A pilot randomized controlled trial of 6-week combined exercise program on fasting insulin and fitness levels in individuals with spinal cord injury

Purpose The aim of this randomized controlled trial study was to investigate the effect of combined exercise program on the fasting insulin and fitness levels of people with spinal cord injury (SCI). Methods A total of 19 individuals with SCI participated in a combined exercise program consisting of aerobic and resistance exercises for 60 min per day, 3 days per week for 6 weeks. Peak oxygen consumption, body mass index, percent body fat, waist circumference, shoulder abduction and adduction, shoulder flexion and extension, elbow flexion and extension, fasting insulin levels, and homeostasis model assessment of insulin resistance (HOMA-IR) levels were measured at baseline and after the intervention. Results The 6-week exercise program significantly decreased the average fasting insulin (baseline: 7.5 ± 4.7 µU/ml vs. post-intervention: 4.5 ± 2.2 µU/ml, p < 0.05) and HOMA-IR (baseline: 1.5 ± 1.0 vs. post-intervention: 0.9 ± 0.4, p < 0.05) in the exercise group, whereas there was no change in control group (between group difference, mean fasting insulin: − 3.2 µU/ml, p = 0.003; mean HOMA-IR: − 0.66, p = 0.001). In addition, muscle strength of the shoulder flexors, extensors, abductors, adductors, and elbow flexors was significantly improved in the exercise group compared to the controls. Conclusion A combined exercise program is effective in decreasing fasting insulin and HOMA-IR levels while improving fitness in those with SCI. Graphical abstract These slides can be retrieved under Electronic Supplementary Material.