The Combined Effect of Exercise Training and Cinnamon Supplementation on Glycemic Indices in Obese Individuals with Type 2 Diabetes: A Systematic Review and Meta-Analysis

Khadijeh Molaei; Mehdi Mogharnasi; Omid Zafarmand

doi:10.18502/ijdl.v26i1.21328

Khadijeh Molaei Department of Sport Sciences, Faculty of Education and Psychology, University of Sistan and Baluchestan, Zahedan, Iran
Mehdi Mogharnasi Department of Sports Sciences, University of Birjand, Birjand, Iran
Omid Zafarmand Department of Physical Education and Sports Sciences, School of Humanities, University of Yasouj, Yasouj, Iran

DOI: https://doi.org/10.18502/ijdl.v26i1.21328

Keywords: Exercise training, Glucose, Insulin, Insulin resistance, Type 2 diabetes

Abstract

Background: Obesity is one of the causes of diabetes. On the other hand, exercise along with cinnamon supplementation has been recommended as an important approach for controlling and preventing obesity and its related complications, such as diabetes and insulin resistance. Therefore, the aim of the present study is to investigate the combined effect of exercise training and cinnamon supplementation on glycemic indices in individuals with obesity and type 2 diabetes.

Methods: A systematic search of English and Persian articles published in PubMed, Web of Science, Scopus, Magiran, Google Scholar, NorMags, Irandoc, and SID databases was conducted up to January 2025. In data analysis, a randomeffects model was used to calculate the weighted mean difference (WMD), standardized mean difference (SMD) and 95% confidence interval (CI). Also, heterogeneity of studies was assessed with the I² test.

Results: In total, 11 studies involving 230 participants with obesity and type 2 diabetes were meta-analyzed. The results indicated that the combination of exercise training and cinnamon supplementation significantly reduced glucose (WMD = -13.317 [95% CI: -19.599 to -7.034]; P = 0.001) and insulin resistance (WMD = -1.098 [95% CI: -1.577 to -0.618]; P = 0.001) compared to the control group in individuals with obesity and type 2 diabetes. However, insulin levels did not show a significant change (WMD = -2.123 [95% CI: -4.333 to 0.088]; P = 0.060).

Conclusion: The results of the present meta-analysis demonstrated that the combination of exercise training and cinnamon supplementation improves glucose and insulin resistance in individuals with obesity and type 2 diabetes. These beneficial effects are not accompanied by changes in insulin levels.