title: Efficacy and safety of oral insulin compared to subcutaneous insulin: a systematic review and meta-analysis.
abstract: BACKGROUND
  A systematic review and meta-analysis of interventional studies was conducted to compare the efficacy and safety of oral insulin versus subcutaneous (SC) insulin in diabetic patients.
  
  
  METHODS
  Medline, Scopus, ISI Web of Knowledge and Cochrane Central Register of Controlled Trials were searched. Two independent reviewers evaluated studies for eligibility and quality and extracted the data. The primary outcomes were fasting blood glucose (FBG), 1h and 2h postprandial blood glucose, HbA1c, AUC of insulin, C max and T max of insulin, and T max of glucose infusion rate. Secondary outcomes were adverse events.
  
  
  RESULTS
  Eleven studies (n = 373) met the inclusion criteria. Meta-analyses showed that there is no significant difference between oral and SC insulin in controlling HbA1c, FBG, 1 and 2 h postprandial blood glucose and producing C max of insulin (P > 0.05); however oral insulin had faster action as indicated by the shorter T max, compared to SC insulin (P < 0.05). The most included studies were varied in their methodological quality.
  
  
  CONCLUSIONS
  This systematic review and meta-analysis showed that oral insulin is comparable to SC insulin with regard to glycemic efficacy and safety. However, is necessary to conduct additional studies in which oral insulin administered to large number of patients for long enough periods of time.
authors.affiliation: Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Isfahan University of Medical Sciences, 81745, Isfahan, Iran.
authors.forename: V
authors.initials: V
authors.lastname: Akbari
authors.affiliation: Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Isfahan University of Medical Sciences, 81745, Isfahan, Iran.
authors.forename: F
authors.initials: F
authors.lastname: Hendijani
authors.affiliation: Department of Biostatistics and Epidemiology, Faculty of Public Health, Isfahan University of Medical Sciences, 81745, Isfahan, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Feizi
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Isfahan University of Medical Sciences, 81745, Isfahan, Iran.
authors.forename: J
authors.initials: J
authors.lastname: Varshosaz
authors.affiliation: Student Research Center, Faculty of Pharmacy, Isfahan University of Medical Sciences, 81745, Isfahan, Iran.
authors.forename: Z
authors.initials: Z
authors.lastname: Fakhari
authors.affiliation: Student Research Center, Faculty of Pharmacy, Isfahan University of Medical Sciences, 81745, Isfahan, Iran.
authors.forename: S
authors.initials: S
authors.lastname: Morshedi
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Isfahan University of Medical Sciences, 81745, Isfahan, Iran. mostafavi@pharm.mui.ac.ir.
authors.forename: S A
authors.initials: SA
authors.lastname: Mostafavi
mesh_terms: D000284:Administration, Oral; D002986:Clinical Trials as Topic; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control*; D007003:Hypoglycemia / Q000139:chemically induced / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use; D007279:Injections, Subcutaneous; D007328:Insulin / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use
chemical_list: D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; C517652:hemoglobin A1c protein, human
keywords: Efficacy; Oral insulin; Safety; Subcutaneous insulin