Fitness and Fat Oxidation in Overweight Chinese, Indian and Malay Men
Study Details
Study Description
Brief Summary
South Asian men have lower cardiorespiratory fitness (CRF) than white men which is associated with a reduced capacity to oxidise fat during exercise. This is a risk factor for weight gain/regain. Whilst comparisons with Europeans are valuable, Asians are not a homogenous group and substantial differences in obesity and body fat partitioning exist with ethnicity. This cross-sectional pilot investigation aims to compare CRF and fat oxidation at rest and during exercise in Chinese, Indian and Malay men (from Singapore) with elevated BMI (23 -30 kg/m2). Forty-five men (15 each ethnicity) with elevated body mass index (23 -30 kg/m2) will complete testing in a fasted state on two separate mornings separated by ≥72 hours: (i) for a measure of CRF; and (ii) for a measure of fat oxidation at rest and during incremental exercise.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Detailed Description
South Asian men have lower cardiorespiratory fitness (CRF) than white men which is associated with a reduced capacity to oxidise fat during exercise. This is a risk factor for weight gain/regain. Whilst comparisons with Europeans are valuable, Asians are not a homogenous group and substantial differences in obesity and body fat partitioning exist with ethnicity. This cross-sectional pilot investigation aims to compare CRF and fat oxidation at rest and during exercise in Chinese, Indian and Malay men (from Singapore) with elevated BMI (23 -30 kg/m2). Forty-five men (15 each ethnicity) with elevated body mass index (23 -30 kg/m2) will complete testing in a fasted state on two separate mornings separated by ≥72 hours: (i) for a measure of CRF; and (ii) for a measure of fat oxidation at rest and during incremental exercise. A submaximal exercise test will be used to estimate CRF (maximum oxygen uptake, VO2max) during walking using a standard protocol where subjects walk on a treadmill at 5 km/h with regular increments in gradient until individuals reach 80% of their estimated maximum heart rate [220 - age (years)]. Perceived exertion will be monitored assessed periodically during the test and expired gases continuously measured via a mouthpiece attached to an automated metabolic cart (Parvomedics MMS-2400; Parvomedics, Sandy, UT). Oxygen consumption will be extrapolated to estimate VO2max based on estimated maximum heart rate. Resting fat oxidation will be determined via a 30 minute measure of expired gases under a ventilated hood attached to an automated metabolic cart. Fat oxidation during exercise will be determined via walking on a treadmill with increments in speed and gradient until the respiratory exchange ratio is ≥ 0.95. Primary outcomes will be compared among groups and adjusted for any covariates (e.g., BMI, body fat percentage) as necessary.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Chinese men Chinese men based on self-identity for three generations (parents and grandparents), age 25 - <45 years, who are physically inactive (< 150 minutes moderate or < 75 minutes vigorous leisure-time physical activity per week), with elevated body mass index (>23-<30 kg/m2) for Asians. Single measure of CRF, resting fat oxidation and fat oxidation during graded exercise. |
Other: Cardiorespiratory fitness test
Progressive submaximal exercise test on a treadmill to predict cardiorespiratory fitness
Other Names:
Other: Resting measure of fat oxidation
Use of ventilated hood attached to automated metabolic cart to measure substrate oxidation at rest
Other Names:
Other: Maximum fat oxidation test
Progressive exercise test to determine maximum fat oxidation during exercise
|
| Indian men Indian men based on self-identity for three generations (parents and grandparents), age 25 - <45 years, who are physically inactive (< 150 minutes moderate or < 75 minutes vigorous leisure-time physical activity per week), with elevated body mass index (>23-<30 kg/m2) for Asians. Single measure of CRF, resting fat oxidation and fat oxidation during graded exercise. |
Other: Cardiorespiratory fitness test
Progressive submaximal exercise test on a treadmill to predict cardiorespiratory fitness
Other Names:
Other: Resting measure of fat oxidation
Use of ventilated hood attached to automated metabolic cart to measure substrate oxidation at rest
Other Names:
Other: Maximum fat oxidation test
Progressive exercise test to determine maximum fat oxidation during exercise
|
| Malay men Malay men based on self-identity for three generations (parents and grandparents), age 25 - <45 years, who are physically inactive (< 150 minutes moderate or < 75 minutes vigorous leisure-time physical activity per week), with elevated body mass index (>23-<30 kg/m2) for Asians. Single measure of CRF, resting fat oxidation and fat oxidation during graded exercise. |
Other: Cardiorespiratory fitness test
Progressive submaximal exercise test on a treadmill to predict cardiorespiratory fitness
Other Names:
Other: Resting measure of fat oxidation
Use of ventilated hood attached to automated metabolic cart to measure substrate oxidation at rest
Other Names:
Other: Maximum fat oxidation test
Progressive exercise test to determine maximum fat oxidation during exercise
|
Outcome Measures
Primary Outcome Measures
- Cardiorespiratory fitness [1 day (Single measurement)]
Predicted measure of maximum oxygen uptake during exercise
- Resting fat oxidation [1 day (Single measurement)]
Measure of amount of fat oxidised whilst at rest in the postabsorptive (fasting) state
- Maximum fat oxidation (exercise) [1 day (Single measurement)]
Measure of maximum amount of fat oxidised whilst exercising in the postabsorptive state
Eligibility Criteria
Criteria
Inclusion Criteria:
-
male
-
age 25 - <45 years
-
Chinese, Indian or Malay based on self-identity for three generations (parents and grandparents)
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BMI ≥ 23 - < 30 kg/m2 and/or waist circumference ≥ 90 cm
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physically inactive defined as < 150 minutes moderate or < 75 minutes vigorous leisure-time physical activity per week, or the equivalent combination of both
Exclusion Criteria:
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females
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personal history of cardio-metabolic diseases
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dieting (i.e. restricting food/energy intake)
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smokers
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consuming alcohol > 3 times per week with > 3 drinks per time
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using any medications which affect carbohydrate or lipid metabolism
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any lower body injuries
-
fasting blood glucose > 6.1 mmol/L
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Human Bioenergetics Laboratory, National Institute of Education, Nanyang Technological University | Singapore | Singapore | 637616 |
Sponsors and Collaborators
- Nanyang Technological University
- Ministry of Education, Singapore
Investigators
- Principal Investigator: Stephen F Burns, PhD, Nanyang Technological University
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 2017-T1-002-036