Combined training and hormones/enzymes with insulinotropic actions in individuals with overweight and type 2 diabetes mellitus: A randomized controlled trial

The incretins (glucose-dependent insulinotropic polypeptide [GIP] and glucagon-like peptide-1 [GLP-1]), along with amylin/islet amyloid polypeptide (IAPP) and insulin-degrading enzyme (IDE), are hormones/enzymes that have been pharmacological targets, such as dipeptidyl peptidase-4 (DPP-4) inhibitors, due to their insulinotropic actions. Physical training is recommended as a treatment for type 2 diabetes mellitus (T2DM); however, its effects on the concentrations of these hormones/enzymes are not well known. Thus, the present study aimed to evaluate the effects of combined training (CT) on the concentrations of hormones/enzymes with insulinotropic actions in individuals with T2DM and overweight. Individuals of both sexes with T2DM (age 51.73 ± 4.19 years; body mass index [BMI] 29.46 ± 3.39 kg/m²) were randomly distributed in the control group (CG, n = 17) and the combined training group (CTG, n = 17). The CT consisted of strength followed by erobic training, 3 times/week, for 16 weeks. Functional variables, body composition, and serum biochemical analyses (clinical markers, GLP-1, GIP, DPP-4, amylin/IAPP, and IDE) were evaluated. The CTG showed a decrease in GLP-1 (pre: 32.8 ± 12.1, post: 28.4 ± 13.5, and p = 0.04) in the group/time analysis. In the evaluation of the Δ% of variation, CTG presented a decrease for GLP-1 (-9.3%; p = 0.03) and amylin/IAPP (-13.4%; p < 0.01), in addition to an increase for DPP-4 (6.2%; p = 0.04) enzyme. CT decreases the baseline levels of important hormones with insulinotropic actions in individuals with T2DM and overweight. The improvement in overall metabolism provided by CT must be the main reason for these effects. These results broaden the understanding of the effects and relationships between CT and glucose metabolism.