Clinical perspectives on the frequency of hypoglycemia in treat-to-target randomized controlled trials comparing basal insulin analogs in type 2 diabetes: a narrative review

The objective of this review was to comprehensively present and summarize trends in reported rates of hypoglycemia with one or two times per day basal insulin analogs in individuals with type 2 diabetes to help address and contextualize the emerging theoretical concern of increased hypoglycemic risk with once-weekly basal insulins. Hypoglycemia data were extracted from treat-to-target randomized clinical trials conducted during 2000-2022. Published articles were identified on PubMed or within the US Food and Drug Administration submission documents. Overall, 57 articles were identified: 44 assessed hypoglycemic outcomes in participants receiving basal-only therapy (33 in insulin-naive participants; 11 in insulin-experienced participants), 4 in a mixed population (insulin-naive and insulin-experienced participants) and 9 in participants receiving basal-bolus therapy. For the analysis, emphasis was placed on level 2 (blood glucose <3.0 mmol/L (<54 mg/dL)) and level 3 (or severe) hypoglycemia. Overall, event rates for level 2 or level 3 hypoglycemia across most studies ranged from 0.06 to 7.10 events/person-year of exposure (PYE) for participants receiving a basal-only insulin regimen; the rate for basal-bolus regimens ranged from 2.4 to 13.6 events/PYE. Rates were generally lower with second-generation basal insulins (insulin degludec or insulin glargine U300) than with neutral protamine Hagedorn insulin or first-generation basal insulins (insulin detemir or insulin glargine U100). Subgroup categorization by sulfonylurea usage, end-of-treatment insulin dose or glycated hemoglobin reduction did not show consistent trends on overall hypoglycemia rates. Hypoglycemia rates reported so far for once-weekly basal insulins are consistent with or lower than those reported for daily-administered basal insulin analogs.