Obesity, Healthy, Vasoconstriction, Vasodilation
Conditions
Brief summary
Patients with sleep apnea are at increased risk of developing cardiovascular disease - with women at potentially greater risk than men. Contributing mechanisms are not well understood, but may be related to how women respond to low oxygen and, given over 70% of patients with sleep apnea are obese, the impact of obesity. This project seeks to increase our understanding of mechanisms that may contribute to sex differences in the cardiovascular response to low oxygen with the hope that this knowledge will improve the efficacy of current therapies and support the discovery of novel therapeutics.
Interventions
OTHERHypoxia Exposure
Systemic oxygen levels will be titrated to attain hypoxemia as assessed by pulse oximetry.
DRUGPhenylephrine
Phenylephrine (0.0625 mcg/dL/min) will be locally infused via brachial artery catheter during the final 3 min of normoxia and hypoxia.
DRUGDexmedetomidine
Dexmedetomidine (12.5 ng/dL/min) will be locally infused via brachial artery catheter during the final 3 min of normoxia and hypoxia.
DRUGPhentolamine
Phentolamine will be locally infused via brachial artery catheter for 10 min before baseline measurement (12 mcg/dL/min) and the infusion will continue at a maintenance rate (5 mcg/dL/min) during acute normoxia and hypoxia.
DRUGNorepinephrine
Regional forearm infusion at 8 ng/dL/min via brachial artery catheter during normoxia and hypoxia exposures
Sponsors
University of Missouri-Columbia
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* 18-45 years of age (premenopausal) * Healthy weight (BMI ≥18 and ≤25 kg/m2) * Obese (BMI ≥30 kg/m2)
Exclusion criteria
* Pregnancy, breastfeeding, oral hormonal contraceptive use * Diagnosed sleep apnea or Oxygen desaturation index \>10 events/hr * Current smoking/Nicotine use * Increased risk of bleeding, pro-coagulant disorders, clotting disorders, anticoagulation therapy * Nerve/neurologic disease * Cardiovascular, hepatic, renal, respiratory disease * Blood pressure ≥140/90 mmHg * Diabetes, Polycystic ovarian syndrome * Communication barriers * Prescription medications, Sensitivity to lidocaine
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in forearm vascular conductance with intra-arterial drug infusion | Continuous measurement of vascular conductance during infusion of each drug (final 3 min of normoxia and hypoxia). | Vascular conductance is an index of vascular tone and is measured using a technique called venous occlusion plethysmography. |
Countries
United States
Outcome results
None listed