
  * renal disease
  * lung disease
  * gastrointestinal disorders/bleeding
  * hematologic disease
  * stroke
  * myocardial infarction
  * coronary heart disease
  * congestive heart failure
  * heart surgery
  * prediabetes
  * diabetes mellitus (type 1, type 2, MODY, or others)
  * sleep apnea
  * hypertension
  * some autoimmune diseases, such as inflammatory bowel disease or systemic lupus erythematosus (exclusion at discretion of reviewing MD)
* Current smoking, defined as the use of tobacco or nicotine products \>5 times in the past 30 days.
* Cardiovascular medication use
* NSAID sensitivity
* Any contraindications of having an MRI

  o (e.g. the requirement of anxiolytics in order to complete an MRI scan)
* Irregular menstrual cycle (females only)
* Medical conditions that can affect the menstrual cycle, such as hyperprolactinemia, prolactinoma, hypercortisolemia, and congenital adrenal hyperplasia (females only)
* Pregnancy, breast feeding, or plans to conceive within the next 3 months (females only)
* Polycystic ovary syndrome (females only)
* Hirsutism defined as unwanted and/or excessive hair growth on the face, chest, or back (females only)
* Levonorgestrel intrauterine device (IUD) (females only)
* Hormonal birth control will not be allowed in women, in order to control for high variability between type, dose, and route of therapy. However, in discussion with Dr. Davis (Co-I) and Dr. Laura Cooney M.D., physician experts in medical and reproductive endocrinology and infertility, there are two broad exceptions to this birth control criteria:

  1. Copper intrauterine devices (IUDs) will be allowed as they do not change systemic sex hormone levels).
  2. Women currently taking hormonal birth control (i.e. contraceptive pills, patch, ring) for contraception only (not for a medical condition such as those listed in exclusion criteria above) may consider temporarily stopping to become eligible for enrollment. Hormonal birth control must be stopped at least one month prior to Study Visit 1 to provide time for menstruation to resume. Then stoppage continues through the last planned study visit. Screening information will be reviewed by endocrinology physicians to determine eligibility and timing on this issue (details below).

Where this trial is running

Madison, Wisconsin

• University of Wisconsin — Madison, Wisconsin, United States (RECRUITING)

Study contacts

• Principal investigator: William G Schrage, PhD — University of Wisconsin, Madison
• Study coordinator: Shawn Bolin, MS

Conditions: Cerebrovascular Disorders