Clinical trial NCT06602921: The Effects of Nitrate, Caffeine, and Cold Exposure on Cardiovascular Function.
Official title: Does Dietary Nitrate Supplementation Attenuate the Cardiovascular Strain Elicited by Caffeine and Cold Exposure in Healthy Individuals?
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Nitrate
Caffeine
Cold Exposure
Keywords: Cardiovascular Function
Flow mediated dilation
Lead sponsor: Loughborough University
Sponsor class: OTHER
Collaborators: name: Biogen Extracts Pvt Ltd
First posted: 2024-09-19
Enrollment: 24
Sex: ALL
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: 24 participants will complete 4 experimental conditions in a randomized order.
Primary purpose: PREVENTION

Brief summary: Dietary inorganic nitrate supplementation may have positive implications on cardiovascular function. The aim of this project is to determine if nitrate supplementation can attenuate the effects that caffeine and cold exposure have on the cardiovascular system.

Detailed description: Acute caffeine consumption and cold exposure elicit negative effects on the cardiovascular system. Humans are regularly exposed to such conditions of increased cardiovascular strain, which may lead to elevated chronic cardiovascular risk. On the other hand, dietary inorganic nitrate supplementation is well established to improve cardiovascular function in healthy individuals. Thus, acute nitrate supplementation may compensate for the negative effects that caffeine and the cold place on the cardiovascular system. These effects will be measured using peripheral blood pressure, pulse wave analysis, heart rate variability, forearm blood flow, flow mediated dilation, and blood and saliva markers.

Eligibility criteria: Inclusion Criteria:

* Blood pressure \< 130 mmHg systolic and \< 85 mmHg diastolic. BMI between 18.5 and 29.9 kg/m2. Females must be naturally menstruating (regular length cycle and menses) or using a form of combined hormonal contraception (for at least 6 months).

Exclusion Criteria:

* Existing cardiovascular or metabolic conditions. Experience any adverse reactions to experimental procedures or supplements. Allergies to supplements or breakfast items. Involved in any other studies. Blood pressure \> 130 mmHg systolic and \> 85 mmHg diastolic.

Primary outcomes:
measure: Brachial blood pressure
timeFrame: Mean of 5 readings taken pre-supplementation (0 hours) and post-supplementation (2.5 hours). 1 reading was taken pre- cold pressor test (3.5 hours). All measures were recorded on every experimental trial (4 trials with at least 48 h washout between).
measure: Flow mediated dilation
timeFrame: Measured pre-supplementation (at 0 hours) and post-supplementation (at 2.5 hours) for every experimental trial (4 trials with at least 48 h washout between).
measure: Central blood pressure and pulse wave variables
timeFrame: Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and during the cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).
Secondary outcomes:
measure: Forearm blood flow
timeFrame: Measured pre-supplementation (at 0 hours) and post-supplementation (at 2.5 hours) for every experimental trial (4 trials with at least 48 h washout between).
measure: Salivary nitrate and nitrite
timeFrame: Measured pre-supplementation (at 0 hours) and post-supplementation (at 2.5 hours) for every experimental trial (4 trials with at least 48 h washout between).
measure: Heart rate variability
timeFrame: Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and during the cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).
measure: NIBP continuous blood pressure
timeFrame: Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and during the cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).
measure: Whole blood RSNO
timeFrame: Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and immediately post- cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between).
measure: Plasma nitrate, nitrite, cGMP
timeFrame: Collected pre-supplementation (0 hours), post-supplementation (2.5 hours), and immediately post- cold pressor test (3.5 h) for 4 experimental trials (4 trials with at least 48 hours washout in between)
Other outcomes:
Locations:
city: Loughborough
country: United Kingdom
facility: Loughborough University
Study officials:
affiliation: Loughborough University
name: Stephen Bailey
role: PRINCIPAL_INVESTIGATOR
References: