Effects of Stem Cell Therapy on Diabetic Mellitus Erectile Dysfunction: A Systematic Review and Meta-analysis

Stem cell is considered a potential therapy for treating erectile dysfunction (ED), including diabetic mellitus erectile dysfunction (DMED), which was investigated in some preclinical studies. Several trials introduced stem cell into clinical practice, but divergences emerged.To further investigate the therapeutic effects of stem cell on DMED in preclinical studies and investigate some possible factors that influence curative effects.The literature research was conducted in Web of Science and PubMed to retrieve studies utilizing stem cell to treat DMED. Revman 5.3 was used to perform subgroup analysis of intracavernosal pressure/mean artery pressure (ICP/MAP) and structural changes. Publication bias was assessed with Egger's test, funnel plot, and sensitivity analysis by Stata 15.0.The ICP/MAP and structural changes before and after stem cell treatment.Of 2,115 studies retrieved, 23 studies are eligible. Plus 10 studies from a meta-analysis published in 2016, 33 studies were enrolled. Pooled analysis showed that stem cell ameliorates damaged ICP/MAP (WMD 0.26; 95% CI 0.23-0.29; P < .001) and structural changes induced by diabetes. Subgroup analysis indicated that adipose-derived mesenchymal stem cell (ADSC) may have better efficacy than bone marrow-derived mesenchymal stem cell (BMSC) (χ2= 4.21, P = .04; ADSC WMD 0.28, 95% CI [0.24-0.32] vs BMSC WMD 0.22 95% CI [0.17-0.26]). Transplantation type, diabetes type, and cell number make no difference to curative effects. Gene modification and therapy combination proved promising in improving the therapeutic effects of stem cell.The evidence reminded that ADSC may be prior to BMSC in clinical trials and autotransplantation is probably not compulsory in the clinical practice of stem cell.The study number and sample size are large enough. However, high degree of heterogeneity remains after subgroup analysis.This meta-analysis suggests the efficacy of stem cell therapy for DMED and the possible superiority of ADSC over BMSC in erection restoration and structure renovation.