NCT04007926

Mechanisms of Insulin Resistance and Exercise in South Asians

Effects of Exercise Training on Insulin Sensitivity in South Asians at Risk of Diabetes: the Roles of Skeletal Muscle Microvasculature and Mitochondrial Metabolism

• Status: Suspended
• Phase: N/A
• Study type: Interventional
• Enrollment: 66 (estimated)
• Sponsor: University of Glasgow · Academic / Other
• Sex: Male
• Age: 30 Years – 65 Years
• Healthy volunteers: Accepted

Summary

This study determines the effect of aerobic and resistance exercise training on whole-body and skeletal muscle insulin sensitivity in south Asians and evaluate the mechanisms which contribute to improvements in insulin sensitivity after exercise training.

Detailed description

South Asians (SA) have 2-4 fold higher risk of type 2 diabetes and develop the disease at lower body weights and younger ages than white Europeans. Lower cardiorespiratory fitness and capacity for muscle fat oxidation contributes substantially to SAs' greater insulin resistance, the extent to which this can be improved by exercise training is unclear. This randomised controlled trial will investigate the effects of a 12-week aerobic or resistance exercise training intervention on insulin sensitivity (hyperinsulinaemic-euglycaemic clamp) in South Asian adults (22 control, 22 aerobic exercise group and 22 resistance exercise group). The study will also explore the mechanisms within skeletal muscle which mediate these changes by evaluating aerobic and resistance exercise-training induced changes: in basal and insulin-stimulated microvascular blood volume (using contrast-enhanced ultrasound); skeletal muscle mitochondrial function; and lipid droplet morphology and spatial interaction with mitochrondria, muscle fibre capillarisation, endothelial content of key enzymes controlling dilation/constriction and GLUT-4 translocation (using confocal immunofluorescence microscopy and transmission electron microscopy methods). Thus, this work will integrate physiological and molecular data to determine the extent to which exercise training can improve insulin sensitivity in SA and the mechanisms underpinning this improvement. This knowledge is important for optimising diabetes prevention interventions in SAs and identification of potential novel therapeutic targets.

Conditions

• Insulin Resistance

Interventions

Type	Name	Description
BEHAVIORAL	Aerobic exercise programme	Participants will start with 3 x 20 minute exercise sessions in the first week, building up to 5 x 60 minutes of exercise by weeks 9-12 of the intervention, at an intensity of 65-80% of predicted maximum heart rate.
BEHAVIORAL	Resistance exercise programme	Participants will undertake two supervised sessions per week. The exercises performed during each session will consist of leg press, calf press, leg extension, leg curl, chest press, shoulder press, lateral pull down and seated row. Exercises will be performed at 60-80% 1RM. In weeks 1-2 participants will perform, during each session, a single set of 5-10 repetitions of each exercise (tiring but comfortably achievable) to ensure they are comfortable with the exercises and are performing these in the correct form. In weeks 3-4 participants will perform, during each session, two sets of each exercise to voluntary muscular failure - defined as not being able to perform single another repetition. In weeks 5-12 this will progress to 3 sets of each exercise to voluntary muscular failure, in each session.

Timeline

• Start date: 2021-08-01
• Primary completion: 2023-03-01
• Completion: 2025-01-01
• First posted: 2019-07-05
• Last updated: 2020-10-08

Locations

1 site across 1 country: United Kingdom