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Fitness and Fat Oxidation in Overweight Chinese, Indian and Malay Men

Completed
Conditions
Overweight and Obesity
Interventions
Other: Cardiorespiratory fitness test
Other: Resting measure of fat oxidation
Other: Maximum fat oxidation test
Registration Number
NCT05337111
Lead Sponsor
Nanyang Technological University
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.

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
45
Inclusion Criteria
  • male
  • age 25 - <45 years
  • Chinese, Indian or Malay based on self-identity for three generations (parents and grandparents)
  • BMI ≥ 23 - < 30 kg/m2 and/or waist circumference ≥ 90 cm
  • 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
  • females
  • personal history of cardio-metabolic diseases
  • dieting (i.e. restricting food/energy intake)
  • smokers
  • consuming alcohol > 3 times per week with > 3 drinks per time
  • using any medications which affect carbohydrate or lipid metabolism
  • any lower body injuries
  • fasting blood glucose > 6.1 mmol/L

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
Indian menCardiorespiratory fitness testIndian 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.
Indian menMaximum fat oxidation testIndian 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.
Malay menCardiorespiratory fitness testMalay 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.
Chinese menCardiorespiratory fitness testChinese 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.
Chinese menResting measure of fat oxidationChinese 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.
Malay menMaximum fat oxidation testMalay 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.
Chinese menMaximum fat oxidation testChinese 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.
Malay menResting measure of fat oxidationMalay 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.
Indian menResting measure of fat oxidationIndian 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.
Primary Outcome Measures
NameTimeMethod
Resting fat oxidation1 day (Single measurement)

Measure of amount of fat oxidised whilst at rest in the postabsorptive (fasting) state

Cardiorespiratory fitness1 day (Single measurement)

Predicted measure of maximum oxygen uptake during exercise

Maximum fat oxidation (exercise)1 day (Single measurement)

Measure of maximum amount of fat oxidised whilst exercising in the postabsorptive state

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

Human Bioenergetics Laboratory, National Institute of Education, Nanyang Technological University

🇸🇬

Singapore, Singapore

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