Cardiovascular Diseases, Cardiovascular Risk Factor, Diabetes, Physical Activity, Sedentary Lifestyle
Conditions
Brief summary
The purpose of this study is to examine whether breaking up prolonged sitting with short regular bouts of walking can reduce blood sugar and cholesterol levels after eating, which are risk markers for Type 2 diabetes and heart disease. This study will compare these responses in normal-weight versus overweight/obese South Asian adults.
Detailed description
Participants will attend a preliminary testing session where height, weight, body fat and waist circumference will be measured. They will be familiarised with a motorised treadmill that will be used during the experimental visit below and will take part in an exercise test to determine a light-intensity walking speed for the experimental visit. Participants will then attend two experimental visits in a random order: 1. Prolonged sitting (SIT): Participants will remain seated for 5 hours and instructed to reduce excessive movement. 2. Breaking up sitting with walking breaks (INT-SIT): Participants will rise from the seated position every 30 minutes throughout the experimental period to walk on a motorised treadmill at a light intensity for 5 minutes. After performing walking activity, they will return to the seated position. In addition, blood sample will be taken at the resting position just before each physical activity bout. The activity breaks will be undertaken on 9 occasions, providing a total of 45 min of light-intensity activity. During each visit, blood pressure will be taken 11 times and blood samples will be taken 10 times. Participants will be given a breakfast and lunch meal to consume.
Interventions
OTHERBreaking up sitting with walking breaks (INT-SIT)
See Breaking up sitting with walking breaks arm description
OTHERProlonged sitting (SIT)
See Prolonged sitting arm description
Sponsors
University of Bedfordshire
Brunel University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* Self-identified South Asian ethnicity. * Self-report sitting at least 7 hours per day. * Normal weight, overweight or obese.
Exclusion criteria
* Unable to speak and read English. * Contraindications to performing light-intensity walking. * Diagnosed cardiovascular disease or diabetes.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial Glucose | Measured over the 5 hour condition period | Incremental area under the curve for each 5 h condition will be calculated for glucose |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial Triglycerides | Measured over the 5 hour condition period | Incremental area under the curve for each 5 h condition will be calculated for triglycerides |
| Postprandial Insulin | Measured over the 5 hour condition period | Incremental area under the curve for each 5 h condition will be calculated for insulin |
| Metabolic Load Index | Measured over the 5 hour condition period | Incremental area under the curve for each 5 h condition will be calculated for the Metabolic Load Index (MLI). The MLI will be calculated using the following equation: MLI (mmol.L-1) = blood glucose (mmol.L-1) + TAG (mmol.L-1). Lower values of MLI are considered better for cardiometabolic health! |
| Resting Energy Expenditure | Measured for the 5 hour condition period | Incremental area under the curve for each 5 h condition will be calculated for resting energy expenditure |
| Resting Fat Oxidation | Measured for the 5 hour condition period | Incremental area under the curve for each 5 h condition will be calculated for resting fat oxidation |
| Resting Carbohydrate Oxidation | Measured for the 5 hour condition period | Incremental area under the curve for each 5 h condition will be calculated for resting carbohydrate oxidation |
| Mean Arterial Pressure | Measured over the 5 hour condition period | Mean Arterial Pressure (MAP) over the 5 h conditions. The following formula will be used to calculate MAP, where P is blood pressure (systolic or diastolic): MAP = PDiastolic + 1/3 (PSystolic - PDiastolic). |
| Heart Rate | Measured over the 5 hour condition period | Mean heart rate over the 5 h conditions |
Countries
United Kingdom
Participant flow
Recruitment details
A total of 54 South Asians (BMI\>18.0 kg.m\^2) aged between 18 and 75 years who were able to walk and perform LPA were recruited; data collection was performed between April 2019 and March 2020.
Pre-assignment details
Due to an acute bout of physical activity enhancing insulin sensitivity for up to 72 h, each condition was separated by a minimum of three days to eliminate potential carryover effects of the activity conditions. Female participants were asked to indicate the expected date of their menstruation. Based on the information, they were tested between 1 and 10 days in their follicular phase only to minimise the influence of hormonal fluctuations on blood glucose concentrations.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 44.1 years STANDARD_DEVIATION 14.2 |
| Body mass index (BMI) | 21.3 kg/m^2 STANDARD_DEVIATION 7.1 |
| Diastolic Blood Pressure | 80.3 mmHg STANDARD_DEVIATION 11 |
| Heart rate | 75.0 beats.min-1 STANDARD_DEVIATION 94 |
| % of Body fat | 23.6 % STANDARD_DEVIATION 5.8 |
| Race/Ethnicity, Customized Sub-Ethnic origin Bangladeshi | 11 Participants |
| Race/Ethnicity, Customized Sub-Ethnic origin Indian | 27 Participants |
| Race/Ethnicity, Customized Sub-Ethnic origin Nepali | 3 Participants |
| Race/Ethnicity, Customized Sub-Ethnic origin Paskistani | 1 Participants |
| Region of Enrollment United Kingdom | 14 participants |
| Sex: Female, Male Female | 22 Participants |
| Sex: Female, Male Male | 18 Participants |
| Systolic Blood Pressure | 121.8 mmHg STANDARD_DEVIATION 14.7 |
| Waist circumference | 91.8 cm STANDARD_DEVIATION 14.3 |
| Walking speed | 2.7 km.h-1 STANDARD_DEVIATION 0.7 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 54 | 0 / 54 |
| other Total, other adverse events | 0 / 54 | 0 / 54 |
| serious Total, serious adverse events | 0 / 54 | 0 / 54 |
Outcome results
None listed