Skeletal Muscle Microvascular-Linked Improvements in Glycemic Control From Resistance Training in Individuals With...

Area of Science:

• Exercise physiology
• Metabolic disease research
• Cardiovascular health

Background:

• Insulin enhances glucose uptake by improving muscle microvascular blood flow (MBF).
• This insulin-mediated microvascular function is impaired in individuals with insulin resistance and type 2 diabetes.
• Resistance training (RT) is known to improve glycemic control and insulin sensitivity.

Purpose of the Study:

• To investigate if RT-induced improvements in glycemic control in type 2 diabetes are associated with enhanced skeletal muscle microvascular responses.
• To assess the impact of RT on microvascular blood flow in skeletal muscle and skin following an oral glucose challenge.

Main Methods:

• Seventeen sedentary type 2 diabetes patients completed 6 weeks of whole-body RT.
• Measurements included fasting clinical chemistries, an oral glucose challenge (OGC), forearm muscle MBF, skin MBF, brachial artery flow, and body composition (DEXA).
• Microvascular assessments were performed at baseline and 60 minutes post-OGC before and after the RT intervention.

Main Results:

• RT significantly increased the muscle MBF response to the OGC, while skin microvascular responses remained unchanged.
• These microvascular adaptations correlated with significant improvements in glycemic control (fasting glucose, HbA1c, OGC glucose AUC).
• RT also led to increased lean body mass, reduced body fat, and improvements in lipid profiles and advanced glycation end products.

Conclusions:

• Whole-body resistance training enhances OGC-stimulated muscle MBF in type 2 diabetes patients.
• The improvements in muscle microvascular function occur concurrently with enhanced glycemic control.
• These findings suggest that increased muscle MBF is a significant contributor to the beneficial effects of RT on glucose metabolism in type 2 diabetes.