Combined Effects of Prolonged Sitting and Mental Stress on the Cardiovascular System

The Combined Effects of Prolonged Sitting and Mental Stress on Vascular and Cerebrovascular Function in Middle-Aged Adults

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04207333

Enrollment

Registered

2019-12-20

Start date

2020-01-11

Completion date

2020-06-01

Last updated

2023-04-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cardiovascular Risk Factor, Cerebrovascular Insufficiency, Cognitive Change, Mental Stress, Sedentary Behavior

Brief summary

Prolonged sitting may pose a public health risk through its effects on the cardiovascular system, and may lead to impaired whole-body cardiovascular health, which includes both vascular and cerebrovascular function. These effects may interact with other environmental variables, such as stress. However, no study has investigated the combined effect of a mental stressor and prolonged sitting on vascular and cerebrovascular function. The combined effect of prolonged sitting and mental stress may lead to an exacerbated effect on vascular, cerebrovascular, and executive function. The investigators hypothesize that mental stress with the addition of prolonged sitting \[PS\] will result in a greater increase in peripheral, central and cerebral arterial stiffness and elicit a decrease in cerebral perfusion, total blood flow to the brain, middle cerebral artery velocity and executive function, compared to mental stress without prolonged sitting \[CON\]. The findings from this study may result in a public health message regarding sedentary behavior and stress, and will help elucidate the mechanisms behind acute vascular, cerebrovascular, and cognitive dysfunction during prolonged sitting.

Detailed description

This study is a multi-visit (three in total) randomized crossover trial. During a single familiarization session, the research team will obtain informed consent, and will describe to participants the purposes and procedures of this study. They will then be exposed to all experimental devices on in a quiet, dimly lit and environmentally controlled room. Participants will return to the same location for two experimental conditions following these pre-assessment guidelines: * Fasted (\> 12 hours), consuming only water. * No caffeine consumption 12 hours prior to testing. * No vigorous exercise 24 hours prior to testing. * No alcohol consumption 24 hours prior to testing. Participants will arrive to the Applied Physiology Laboratory between 6:00 and 10:00 a.m. fasted (for Visit 3: 2-5 days following the Visit 2). Participants will be fasted and refrain from caffeine intake for at least 12 hours, and alcohol and strenuous physical activity for at least 24 hours prior to arrival. Upon arrival, height and weight will be recorded followed by 10 minutes of quiet rest in the supine position. During these 10 minutes, the subject will be fitted with a Near Infra-Red Spectroscopy probe on the prefrontal cortex and medial gastrocnemius. The non-invasive continuous blood pressure, transcranial doppler, and Vicorder arterial stiffness devices will also be affixed to the participant during this time period during this time. Sitting periods will begin for both conditions once all devices are attached to the participant, the subject is shifted to an upright seated position, and at least 10 minutes of supine rest has been recorded. During the control (CON) visit, subjects will undergo a brief 20 minute sitting period. For the prolonged sitting (PS) condition, subjects will be asked to sit still and quietly for 2 hours while watching a non-stimulating documentary. Each condition will receive the mental stress at the conclusion of the sitting periods in both CON and PS. After exposure to the mental stress in both conditions, data collection procedures for this protocol will be completed. Arterial stiffness measurements will be made immediately after the mental stress, and then every 5 minutes, up to 30 minutes. Brain blood flow will be assessed by ultrasound after completion of the arterial stiffness measures. Finally, a battery of cognitive tests (Verbal Fluency Test and Trails A+B tests) will be administered to the participant.

Interventions

BEHAVIORALMental Arithmetic Test

The researcher will call out a four-digit number and ask the participant to subtract either 7 or 13. Each minute, a new four-digit number will be called out and the participant must subtract the 7 or 13 from the number. The test will last approximately 5 minutes

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

PREVENTION

Masking

NONE

Intervention model description

Participants will be exposed to mental stress following either 20 min or 120 min sitting

Eligibility

Sex/Gender

ALL

Age

35 Years to 59 Years

Healthy volunteers

Yes

Inclusion criteria

* Healthy male or female

Exclusion criteria

* Any known cardio-metabolic disorders * Taking medications known to affect cardiovascular function * Report drug or alcohol abuse * Report cigarette smoking * Pregnant women

Design outcomes

Primary

Measure	Time frame	Description
Mean Change in Brachial-femoral Pulse Wave Velocity (bfPWV)	Baseline and immediately following the acute mental stressor	bfPWV (m/s) is the velocity at which a pressure wave travels between the brachial and femoral arterial segments. An increase in bfPWV represents increased arterial stiffness (worse outcome).
Change in Heart-middle Cerebral Artery Pulse Wave Velocity (Brain PWV)	Baseline and immediately following the acute mental stressor	Brain PWV (cm/s) is the velocity at which a pressure wave travels between the heart and cerebrovascular system. An increase in Brain PWV represents increased arterial stiffness (worse outcome).

Secondary

Measure	Time frame	Description
Mean Change Augmentation Index	Baseline and immediately following the acute mental stressor	Augmentation Index is a measure of arterial wave reflection and calculated as augmentation pressure divided by central pulse pressure.
Mean Change Carotid-femoral Pulse Wave Velocity (PWV)	Baseline and immediately following the acute mental stressor	Carotid PWV (m/s) is the velocity at which a pressure wave travels between the carotid and femoral arterial segments. An increase in carotid PWV represents increased arterial stiffness (worse outcome).
Neurovascular Coupling	following the acute mental stressor	Neurovascular Coupling reflects the cerebral blood flow during a cognitive task.
Mean Executive Function	following the acute mental stressor	Executive Function was measured at the end of each condition by recording the completion time of a trail making test. The trail making test was delivered using a tablet and the time to complete the test was recorded. Subject instructed to connect a set of 25 dots as rapidly as possible.
Mean Change in Femoral-ankle PWV	Baseline and immediately following the acute mental stressor	Femoral-ankle PWV (m/s) is the velocity at which a pressure wave travels between the femoral-ankle arterial segments. An increase in femoral-ankle PWV represents increased arterial stiffness (worse outcome).

Countries

United States

Participant flow

Participants by arm

Arm	Count
All Participants All participants who completed both conditions in either Period 1 or Period 2 or Period 3 as per randomization schedule.	6
Total	6

Baseline characteristics

Characteristic	All Participants	—
Age, Continuous	43 years STANDARD_DEVIATION 8	—
Race and Ethnicity Not Collected	—	— Participants
Region of Enrollment United States	6 Participants	—
Sex: Female, Male Female	2 Participants	—
Sex: Female, Male Male	4 Participants	—

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	0 / 6	0 / 6
other Total, other adverse events	0 / 6	0 / 6
serious Total, serious adverse events	0 / 6	0 / 6

Outcome results

Primary

Change in Heart-middle Cerebral Artery Pulse Wave Velocity (Brain PWV)

Brain PWV (cm/s) is the velocity at which a pressure wave travels between the heart and cerebrovascular system. An increase in Brain PWV represents increased arterial stiffness (worse outcome).