Mindfulness-based interventions for adults with type 2 diabetes mellitus: a systematic review and meta-analysis

Background: Type 2 diabetes mellitus (T2DM) can lead to macro- and microvascular complications. Mindfulness-based interventions (MBIs) may improve metabolic and psychological health in individuals with T2DM. We aimed to assess the efficacy of MBIs for management of T2DM. Methods: We searched five databases and two trial registries using a comprehensive search strategy developed by a multidisciplinary team including an information scientist. We included randomised controlled trials (RCTs) investigating MBIs for important clinical outcomes including psychological outcomes, quality of life, glycaemic control and cardiovascular risk factors in adults with T2DM. Where possible, random effects meta-analyses were conducted. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to assess certainty of the evidence. Results: We included 31 RCTs (2337 participants: 1107 intervention, 1230 control). We found very low certainty evidence that MBIs may reduce stress (standardized mean difference (SMD) –1.01, confidence interval (CI) –1.91 to –0.20, 8 trials, n = 528), depression (SMD –1.26, CI –2.08 to –0.43; 7 trials, n = 570) and anxiety (SMD –0.67, CI –1.27 to –0.08; 4 studies, n = 255) at end of treatment compared to waitlist control/usual care. MBIs may have a small effect on HbA1c and systolic/diastolic blood pressure at end of treatment compared to waitlist control/usual care (HbA1c mean difference (MD) –0.44, 95 % CI –0.71 to –0.17, 9 trials, n = 734; low certainty evidence). There was very low certainty evidence that MBIs + lifestyle may have no effect on HbA1c or body weight compared to lifestyle alone. Conclusion: MBIs may have clinical benefits (particularly psychological) for adults with T2DM, but lack of certainty in the evidence precludes clinical recommendations. Protocol registration: Cochrane Database of Systematic Reviews, DOI: 10.1002/14651858.CD014881.