Therapeutic Effects of Stem Cells for the Treatment of Diabetes Mellitus

Stem cell therapy may be the key to diabetes mellitus. In this study, we systematically retrieved the related studies and conducted this meta-analysis to evaluate the efficacy and safety of stem cell therapy for patients with diabetes mellitus. A systematic articles search was performed for eligible studies published up to April 28, 2021 through the PubMed, Cochrane library, ClinicalTrials.gov and Chinese National Knowledge Infrastructure database. The included articles were screened by using rigorous inclusion and exclusion criteria. All analyses were conducted using Review Manager 5.4. The quality of studies and risk of bias were evaluated. A total of 9 randomized controlled trials were included with a sample size of 326 subjects diagnosed with diabetes mellitus. Stem cells therapy was superior to placebo group in all of outcomes including hemoglobin A1c (mean deviation -0.51, 95 % confidence interval 0.70 to -0.32, p<0.00001), fasting plasma glucose (mean deviation -6.64, 95 % confidence interval -11.58 to -1.71, p=0.008), C-peptide (mean deviation 0.03, 95 % confidence interval 0.02 to 0.04, p<0.00001) and the requirement for insulin (mean deviation -10.34, 95 % confidence interval -16 to -4.67, p<0.00003). There was no significant difference in reported adverse events between stem cell therapy groups and placebo groups (Relative risk 1.77, 95 % confidence interval 0.89 to 3.51, p=0.10). Our results support stem cell therapy is a safe and effective therapeutic modality for diabetes mellitus. The best therapeutic outcome was achieved with bone marrow-mononuclear stem cells and hyperbaric oxygen therapy for type 2 diabetes mellitus, while the poorest outcome was observed with autologous bone marrow-mesenchymal stromal cells for type 2 diabetes mellitus.