How artery-relaxing chemicals affect blood pressure after prolonged sitting
The Role of Endothelial-Derived Hyperpolarization Factors on 24-hr Blood Pressure Regulation Following a Bout of Prolonged Sitting
This trial tests whether giving a single dose of fluconazole to block artery-derived relaxing factors changes blood pressure over the next 24 hours after a long bout of sitting in healthy adults aged 18–65.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 40 (estimated) |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Sponsor | Université de Sherbrooke Academic / other |
| Locations | 1 site (Halifax, Nova Scotia) |
| Trial ID | NCT07396857 on ClinicalTrials.gov |
What this trial studies
Healthy volunteers will complete a prolonged uninterrupted sitting bout and receive either a single 150 mg dose of fluconazole or a placebo. Investigators will measure blood pressure and arterial function at sites affected by sitting (e.g., the popliteal artery) and at arteries supplying the brain (e.g., the carotid) and will monitor responses over the following 24 hours. The comparison between fluconazole and placebo arms is intended to reveal whether endothelial-derived hyperpolarizing factors (EDHF) contribute to immediate and carry-over blood pressure changes from sitting. Participants will be screened for health status, medications, and lifestyle exclusions and must attend in-person visits at Dalhousie University in Halifax.
Who should consider this trial
Good fit: Ideal candidates are non-smoking, normotensive adults age 18–65 with BMI under 40 kg/m2 who are not taking cardiovascular, metabolic, pulmonary, or interacting medications and who can attend in-person visits in Halifax, Nova Scotia.
Not a fit: People with diagnosed cardiovascular, cerebrovascular, respiratory, or metabolic disease, pregnant or breastfeeding people, regular smokers, those taking excluded medications (for example statins, NSAIDs, certain antidepressants), or those with BMI ≥40 are unlikely to qualify or receive benefit from this protocol.
Why it matters
Potential benefit: If successful, the trial could identify a specific arterial signaling mechanism to target for preventing blood pressure disturbances after prolonged sitting.
How similar studies have performed: Previous studies show uninterrupted sitting disrupts blood pressure and that EDHF contributes to local artery relaxation, but using fluconazole to probe 24-hour carry-over effects is a novel approach.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Are between the ages of 18-65. * Have a body mass index of \<40kg/m2 (non-obese). * Have not smoked nicotine or marijuana-containing products most days of the week within the past 6 months. * Have not been diagnosed with a cardiovascular, cerebrovascular, respiratory, or metabolic disease. * Are normotensive. * Are not currently taking any medications for cardiovascular, metabolic, pulmonary, or neurological disorders, or taking sildenafil regularly. * Are not allergic to the adhesive used to secure the activPAL activity monitors. * Are not pregnant or breastfeeding. * Are not regularly taking any of the following: another anti-fungal, heartburn medications containing cisapride (e.g., Propulsid), depression medications containing amitriptyline (e.g., Elavil) or nortriptyline (e.g., Pamelor), erythromycin (antibiotic), lipid lower medications (i.e., statins), non-steroidal anti-inflammatory drugs (e.g., ibuprofen), or vitamin A supplements. Exclusion Criteria: * o Younger than 18 years old. Individuals younger than 18 demonstrate more variable peak FMD responses and require multiple assessments to determine peak response. * Over the age of 65. There are age-related impacts on arterial function and the responses to sitting. * Body mass index of \>40 kg/m2 (i.e., obese II category)(6-8). * Smoked nicotine or marijuana-containing products most days of the week within the past 6 months. Cardiovascular health for participants who smoke is poor compared to those who do not smoke, which will negatively impact our arterial function outcomes. * Have been diagnosed with a cardiovascular, cerebrovascular, respiratory, or metabolic disease. Such conditions impact our assessments of arterial health. The results of unhealthy participants are not of interest in this study. * Hypertension (seated resting systolic pressure \>139 mmHg and/or diastolic pressure \>89 mmHg). Hypertensive individuals have impairments in artery health, which will affect their baseline artery health measures. * Hypotensive (seated resting systolic pressure \<90 mmHg and/or diastolic pressure \<60 mmHg). Hypotensive people are more likely to experience further reductions in blood pressure during the sitting protocol, which will increase the risk of fainting and/or dizziness. * Have a history of fainting and/or dizziness during sitting or standing. * Prescribed medications for cardiovascular, metabolic, pulmonary, or neurological disorders. This includes people using hormone replacement therapy. These medications will interfere with our assessments and interpretation of arterial health. * Have a known allergy to the clear medical adhesive used to secure the activPAL activity monitors. * Females who are pregnant or breastfeeding. Pregnant and breastfeeding females are ineligible to participate. This is due to the known increases in arterial vasodilation associated with pregnancy related sex hormones. * Currently or recently (within the past 6 months) regularly taking sildenafil or other medications that increase the relaxing effects of nitric oxide in arteries. Such medication will influence artery blood flow and flow-mediated dilation responses. * Are regularly taking any of the following: another anti-fungal, heartburn medications containing cisapride (e.g., Propulsid), depression medications containing amitriptyline (e.g., Elavil) or nortriptyline (e.g., Pamelor), erythromycin (antibiotic), lipid lower medications (i.e., statins), non-steroidal anti-inflammatory drugs (e.g., ibuprofen), or vitamin A supplements. These are to minimize the chance of a participant experiencing an adverse reaction to the fluconazole tablet.
Where this trial is running
Halifax, Nova Scotia
- Dalhousie University — Halifax, Nova Scotia, Canada (Recruiting)
Study contacts
- Principal investigator: Myles W O'Brien, PhD — Université de Sherbrooke
- Study coordinator: Molly K Courish, MSc, PhD(s)
- Email: molly.courish@dal.ca
- Phone: 902-818-0783
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.