Breaks in Sedentary Time and Glucose Regulation in Women

Study Overview
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Brief Summary
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The number of people diagnosed with Type 2 diabetes (T2DM) is increasing rapidly and about 2.9 million people in the UK currently have diabetes. There is increasing evidence suggesting that prolonged sedentary time may actually increase the risk of diabetes and other chronic diseases. Importantly, adults can meet public health guidelines on physical activity (150 minutes of moderate activity per week), but if they still sit for prolonged periods, their metabolic health is compromised. Going from sitting to standing and carrying out light-intensity activities (such as casual walking) may reduce diabetes risk. However, no one has investigated the effect of standing and walking on markers of cardio-metabolic markers in individuals with a high risk of T2DM. Therefore, the aim is to find out whether reducing the amount of time people spend sitting and replacing it with standing and light intensity activity (walking) reduces glucose, insulin and triglyceride levels, therefore reducing the risk of diabetes.

Official Title
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Does Breaking Sedentary Time Improve Glucose Regulation in Women With Impaired Glucose Tolerance? A Balanced Incomplete Block Design Study

Conditions
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Impaired Glucose Tolerance

Intervention / Treatment
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* Behavioral: Sitting
* Behavioral: Standing
* Behavioral: Walking


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Sedentary Overweight or obese (BMI>25kg/m2) Post menopausal Previous diagnosis of impaired glucose tolerance Exclusion Criteria: Regular purposeful exercise (≥150 minutes of MVPA per week) Physical condition which limits full participation in the study Active psychotic illness or other significant illness which, in the view of the investigators, would prevent full participation Inability to communicate in spoken English Steroid use Known Type 2 Diabetes Pregnancy Male Currently taking hormone replacement medication.

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 74 Years

Sexes Eligible for Study
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Female

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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sitting<br>During the sitting treatment condition, walking and standing will be restricted. Participants will be in a designated room with access to a computer, books/magazines throughout the day. Participants will have a cannula fitted and the first of the half-hourly blood samples will be taken (time point: -1hr). Participants will then be asked to sit quietly for 60 minutes to achieve a steady state. Following this, participants will have another blood sample taken and then be provided with a standardised mixed meal breakfast (09:00am) (time point: 0h). Blood sampling will continue at 30 minutes intervals for 3 hours following breakfast. A second, lunch meal (12:00pm), will be then be consumed over 15 minutes. Blood sampling will then continue at 30 minute intervals for 3 hours following lunch. | Behavioral: Sitting<br> <br> |
| Experimental: Standing<br>This is the same as the sitting condition, but participants will be asked to break their sitting time by standing close to their chair for 5 minutes, after 15 and 45 minutes of each hour following breakfast. The standing protocol will be repeated after lunch. Individuals will be asked to stand in the same position with no further instructions provided. In total, individuals will accumulate 12 bouts (60 minutes) of standing throughout the test period. | Behavioral: Standing<br> <br> |
| Experimental: Walking<br>This is identical to the standing condition, but the breaks in sitting time will be punctuated with 5 minute bouts of light-intensity treadmill walking (equivalent to around 4.0km•h-1) rather than standing. In total, individuals will accumulate 12 bouts (60 minutes) of light-intensity activity throughout the test period. The light-intensity walking activity undertaken here replicates the low-grade ambulatory activity associated with everyday life. | Behavioral: Walking<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glucose area under the curve | Glucose area under the curve (AUC); Plasma glucose will be measured using a glucose oxidase method on the Beckman Auto Analyzer (Beckman, High Wycombe, UK). Glucose profile measurements will be undertaken in the same laboratory located within the Leicester Royal Infirmary. | 0 weeks and 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin area under the curve |  | 0 weeks and 2 weeks | 
| Triacylglycerol area under the curve |  | 0 weeks and 2 weeks | 
| Lipoprotein lipase activity |  | 0 weeks and 2 weeks |