Aerobic training improves bone fragility by reducing the inflammatory microenvironment in bone tissue in type 2...

Area of Science:

• Endocrinology
• Orthopedics
• Exercise Physiology

Background:

• Type 2 diabetes mellitus (T2DM) is associated with hyperglycemia and inflammation, negatively impacting bone health.
• Aerobic training (AT) is recognized for its benefits in managing T2DM and improving bone quality, but optimal intensity and mechanisms remain unclear.

Purpose of the Study:

• To investigate the effects of two different intensities of aerobic training on bone quality in a mouse model of T2DM.
• To explore the underlying mechanisms, including metabolic parameters, inflammatory markers, and bone morphometry and biomechanics.

Main Methods:

• A mouse model of T2DM was subjected to sedentary conditions or two intensities of aerobic training (low: 8 m/min, 5° slope; high: 18 m/min, 15° slope) for two months.
• Measurements included metabolic parameters, serum and tibial concentrations of cytokines (IL-10, TNF-α), lipocalin-2 (LCN-2), adiponectin, and protein carbonylation (CO).
• Femur morphometry and biomechanical properties were assessed, followed by correlation analysis.

Main Results:

• Low-intensity AT in T2DM mice increased IL-10, improved trabecular bone structure (BV/TV, Tb.Sp.), and reduced bone CO, TNF-α, and LCN-2 compared to sedentary T2DM mice.
• High-intensity AT in T2DM mice demonstrated a more significant hypoglycemic effect, enhanced cortical bone density and fracture resistance, and reduced bone TNF-α, LCN-2, and CO compared to sedentary T2DM mice.

Conclusions:

• Aerobic training, at both low and high intensities, effectively improves bone morphometry and biomechanical properties in T2DM mice.
• These improvements are associated with a reduction in the bone's inflammatory microenvironment, mediated by decreased levels of TNF-α, LCN-2, and protein carbonylation.