Acute Effects of Postabsorptive and Postprandial Physical Activity

Study Overview
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Brief Summary
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Physical activity performed in the postprandial state has the ability to blunt postprandial glycemia acutely, even as a result of very light or small amounts of postprandial physical activity. Postprandial physical activity decreases postprandial glycemia more effectively than activity performed in the post-absorptive state. However, studies comparing postprandial and postabsorptive physical activity have measured glycemic outcomes in only short periods of time (hours) or have used a very large dose of physical activity. Physical activity have the ability to entail an acute increase in markers of systemic inflammation.Previous studies has also shown that systemic inflammation is increased during glycemic spikes, such as after a high carbohydrate load. Therefore the effect of postprandial physical activity is difficult to predict. One one hand it might increase markers of systemic inflammation. On the other hand it might decrease systemic inflammation as a result of a blunting effect on postprandial glycemia. The effect of physical activity after carbohydrate intake might therefore also differ from postabsorptive physical activity. Purpose of the study: I) The investigators hypothesized that light physical activity performed in the post-prandial sate decrease blood glucose in a day and night cycle compared to the same activity performed in the postabsorptive state and a control day. II) To test whether postabsorptive and postprandial light physical activity do affect markers of systemic inflammation different. 12 participants diagnosed with hyperglycemia but not on hypoglycemic medication took part in a randomized cross-over trial with 3 test days. A control day with no physical activity, and two days similar to the control day except that one of them contained a one hour bout of treadmill walking prior to breakfast and the other a similar exercise bout after breakfast. Continuous glucose monitoring was performed from start of exercise / breakfast until the morning next day (at least 22 hours). Venous blood was also sampled at given timepoints (before exercise / before breakfast, and 1.5, 2.5, 3.5 and 24 hours after breakfast. Dietary intake was individually standardized prior to and during test days.

Detailed Description
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Physical activity performed in the postprandial state has the ability to blunt postprandial glycemia acutely, even as a result of very light or small amounts of postprandial physical activity. Postprandial physical activity decreases postprandial glycemia more effectively than activity performed in the post-absorptive state. However, studies comparing postprandial and postabsorptive physical activity have measured glycemic outcomes in only short periods of time (hours) or have used a very large dose of physical activity. Physical activity have the ability to entail an acute increase in markers of systemic inflammation.Previous studies has also shown that systemic inflammation is increased during glycemic spikes, such as after a high carbohydrate load. Therefore the effect of postprandial physical activity is difficult to predict. One one hand it might increase markers of systemic inflammation. On the other hand it might decrease systemic inflammation as a result of a blunting effect on postprandial glycemia. The effect of physical activity after carbohydrate intake might therefore also differ from postabsorptive physical activity. Purpose of the study: I) The investigators hypothesized that light physical activity performed in the post-prandial sate decrease blood glucose in a day and night cycle compared to the same activity performed in the postabsorptive state and a control day. II) To test whether postabsorptive and postprandial light physical activity do affect markers of systemic inflammation different. 12 participants diagnosed with hyperglycemia but not on hypoglycemic medication took part in a randomized cross-over trial with 3 test days. A control day with no physical activity, and two days similar to the control day except that one of them contained a one hour bout of treadmill walking prior to breakfast and the other a similar exercise bout after breakfast. Continuous glucose monitoring was performed from start of exercise / breakfast until the morning next day (at least 22 hours). Venous blood was also sampled at given timepoints (before exercise / before breakfast, and 1.5, 2.5, 3.5 and 24 hours after breakfast. Dietary intake was individually standardized prior to and during test days.

Official Title
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Acute Effects of Postabsorptive and Postprandial Physical Activity on Glycemia and Inflammation

Conditions
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Hyperglycemia, Inflammation

Intervention / Treatment
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* Behavioral: postprandial and postabsorptive physical activity on treadmill


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosed with hyperglycemia Exclusion Criteria: Use of hypoglycemic agents or diseases directly affecting blood glucose, except of diabetes type 2 / insulin resistance
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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control<br>No physical activity | |
| Experimental: Postabsorptive physical activity<br>Physical activity performed before breakfast | Behavioral: postprandial and postabsorptive physical activity on treadmill<br> <br> |
| Experimental: Postprandial physical activity<br>Physical activity performed in the postprandial period after breakfast | Behavioral: postprandial and postabsorptive physical activity on treadmill<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in interstitial glucose from test day to test day | Interstitial glucose, measured by continuous glucose monitoring | Measured continuously on each test day, but a mean of every 5. minute during test day (from breakfast until 22 hours after breakfast) is stored and used for analysis (acute effect in a cross-over design). | 
| Change in hsCRP from test day to test day | This is a marker of inflammation, it will be measured from plasma of venous blood samples | Measured on each test day (acute effect in a cross-over design). A mean of the samples before exercise / before breakfast, and 1.5, 2.5, 3.5 and 24 hours after breakfast is used for analysis of change from test day to test day | 
| Change in VCAM from test day to test day | This is a marker of inflammation, it will be measured from plasma of venous blood samples | Measured on each test day (acute effect in a cross-over design). A mean of the samples before exercise / before breakfast, and 1.5, 2.5, 3.5 and 24 hours after breakfast is used for analysis of change from test day to test day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Blood glucose (venous samples) from test day to test day | Plasma samples of venous blood | Measured on each test day (acute effect in a cross-over design). A mean of the samples before exercise / before breakfast, and 1.5, 2.5, 3.5 and 24 hours after breakfast is used for analysis of change from test day to test day | 
| Change in triglycerides from test day to test day | Plasma samples of venous blood | Measured on each test day (acute effect in a cross-over design). A mean of the samples before exercise / before breakfast, and 1.5, 2.5, 3.5 and 24 hours after breakfast is used for analysis of change from test day to test day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Blood glucose (indicated by interstitial glucose), Markers of systemic inflammation