Effect of yoga on glycemia and lipid parameters in type-2 diabetes: a meta-analysis

Abstract

Purpose: Prior systematic reviews on yoga and diabetes have given conflicting results. They have been limited by inclusion of uncontrolled unblinded single group observational studies. No reviews are available which have used the Cochrane methodology and GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. This meta-analysis evaluated the efficacy of yoga on glycaemia and lipids in T2DM using the Cochrane methodology and GRADE approach.

Methods: Major repositories were searched to pick randomized controlled trials involving T2DM patients receiving yoga. Primary outcome was to evaluate changes in fasting plasma glucose (FPG) and glycated haemoglobin (HbA1c). Secondary outcomes were to evaluate changes in post-prandial plasma glucose (PPG), total cholesterol (TC), triglycerides, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). Sub-group analysis involving people undergoing structured exercise regimen (SER) versus those undergoing standard diabetes care in controls was done.

Results: Data from 13 studies involving 1440 patients were analysed. Compared to controls, individuals doing yoga had significantly lower FPG [mean difference (MD) -17.22 mg/dl (95% CI: -26.19 - -8.26 mg/dl); p < 0.01; considerable heterogeneity (CH); low certainty of evidence (LCE)], PPG [MD -27.77 mg/dl (95% CI: -35.73 - -19.81 mg/dl); p < 0.01; low heterogeneity; moderate certainty of evidence (MCE)], TC [MD -19.48 mg/dl (95% CI: -31.97 - -6.99 mg/dl); p < 0.01; CH; LCE], triglycerides [MD -12.99 mg/dl (95% CI: -23.74 - -2.25 mg/dl); p < 0.01; CH; LCE], LDL-C [MD -11.71 mg/dl (95% CI: -17.49 - -5.93 mg/dl); p < 0.01; I² = 69% CH; LCE] and significantly higher HDL-C [MD 4.58 mg/dl (95% CI: 3.98-5.18 mg/dl); p < 0.01; low heterogeneity; MCE]. On sub-group analysis, where yoga was compared to SER, FPG was significantly lower in yoga group.

Conclusion: Yoga improves glycaemia and lipid parameters in T2DM with additional benefits seen both in people doing/not doing structured exercise.

Supplementary information: The online version contains supplementary material available at 10.1007/s40200-021-00751-0.

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

Fig. 1

Flowchart elaborating on study retrieval and inclusion in the meta-analysis. RCT: randomized controlled trial

Fig. 2

Risk of bias graph: review authors’ judgements about each risk of bias item presented as percentages across all included studies

Fig. 3

Risk of bias summary: review authors’ judgements about each risk of bias item for each included study

Fig. 4

Forest plot evaluating the impact of yoga on (a): fasting glucose; (b): glycated haemoglobin (Hba1c); (c): post-prandial glucose; (d): total cholesterol; (e): triglycerides; (f): low density lipoprotein cholesterol. 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