Effect of revascularisation on lower extremity muscle function in combined type 2 diabetes and critical limb threatening ischemia.

BACKGROUND Critical limb-threatening ischemia (CLTI) and type 2 diabetes (T2D) frequently co-exist and often with less favourable outcome after revascularisation. The objective was to evaluate the effects of revascularisation on muscle function, perfusion and mitochondrial respiration in patients with combined CLTI and T2D. METHODS A prospective translational observational study. Two groups of patients facing unilateral peripheral revascularisation was included: Patients suffering from combined disease with CLTI+T2D (n= 14) and patients suffering from CLTI (n= 15). During pedal exercise testing, calf muscle perfusion was monitored with near-infrared spectroscopy (NIRS) and leg arterial volume flow in the common femoral artery with duplex ultrasound. Calf muscle biopsy and subsequent assessment of mitochondrial respiratory capacity on isolated muscle fibres was performed. Tests was performed before and six weeks after revascularisation. RESULTS After revascularisation, patients CLTI+T2D improved in muscle force from 8.48 kg (CI: 7.49-9.46) to 13.11 kg (CI: 11.58-14.63), (P<.001). Conversely, muscle force in patients suffering from nondiabetic CLTI decreased from 10.03 kg (CI: 9.1-10.96) to 9.73 kg (CI: 8.77- 10.69), (P=0.042). Muscle oxygenation during exercise improved more in the CLTI+T2D group 6.36 AUC (Area Under Curve), ((μM/kg)s) (CI: 5.71-7.01) compared to 2.11 ((μM/kg)s) (CI:1.38-2.83) in the CLTI group (P=.002). No improvement or difference between groups regarding mitochondrial function was detected. CONCLUSIONS Patients with combined CLTI+T2D, had an unsuspected better effect of revascularisation compared to patients with non-diabetic CLTI, in terms of increased muscle force (MVC) and improved muscle perfusion. Further studies are needed to elucidate the apparent interaction of the CLTI and T2D syndromes.