Impact of 16 weeks exercise training on mitochondrial activity and fat metabolism in skeletal muscle tissue of SPIRIT study cohort

The South Pacific Islands Resist diabetes with intense Training (SPIRIT) study is the first randomised trial of clinical exercise training in a cohort of Polynesian New Zealanders with type 2 diabetes mellitus (T2DM) and visceral obesity (n=18; BMI 43.8 ± 9.5 kg/m2; mean waist circumference 128.7 ± 18.7 cm). Preliminary results from the SPIRIT study show no improvement in glycaemic control and little change in other related parameters examined after 16 weeks of progressive resistance training (PRT) or aerobic exercise (AER). In several studies it has been shown that the mitochondrial activity and lipid metabolism in skeletal muscle of people with T2DM decreases. We propose that the metabolic adaptation in this cohort is either delayed or overwhelmed by the effect of increased fat mass. The activity of key enzymes for Krebs cycle (citrate synthase-CS), fat metabolism (beta hydrxoyacyl CoA dehydrogeanse-BHAD) and electron transport chain (cytochrome C oxidase-COX) were measured in the skeletal muscle tissue at 0 and 16 weeks. The results support our hypothesis and indicate that metabolic adaptation is occurring but the benefits are not yet observed at the macro-physiological level.