Interventions Targeting Insulin Resistance in Patients with Type 1 Diabetes: A Narrative Review

Background and Objectives: Insulin resistance (IR) is the most important factor involved in the pathogenesis of type 2 diabetes but may also develop in type 1 diabetes (T1DM). Developing IR in patients with T1DM may generate a burden in achieving glycemic targets and may deteriorate the overall prognosis. This review aims to describe the pathogenesis of IR in T1DM, summarize the common associations of IR with other conditions in patients with T1DM, describe the consequences of developing IR in these patients, and present the interventions that target IR in people with T1DM. Results: The occurrence of IR in T1DM is multifactorial; however, it is frequently linked to overweight or obesity and sedentary lifestyle. Besides impairments in glycemic control and increased insulin requirements, the presence of IR is associated with an increased cardiovascular risk in patients with T1DM. Considering that patients with T1DM are insulin-treated, IR may be evaluated only using surrogate biomarkers, the most frequently used being the estimated glucose disposal rate. The most important interventions that are shown to be feasible in improving insulin sensitivity in patients with T1DM are lifestyle optimizations, including nutrition therapy or physical activity and pharmacotherapy with metformin, sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide-1 receptor agonists, and thiazolidinediones. Conclusions: Targeting the improvement of IR in patients with T1DM is a key element in achieving optimal glycemic control, as well as improving the overall patient's prognosis besides glycemic control.