Insulin vs GLP-1 analogues in poorly controlled type 2 diabetic subjects on oral therapy: Ameta-analysis

Abdul-Ghani M., Williams K., Kanat M., Altuntas Y., DeFronzo R.

Journal of Endocrinological Investigation, vol.36, no.3, pp.168-173, 2013 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 36 Issue: 3
  • Publication Date: 2013
  • Doi Number: 10.3275/8367
  • Journal Name: Journal of Endocrinological Investigation
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.168-173
  • Keywords: GLP-1 analogues, insulin, meta-analysis, Type 2 diabetes
  • Istanbul Medipol University Affiliated: Yes


Aim: To compare insulin and GLP-1 analogues therapy on glycemic control in poorly controlled Type 2 diabetes (T2DM) subjects failing on oral therapy. Methods: The electronic database PubMed was systematically searched for randomized controlled trial (RCT) with duration >16 weeks comparing the addition of insulin therapy vs glucagon-like peptide (GLP-1) analogues in poorly controlled T2DM subjects on oral therapy. Results: We identified 7 RCT with 2199 patients of whom 1119 were assigned to insulin therapy and 1080 received a GLP-1 analogue. Both insulin and GLP-1 analogues were effective in lowering glycated hemoglobin (HbA1c) with no statistically significant difference between the mean decreases in HbA1c. However, insulin was more effective than GLP-1 analogues in lowering the fasting plasma glucose concentration, while GLP-1 agonists were more effective in lowering the postprandial glucose concentration. Insulin therapy was associated with weight gain while GLP-1 analogues consistently caused weight loss and the difference between the mean change in body weight between the two therapies was highly statistically significant. Despite a similar decrease in HbA1c, the risk of hypoglycemia was 35% lower (p=0.001) with GLP-1 therapy compared to insulin. Compared to insulin, GLP-1 analogues caused a significant decrease in systolic blood pressure and were associated with greater rate of gastrointestinal adverse events. Conclusion/interpretation: In poorly controlled T2DM subjects on oral therapy, GLP-1 analogues and insulin are equally effective in lowering the HbA1c. However, GLP-1 analogues have additional non-glycemic benefits and lower risk of hypoglycemia. Thus, GLP-1 analogues should be considered as a treatment option in this group of diabetic individuals.