Sex Differences in the effecTs of brEaking uP Sedentary Behavior on vascUlar Function in Type 2 Diabetes

Study Overview
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Brief Summary
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Type 2 diabetes (T2D) confers a high risk of cardiovascular disease (CVD), particularly among older adults who tend to be physically inactive. Prolonged sedentary behavior (SB) has been shown to negatively influence markers of cardiovascular risk (e.g., blood glucose, blood pressure), even among individuals who are physically active. Most studies that have examined the effects of breaking up SB have focused on young healthy males and prioritized glycemic outcomes. Additionally, sex differences in these outcomes have not been adequately examined. The present study will address these gaps. This 3-arm crossover randomized controlled trial will compare the effects of 3 SB conditions on markers of vascular function. The 3 conditions are: 1) 4 hours of prolonged SB, 2) 4 hours of SB broken up by 5 minutes of self-paced walking every hour, and 3) 4 hours of SB with one 20-minute bout of self-paced walking. In addition to examining the overall effects of each condition, sex differences in physiological responses will be evaluated.

Official Title
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Sex Differences in the effecTs of brEaking uP Sedentary Behavior on vascUlar Function in Type 2 Diabetes

Conditions
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Type 2 Diabetes, Cardiovascular Diseases

Intervention / Treatment
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* Behavioral: prolonged SB
* Behavioral: SB broken 1
* Behavioral: SB broken 2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥60 years Postmenopausal (females only, ≥12 months without a menstrual period) Type 2 diabetes (hemoglobin A1c ≥6.5% and/or previous diagnosis of type 2 diabetes) ≥6 hours/day sedentary (assessed via IPAQ) Willingness to abstain from food, caffeine, alcohol and exercise for >= 24 hours, and tobacco/smoking for ≥12 hours prior to each intervention visit Ability to speak and read English Exclusion Criteria: Type 1 diabetes Uncontrolled hypertension (resting systolic ≥160 or diastolic ≥110 mmHg) Initiation of hormone therapy or change in hormone therapy dose/frequency/route of administration in the previous 3 months Renal dialysis History of deep vein thrombosis (DVT) Evidence of cognitive impairment that could impact ability to consent and/or participation (Mini-Cog score <3) Achieving physical activity guidelines (≥150 minutes of MVPA/week, assessed via IPAQ)) Physical impairment or disability that interferes with ability to engage in PA (e.g., severe osteoarthritis, lower extremity amputation [other than toe(s)/partial foot], use of a walker or wheelchair, etc.), Unstable medical/psychiatric condition that could impact study participation

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Participants will complete three interventions in a randomized order, separated by >=6 and <90 days. The interventions are: 4 hours of prolonged SB (control, CON) 4 hours of SB broken up by 5 minutes of self-paced walking every hour (BREAK) 4 hours of SB with one 20-minute bout of self-paced walking (BOUT)
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CON<br>Control group | Behavioral: prolonged SB<br>* 4 hours of prolonged SB<br>|
| Experimental: Break<br> | Behavioral: SB broken 1<br>* 4 hours of SB broken up by 5 minutes of self-paced walking every hour<br>|
| Experimental: BOUT<br> | Behavioral: SB broken 2<br>* 4 hours of SB with one 20-minute bout of self-paced walking<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| iAUC of SBP | Net incremental area under the curve (iAUC) of systolic blood pressure (SBP) | 90 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Net iAUC of DBP | Net iAUC of diastolic blood pressure | 90 days | 
| Net iAUC of of MAP | Net iAUC of mean arterial pressure | 90 days | 
| Net iAUC of HR | Net iAUC of heart rate | 90 days |