Sitagliptin treatment at the time of hospitalization was associated with reduced mortality in patients with Type 2 Diabetes and COVID-19: a multicenter case-control retrospective observational study

<b>Background</b>. Poor outcomes have been reported in patients with type 2 diabetes and coronavirus disease 2019 (COVID-19), thus it is mandatory to explore novel therapeutic approaches for this population. <h2>Methods. In a multicenter case-control retrospective observational study, sitagliptin, an oral and highly selective DPP-4 inhibitor, was added to standard-of-care (e.g.; insulin administration) at the time of hospitalization in patients with type 2 diabetes who were hospitalized with COVID-19. Every center also recruited at 1:1 ratio untreated controls matched for age and gender. All patients had pneumonia and exhibited oxygen saturation lower than 95% when breathing ambient air, or were receiving oxygen support. The primary endpoints were discharge from the hospital/death and improvement of clinical outcomes, defined as an increase in at least two points on a seven-category modified ordinal scale. Data were collected retrospectively from patients receiving sitagliptin from March 1 through April 30, 2020. </h2> <h2>Results. Of the 338 consecutive patients with type 2 diabetes and COVID-19 admitted in Northern Italy hospitals included in this study, 169 were on sitagliptin, while 169 were on standard-of-care. Treatment with sitagliptin at the time of hospitalization was associated with reduced mortality (18% vs. 37% of deceased patients; HR=0.44, 95% CI: 0.29-0.66, p=0.0001), with an improvement in clinical outcomes (60% vs. 38% of improved patients, p=0.0001) and with a greater number of hospital discharges (120 vs. 89 of discharged patients, p=0.0008), compared to patients receiving standard-of-care respectively. </h2> <h2>Conclusions. In this multicenter case-control retrospective observational study of patients with type 2 diabetes admitted to the hospital for COVID-19, sitagliptin treatment at the time of hospitalization was associated with reduced mortality and improved clinical outcomes as compared to standard-of-care treatment. The effects of sitagliptin in patients with type 2 diabetes and COVID-19 should be confirmed in an ongoing randomized, placebo-controlled trial. </h2>