The effects of yoga among adults with type 2 diabetes: A systematic review and meta-analysis

Abstract

The purpose of this meta-analysis was to examine the effects of yoga for glycemic control among adults with type 2 diabetes (T2DM). Comprehensive electronic databases searches located 2559 unique studies with relevant key terms. Studies were included if they (1) evaluated a yoga intervention to promote T2DM management, (2) used a comparison group, (3) reported an objective measure of glycemic control at post-intervention, and (4) had follow-up length or post-test of at least 8weeks from baseline. Independent raters coded participant, design and methodological characteristics and intervention content. Summary effect sizes and 95% confidence intervals (CI) were calculated. Twenty-three studies with 2473 participants (mean age=53years; 43% women) met eligibility criteria. Compared with controls, yoga participants were successful in improving their HbA1c (d+=0.36, 95% CI=0.16, 0.56; k=16), FBG (d+=0.58, 95% CI=0.40, 0.76; k=20), and PPBG (d+=0.40, 95% CI=0.23, 0.56; k=14). Yoga was also associated with significant improvements in lipid profile, blood pressure, body mass index, waist/hip ratio and cortisol levels. Overall, studies satisfied an average of 41% of the methodological quality (MQ) criteria; MQ score was not associated with any outcome (Ps >0.05). Yoga improved glycemic outcomes and other risk factors for complications in adults with T2DM relative to a control condition. Additional studies with longer follow-ups are needed to determine the long-term efficacy of yoga for adults with T2DM.

Keywords: Diabetes; Meta-analysis; Review; Yoga.

Conflict of interest statement

Conflict of interest

The authors declare no conflict of interest.

Copyright © 2017 Elsevier Inc. All rights reserved.

Figures

Fig. 1

Study retrieval and selection.

Fig. 2

Forest plot for hemoglobin A1c. Note. The sizes of the boxes are proportional to the weight of each individual study in the analyses. The summary effect size is represented by a diamond. OHAs, oral hypoglycemic agents.

Fig. 3

Forest plot for fasting blood glucose. Note. The sizes of the boxes are proportional to the weight of each individual study in the analyses. The summary effect size is represented by a diamond. OHAs, oral hypoglycemic agents.

Fig. 4

Forest plot for post-prandial glucose. Note. The sizes of the boxes are proportional to the weight of each individual study in the analyses. The summary effect size is represented by a diamond. OHAs, oral hypoglycemic agents.