Comparable anti-glycaemic effects of hypertrophy versus endurance resistance training in type 2 diabetes mellitus

The rising incidence and prevalence of type 2 diabetes mellitus (T2DM) call for effective control of cardiovascular risk factors in order to prevent or at least delay deleterious effects of non-communicable diseases. In concert with dietary and pharmacological interventions, exercise training is a cornerstone of disease management in diabetic patients. Since approximately 75% of the insulin-stimulated glucose uptake occurs in skeletal muscles, increasing muscle mass through resistance training appears as a logical therapeutic approach. We randomized 32 patients (mean age 64.8 7.8 years; 13 men and 19 women) with T2DM to eightweek programmes of hypertrophy resistance training (HRT) or endurance resistance training (ERT), both in combination with aerobic endurance training (AET), in order to assess their anti-glycaemic effects. Analyses of stored blood samples of 27 patients (mean age 63.7 8.1 years; 12 men and 15 women) were performed for: free fatty acids (FFAs), apolipoprotein A1, apolipoprotein B, high sensitivity C-reactive protein, C-peptide leptin, resistin, plasminogen activator inhibitor-1, insulin-like growth factor-1, cortisol and adiponectin. Maximal ergometry was performed and improvement was in line with recent literature. We have previously reported comparable increase in muscle mass and strength irrespective of the type of resistance training. The main findings of this analysis are that combined AET and resistance training beneficially alters markers of glycaemic control irrespective of the type of resistance training. In detail, FFA (p1⁄4 0.011), C-peptide (p1⁄4 0.014) and resistin (p1⁄4 0.036) showed statistically significant improvement whereas all other parameters remained statistically unchanged (Table 1; all p1⁄4 0.20–0.94). When data were analysed according to group assignment, trends were confirmed; however, statistical significance was lost, except for resistin as it increased by 17.9% (p< 0.001) in the HRT group compared with 3.9% (p1⁄4 0.737) in the ERT group (p< 0.001). Our observation that FFA decreases in T2DM patients extends the findings of Brooks et al. as the decrease occurred regardless of whether resistance training was performed as HRT or ERT. Also we report a significant and well comparable decrease of C-peptide in both resistance training programmes. It appears plausible that this is caused by a continuous increase in muscle strength rather than muscle mass. In obesity, resistin has been associated with an increased risk of atherogenesis and cardiovascular disease. There is no plausible cause for the observed increase in resistin, which we of course take note of but currently interpret as a chance finding. The results of this study confirm that patients with T2DM benefit from resistance training amongst others through anti-glycaemic effects. Since HRT and ERT emerge as equipotent with regard to their muscular and anti-glycaemic effects, both can be offered to our patients according to their preferences and needs, which will further contribute to individualized training prescription and possibly result in enhanced adherence.