Effects of exercise training on quality of life, symptoms of depression, symptoms of anxiety and emotional well-being in type 2 diabetes mellitus: a systematic review

Psychological problems are relatively common in people with type 2 diabetes. It is unclear whether exercise training exerts an effect on quality of life, symptoms of depression, symptoms of anxiety and emotional well-being in people with type 2 diabetes. The aim of this study was to conduct a systematic review to assess the effects of exercise training on these outcomes in people with type 2 diabetes. MEDLINE, PsycINFO, Embase and ClinicalTrials.gov databases were searched. The review included randomised controlled trials (RCTs) of at least 4 weeks' duration in people with type 2 diabetes that evaluated the effect of exercise training on quality of life, symptoms of depression, symptoms of anxiety and/or emotional well-being compared with usual care. Of 1,261 retrieved articles, 20 RCTs were included with a total of 1,719 participants. Quality of life was assessed in 16 studies. Between-group comparisons showed no significant results for aerobic training with the exception of one study, and mixed results for resistance and combined training. Symptoms of depression were assessed in four studies. In only one study did the intervention decrease symptoms of depression. Emotional well-being was evaluated in four studies, which also showed conflicting results. Symptoms of anxiety were evaluated in one study, which showed a significant improvement. The effects of exercise training on psychological outcomes in people with type 2 diabetes are conflicting. Therefore, there is a need for further high-quality RCTs in order to gain greater insight into the role of exercise training in people with type 2 diabetes.