Effects of treadmill exercises on pancreatic β cell function through the role of vitamin D in patients with type 2 diabetes mellitus

Background: Vitamin D is a lipophilic compound that can be trapped in adipose tissue that is often obtained in metabolic syndrome. This study aims to compare 25(OH)D levels and pancreatic β cell function before and after moderate-intensity treadmill with increased speed and gradual inclination in type 2 diabetic patients. Method: In this quasi-experimental trial with a pretest-posttest design, 22 patients with T2DM were divided into 2 groups: The exercise group and the control group. Participants were assessed for clinical and biochemistry. Serum insulin, fasting blood glucose, 25(OH)D, and HOMA B were calculated. All measurements were performed at the beginning and after 4 weeks of training. Results: Vitamin D levels before and after the treadmill in the exercise group were 19.22 ± 4.06 ng/mL and 21.74 ± 4.53 ng/mL, respectively. While vitamin D levels before and after the treadmill in the control group were 21.71 ± 4.22 ng/mL and 23.25 ± 5.46 ng/mL, respectively. Vitamin D levels before and after the treadmill in the exercise group were significantly increased (p= 0.041) but not in the control group (p= 0.355). A significant improvement that was observed in the homeostatic model assessment of β cell function (HOMA B) was both significantly ameliorated (p= 0.013 and p= 0.032, respectively). Conclusion: Moderate intensity treadmill exercises with increased speed and gradual inclination can increase vitamin D levels and pancreatic β cell function.