Mitochondrial dysfunction in calf muscles of patients with combined peripheral arterial disease and diabetes type 2

This study elucidates the effects on muscle mitochondrial function in patients suffering from combined peripheral arterial disease (PAD) and type 2 diabetes (T2D) and the relation to patient symptoms and treatment.

Near infrared spectroscopy (NIRS) calf muscle exercise tests were conducted on 40 subjects, 15 (PAD), 15 (PAD+T2D) and 10 healthy age matched controls (CTRL) recruited from the vascular outpatient clinic at Gentofte County Hospital, Denmark. Calf muscle biopsies (~80 mg, gastrocnemius and anterior tibial muscles) were sampled and mitochondrial function tested applying high resolution oxygraphy on isolated muscle fibers.

The NIRS exercise tests showed evidence of mitochondrial dysfunction in the PAD+T2D group by a longer recovery of the deoxygenation resulting from exercise in spite of a higher exercise oxygenation level compared to the PAD group. This was confirmed by a ~30% reduction in oxygen consumption in the muscle biopsy tests for the PAD+T2D compared to the PAD group (P<0.05). We claim that this mitochondrial dysfunction partly explains the ~30% reduction in tread mill walking distance for the PAD+T2D group observed in this study.

These findings support the use of early surgical revascularization in the PAD+T2D group, in order to obtain better walking performance and probably reduced risk of permanent mitochondrial damage.