Am J Ther. 2020 Oct 6. doi: 10.1097/MJT.0000000000001152. Online ahead of print.
BACKGROUND: Intensive insulin therapy (IIT) aims at achieving near-normal glycemic control and usually uses a basal-bolus (BB) schema to mimic physiologic insulin secretion.
AREAS OF UNCERTAINTY: The treatment burden of IIT should be outweighed by improved glycemic control and reduction of chronic complications, but reviews summarizing the effects of IIT in subjects with T1DM and T2DM in glycated hemoglobin, hypoglycemia, insulin doses, and weight are limited.
DATA SOURCES: We performed a PubMed search to identify relevant randomized control trials (RCTs) comparing IIT and conventional insulin treatment in T1DM and T2DM subjects and addressing glycated hemoglobin, hypoglycemia, insulin requirements, and weight.
THERAPEUTIC ADVANCES: We have identified 11 RCTs in T1DM subjects, published years ago and very heterogenous in design. Throughout the studies there was a consistent superiority of IIT in glycated hemoglobin reduction, a higher rate of severe hypoglycemia and more weight gain in the IIT group without a clear effect on insulin doses. We have identified 2 RCTs in T2DM subjects, only one of them using a definite BB schema in the IIT group. IIT induced more hypoglycemia and better HbA1c, but not more weight gain.
CONCLUSIONS: IIT is the best option for treatment of subjects with T1DM in HbA1c reduction with a cost in the rate of hypoglycemia and weight gain. In subjects with T2DM, IIT also yields improvement in HbA1c versus conventional treatment, also at the cost of more hypoglycemic episodes, but not of higher weight gain. RCT treatment arms did not only differ in the insulin schema, but also in treatment goals, therapeutic education, and frequency of clinical visits among other characteristics. However, most evidence was gained using a BB insulin schema in the intensive arm and it is likely that the insulin schema had a relevant contribution in the results.