Related Experiment Video
Updated: Apr 8, 2026

Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test OGTT and Insulin Tolerance Test ITT
Published on: January 7, 2018
Cold-induced metabolic flexibility explains ethnic disparities among individuals with obesity and insulin resistance
Lijuan Sun1, Hui Jen Goh1, Xinyan Bi2
1Institute for Human Development and Potential (IHDP), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
Background:
Cold-induced thermogenesis (CIT) mediated by brown adipose tissue (BAT) and skeletal muscle holds therapeutic utility for obesity, but relative tissue contribution to CIT-driven metabolic flexibility (MetF) and its correlation to insulin resistance remain undefined across diverse ethnicities.
Objective:
This study aimed to investigate ethnic differences in cold-induced MetF and its link to insulin sensitivity in Chinese and Asian Indian individuals with overweight.
Design:
Forty-one participants with pre-metabolic or metabolic syndrome of two ethnic groups (31 Chinese, 10 Indian), with an average body mass index (BMI) of 27.5 kg/m2 underwent whole-body calorimetry following 1-h cold exposure (~14.5 °C) and oral glucose tolerance test (OGTT) in a crossover design. Resting metabolic rate (RMR), respiratory exchange ratio (RER), carbohydrate oxidation (COX), and fat oxidation (FOX) were assessed. Blood glucose and insulin were measured to assess insulin sensitivity.
Results:
Asian Indians had significantly higher fasting insulin levels and lower insulin sensitivity than Chinese participants. Chinese participants had greater increase in energy expenditure and a more pronounced fuel switch (RER, COX and FOX) with cold. For Chinese individuals, better cold-induced MetF was independently associated with lower fasting insulin and insulin resistance, even after adjusting for age, sex, and body fat. This association was not observed in Asian Indians.
Conclusion:
Significant ethnic differences exist in the association of CIT-driven MetF to insulin resistance. Chinese individuals exhibited robust MetF-insulin sensitivity correlation, whereas Asian Indians showed a blunted response without such independent association. This suggests that ethnicity-specific strategies targeting MetF are crucial for addressing metabolic health disparities.
More Related Videos
Related Concept Videos
Metabolic States of the Body: Fasting and Starvation
Regulation of Metabolism
Metabolic States of the Body: The Postabsorptive State
Initially, glycogen stored in the liver is broken down to release glucose into the bloodstream, while glycogen in the muscles is broken down to supply glucose for energy directly within the muscle cells. As glycogen stores diminish,...
Overview of Carbohydrate Metabolism
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion
Obesity

