The Role of Statins (HMG-CoA Reductase Inhibitors) on Insulin Secretion from the Islets of Langerhans: A Systematic Review

Context: Statins are administered to decrease atherosclerosis in patients with coronary heart disease. These drugs enhance the risk of diabetes by affecting islets insulin secretion. Objectives: Therefore, this systematic review investigates the effect of statins on insulin secretion of islets of Langerhans in the related original studies. Methods: A preliminary search was performed in the PubMed, Scopus, Web of Science, and ProQuest databases. The search strategy terms were statin (hydroxymethylglutaryl-CoA reductase inhibitors), insulin secretion, and islets of Langerhans. The search elements were evaluated using the Mesh term system. Limits were used to include only review articles and no limits were set on language. The quality of the method and risk of bias was assessed by its tool. Results: After removing irrelevant articles to the subject, 20 articles fulfilled the inclusion criteria. In vivo studies revealed that pravastatin and rosuvastatin increase and decrease islets insulin secretion, while atorvastatin and fluvastatin reduced this variable, and pitavastatin had no effect. The results of in vitro studies showed that pravastatin and induced both increasing and decreasing effects on insulin secretion from the pancreatic islet cells. Also, administration of atorvastatin, rosuvastatin, fluvastatin, pitavastatin, simvastatin, and lovastatin decreased islet insulin secretion in the medium. Conclusions: Pravastatin could enhance pancreatic islet insulin secretion while other statins reduced this variable. Finally, the contradictory effect of statins on islets’ insulin secretion can indicate the existence of laboratory and clinical research in this regard.