Efficacies of stem cell therapies for functional improvement of the β cell in patients with diabetes: A systematic review of controlled clinical trials.

Abstract

Background & Aim This study was performed to investigate whether stem cell therapy enhances β cell function by meta-analysis with proper consideration of variability of outcome measurements in controlled trial of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) patients. Methods, Results & Conclusion Method A systematic search was performed from inception to January 2018 in PubMed, EMBASE, and Cochrane databases. Β cell function was assessed by stimulated C-peptide, fasting C-peptide, normal glycosylated hemoglobin levels (HbA1C), and exogenous insulin dose patterns. The quality of the studies were assessed by both the Cochrane Collaboration's Risk of Bias (ROB) for Randomized controlled trials and the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) for non-randomized controlled trials. Result From the selected final 15 articles, total of 16 trials were analyzed. There were 6 T1DM trials (total 153 cases) and 10 T2DM trials (total 457 cases). In T2DM patients, the changes in stimulated C-peptide, HbA1c, and exogenous insulin dose versus baseline showed a favorable pattern with significant heterogeneity in stem cell therapy. In T1DM, there was no significant difference between control group and stem cell therapy group in three indicators except for HbA1c. Most of the studies were rated as having high risk of bias in the quality assessment. Conclusion The stem cell therapy for DM patients is not effective in T1 DM but seems to be effective in improving the β cell function in T2 DM. Further verification through a rigorously designed study is warranted.