Importance: The incidence and prevalence of type 2 diabetes mellitus are increasing.
Objective: To review currently available insulin therapy, as well as evidence on the use, application, initiation, and intensification of insulin in the outpatient setting.
Evidence review: Data sources included PubMed for trials and investigations in type 2 diabetes examining insulin use from January 1998 to April 2014.
Findings: The hemoglobin A1c target for most patients with type 2 diabetes is 7% but needs to be modified when there is increased risk of hypoglycemia, reduced life expectancy, extensive comorbidities, or reduced resources. Insulin therapy may be considered early or late in the disease course; adverse effects include weight gain and hypoglycemia. Basal insulin can be added to oral hypoglycemic agents (generally stopping sulfonylureas) initially, and later, prandial insulin can be added in a stepwise fashion. Insulin treatment must be individualized, and there are a number of challenges to insulin initiation and intensification.
Conclusions and relevance: Insulin can help achieve ideal hemoglobin A1c goals for patients with type 2 diabetes. Barriers such as adherence, patient preferences, clinician preferences, and resource allocation must be addressed.