Diabetes is a prevalent, serious, and costly healthcare issue in hospitals. Recent data shows that hospital settings have three times higher rates of diabetes than the general population.1,2 Hyperglycemia during hospitalization has been unequivocally associated with adverse outcomes, including infection risk, longer stays, readmissions, and mortality.3, 4, 5, 6 Conversely, a robust body of evidence accumulated through randomized clinical trials over the years has underscored the efficacy of regulating blood glucose (BG) levels to mitigate complications.7, 8, 9, 10 Based on these data, several international professional associations have released clinical guidelines endorsing the management of hospital hyperglycemia through a multidose insulin regimen with the therapeutic target of maintaining a glucose range of 100 to 180 mg/dL.11, 12, 13, 14. The recommended method for administering insulin is a basal-bolus regimen, which involves the daily subcutaneous injection of basal insulin along with rapid-acting insulin before meals for prandial and correctional doses.11 However, the complexity of this approach and the risk of hypoglycemia have limited its application. A study of 25,813 adult patients with type 2 diabetes (T2D) found that nearly one-third received treatment solely with sliding-scale insulin (SSI).15 A 2018 Cochrane review of 1048 inpatients with T2D showed that basal-bolus insulin therapy might improve short-term glycemic control but increase the risk of severe hypoglycemia.16 Therefore, a simplified treatment that achieves glycemic control comparable to basal-bolus therapy but with a lower risk of hypoglycemia could enhance treatment adherence.

Alternative regimens to the conventional basal-bolus insulin therapy have been explored. Umpierrez et al. compared the basal-bolus scheme with a basal-plus (BP) insulin regimen, which involves the administration of a single daily dose of long-acting insulin along with correctional doses without prandial applications of rapid-acting insulin. The BP regimen showed similar results in glycemic control and frequency of hypoglycemic events to those with the standard basal-bolus therapy.17 Another option is to combine dipeptidyl peptidase-4 (DPP-4) inhibitors with insulin. The use of incretin-based therapies in hospitalized patients with diabetes is attractive because of their metabolic effects, such as increasing insulin secretion in response to glucose and decreasing glucagon secretion, resulting in better control of BG levels and a reduced risk of hypoglycemia.18,19 Clinical studies have demonstrated that DPP-4 inhibitors with basal and correctional insulin doses are as effective as basal-bolus insulin therapy.20,21 This combination can replace the prandial insulin component of the basal-bolus protocol with a lower risk of hypoglycemia and fewer insulin administrations.22,23 However, it is uncertain whether the combination of a DPP-4 inhibitor and a BP insulin regimen is superior to BP therapy alone. Hence, we conducted a randomized controlled study to investigate whether the use of sitagliptin, a DPP-4 inhibitor, in combination with a BP insulin regimen is more effective in achieving better glycemic control among non-critically hospitalized patients with T2D compared to BP therapy alone.