title: Effect of Stem Cell Therapy on Bone Mineral Density: A Meta-Analysis of Preclinical Studies in Animal Models of Osteoporosis.
abstract: BACKGROUND
  Preclinical studies of the therapeutic role of stem cell based therapy in animal models of osteoporosis have largely yielded inconsistent results. We performed a meta-analysis to provide an overview of the currently available evidence.
  
  
  METHODS
  Pubmed, Embase and Cochrane Library databases were systematically searched for relevant controlled studies. A random-effect model was used for pooled analysis of the effect of stem cell based therapy on bone mineral density (BMD). Stratified analyses were performed to explore the effect of study characteristics on the outcomes.
  
  
  RESULTS
  Pooled results from 12 preclinical studies (110 animals in stem cell treatment groups, and 106 animals in control groups) indicated that stem cell based treatment was associated with significantly improved BMD (standardized mean difference [SMD] = 1.29, 95% Confidence Interval [CI]: 0.84-1.74, P < 0.001) with moderate heterogeneity (Cochrane's Q test: P = 0.02, I2 = 45%) among the constituent studies. Implantation of bone marrow cells, bone marrow mesenchymal stem cells, adipose-derived stem cells, and human umbilical cord blood-derived CD34+ cells, were all associated with improved BMD as compared to that in the controls (P < 0.05 for all); the only exception being the use of embryonic stem cell transplantation (P > 0.05). Egger's test detected potential publication bias (P = 0.055); however, 'trim and fill' analysis yielded similar results after statistically incorporating the hypothetical studies in the analysis (SMD = 1.24, 95% CI: 0.32-2.16, P < 0.001).
  
  
  CONCLUSIONS
  Stem cell transplantation may improve BMD in animal models of osteoporosis. Our meta-analysis indicates a potential therapeutic role of stem cell based therapy for osteoporosis, and serves to augment the rationale for clinical studies.
authors.affiliation: Department of Bone joint surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150086, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of emergency surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150086, China.
authors.forename: Changlin
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Department of Bone joint surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150086, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Bone joint surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150086, China.
authors.forename: Shuqing
authors.initials: S
authors.lastname: Tao
authors.affiliation: Heilongjiang academy of traditional Chinese medicine, Harbin, Heilongjiang Province, 150086, China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Bone joint surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150086, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Gu
mesh_terms: D000818:Animals; D015519:Bone Density; D004195:Disease Models, Animal; D010024:Osteoporosis / Q000503:physiopathology* / Q000628:therapy*; D017594:Publication Bias; D033581:Stem Cell Transplantation