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

Differences in Cardiorespiratory Fitness and Fat Oxidation at Rest and During Exercise in Chinese, Indian and Malay Men With Elevated Body Mass Index.

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.

Study Overview

• Status: Completed
• Conditions: Overweight and Obesity
• Intervention / Treatment: Other: Cardiorespiratory fitness test; Other: Resting measure of fat oxidation; Other: Maximum fat oxidation test

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 Type: Observational
• Enrollment (Actual): 45

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 637616
    • Human Bioenergetics Laboratory, National Institute of Education, Nanyang Technological University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 45 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

• Sampling Method: Non-Probability Sample

Study Population

Healthy but physically inactive Chinese, Indian and Malay men aged 21-45 years with an elevated body mass index for Asians.

Description

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 Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	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: Graded exercise test, submaximal oxygen uptake test; Other: Resting measure of fat oxidation; Use of ventilated hood attached to automated metabolic cart to measure substrate oxidation at rest; Other Names: Resting energy expenditure, resting substrate oxidation test; 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: Graded exercise test, submaximal oxygen uptake test; Other: Resting measure of fat oxidation; Use of ventilated hood attached to automated metabolic cart to measure substrate oxidation at rest; Other Names: Resting energy expenditure, resting substrate oxidation test; 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: Graded exercise test, submaximal oxygen uptake test; Other: Resting measure of fat oxidation; Use of ventilated hood attached to automated metabolic cart to measure substrate oxidation at rest; Other Names: Resting energy expenditure, resting substrate oxidation test; Other: Maximum fat oxidation test; Progressive exercise test to determine maximum fat oxidation during exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiorespiratory fitness	Predicted measure of maximum oxygen uptake during exercise	1 day (Single measurement)
Resting fat oxidation	Measure of amount of fat oxidised whilst at rest in the postabsorptive (fasting) state	1 day (Single measurement)
Maximum fat oxidation (exercise)	Measure of maximum amount of fat oxidised whilst exercising in the postabsorptive state	1 day (Single measurement)

Collaborators and Investigators

• Sponsor: Nanyang Technological University
• Collaborators: Ministry of Education, Singapore
• Investigators: Principal Investigator: Stephen F Burns, PhD, Nanyang Technological University

Publications and helpful links

General Publications

• Demashkieh M, Dalan R, Burns SF. Cardiorespiratory fitness and fat oxidation during exercise in Chinese, Indian, and Malay men with elevated body mass index. Appl Physiol Nutr Metab. 2022 Aug 1;47(8):888-892. doi: 10.1139/apnm-2022-0106. Epub 2022 Jun 9.

Study record dates

Study Major Dates

• Study Start (ACTUAL): July 1, 2019
• Primary Completion (ACTUAL): March 30, 2020
• Study Completion (ACTUAL): July 31, 2020

Study Registration Dates

• First Submitted: April 14, 2022
• First Submitted That Met QC Criteria: April 19, 2022
• First Posted (ACTUAL): April 20, 2022

Study Record Updates

• Last Update Posted (ACTUAL): April 20, 2022
• Last Update Submitted That Met QC Criteria: April 19, 2022
• Last Verified: April 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight; Overweight
• Other Study ID Numbers: 2017-T1-002-036

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: A copy of the anonymised data relating to this study will be made available in the Data Repository of the National Institute of Education (Singapore) after publication. Access to the data will be via reasonable request to the Principal Investigator.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No