Drop-out ratio between moderate to high-intensity physical exercise treatment by patients with, or at risk of, type 2 diabetes mellitus: A systematic review and meta-analysis

Aims: Physical exercise represents the cornerstone in the treatment for patients with type 2 diabetes mellitus (T2DM). However, it is not clear how different physical exercise intensities might affect the drop-out ratio. The aim of this review is to examine the extent to which exercise interventions impact dropout risk in patients with, or at risk of, T2DM. Methods: A Systematic review and meta-analysis of dropouts to aerobic exercise training interventions of varying intensity were conducted. Randomized controlled trials with exercise interventions on patients with, or at risk of, T2DM were included. The intervention had to last a minimum of three months and the studies had to include at least two groups (moderate- vs high-intensity exercise). Results: Twenty-three studies were selected for both systematic revision and meta-analysis. Although no difference between intensities groups have been seen (OR 1,12 [CI95% 0,85-1,47] p = 0,41), high intensity exercise training has a higher dropout risk than moderate exercise when both are conducted over a similar time period (OR 1,81 [CI95% 1,12-2,91] p = 0,01). Conclusion: It seems that high-intensity protocols did not decrease drop-out ratio. Although high-intensities are more time efficient than moderate intensities, the difficult to carry on the exercise might also become a barrier to take into consideration. Further research is needed to explore barriers and enablers to better understand patients' participation.