Effects of Physical Inactivity on Insulin Sensitivity, Appetite, Energy Balance, and Cardiovascular Responses in Humans.
Study Details
Study Description
Brief Summary
Physical inactivity is a significant predictor of major non-communicable diseases such as type 2 diabetes (7%), cardiovascular disease (6%), musculoskeletal disorders and some cancers, and has been proposed to be the 4th leading cause of death worldwide. Reduced physical activity leads to an impaired function of the hormone insulin and increased adiposity. Thus, the elimination of physical inactivity would remove between 6% and 10% of the major non-communicable diseases and increase life expectancy. The aim of the study is to investigate the effects of a short-term (2-day) period of reduced physical activity, with and without a proportional decrease in energy intake, on the action of insulin to regulate blood sugar fluctuations, appetite, and cardiovascular parameters (heart rate, cardiac output, stroke volume, blood flow, arterial blood pressure, peripheral vascular resistance) in response to food ingestion.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: Control 2 consecutive days of standardised daily levels of moderate physical activity (PAL=1.85 reflecting their habitual levels), and matched energy (food) intake |
Other: Control
Normal physical activity and standard energy intake
|
| Experimental: SIT+E 2 consecutive days of reduced physical activity induced by prolonged periods of sitting (PAL=1.4) whilst maintaining the level of food intake prescribed in the Control trial, thus creating a positive energy balance |
Other: SIT+E
Reduced physical activity and standard energy intake
|
| Experimental: SIT=E 2 consecutive days of reduced physical activity induced by prolonged periods of sitting (PAL=1.4) whilst reducing food intake to match the reduction in energy expenditure induced by inactivity, thus maintaining energy balance |
Other: SIT=E
Reduced physical activity and reduced energy intake
|
Outcome Measures
Primary Outcome Measures
- The incremental area under curve for Insulin [Over three hours from baseline]
The incremental area under curve for Insulin will be calculated using samples collected at 20 minute intervals between baseline and three hours
Secondary Outcome Measures
- The incremental area under curve for arterialized whole blood glucose [Over four hours from baseline]
The incremental area under curve for arterialized whole blood glucose will be calculated using samples collected at 10 minute intervals between baseline and four hours
Other Outcome Measures
- The incremental area under curve for free fatty acids [Over three hours from baseline]
The incremental area under curve for free fatty acids will be calculated using samples collected at 20 minute intervals between baseline and three hours
- The incremental area under curve for Triglycerides [Over three hours from baseline]
The incremental area under curve for Triglycerides will be calculated using samples collected at 20 minute intervals between baseline and three hours
- The incremental area under curve for Ghrelin [Over four hours from baseline]
The incremental area under curve for Ghrelin will be calculated using samples collected at one hour intervals between baseline and four hours
- The incremental area under curve for composite satiety score [Over four hours from baseline]
Composite satiety score will be calculated using 100mm visual analogue score ratings of satiety, fullness, hunger, desire to eat and prospective food consumption collected every 20 minutes between baseline and four hours.
- Weight of consumption of a pasta meal three hours after baseline [Three hours post baseline]
Weight of pasta consumed from a bowel refilled prior to being empty until participants feel comfortably full
- The incremental area under curve for cardiovascular parameters [Over three hours from baseline]
The incremental area under curve for mean blood pressure,cardiac output, stroke volume, peripheral resistance, heart rate, systolic blood pressure and diastolic blood pressure continuously over three hours from baseline using Finometer
- The incremental area under curve for limb blood flow [Over three hours from baseline]
The incremental area under curve for limb blood flow measured at 30 minute intervals between baseline and three hours using venous occlusion plethysmography
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Non-smoking
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Males and females
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Age (18-35 years old)
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Body mass index (BMI) of 18-27 kg/m2
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Waist circumference <94cm for males and <80cm for females
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Ability to give informed consent
Exclusion Criteria:
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Smoking
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Any metabolic (e.g. diabetes), endocrine (e.g. hyperthyroidism) or cardiovascular (e.g. heart or blood) abnormalities including hypertension or heart failure
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Clinically significant abnormalities on screening including ECG abnormalities
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Taking routine medication that may alter cardiovascular function and blood flow (e.g. blood pressure-lowering drugs or drugs that cause hypertension)
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Well trained individuals with PAL>2.00; on an energy-restricted diet or seeking to lose weight
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High alcohol consumption (<3-4 units/d for men; <2-3 units/d for women)
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Females who are pregnant or lactating; self-reported allergy, intolerance or strong dislike of foods or drinks to be offered for the test breakfast, pasta meal or during the intervention period
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Beck Depression Inventory score >10 and Eating Attitudes Test (EAT-26) score >20 as self-reported markers of symptoms and concerns characteristic of depression and eating disorders, respectively.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | University of Nottingham | Nottingham | United Kingdom |
Sponsors and Collaborators
- University of Nottingham
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- I200317