Author(s): Nasser Mikhail*, Soma Wali
Background: Limited retrospective data suggest that dipeptidyl peptidase-4 (DPP-4) inhibitors such as sitagliptin may decrease mortality in patients with type 2 diabetes hospitalized with coronavirus disease 2019 (COVID-19).
Objective: To review the strength of evidence that supports possible therapeutic role of DPP-4 inhibitors in COVID-19.
Methods: PUBMED search until October 10, 2020. Search terms included COVID-19, DPP-4 inhibitors, sitagliptin, CD26, mortality, diabetes. Retrospective studies, pertinent animal investigations and pre-print studies are reviewed.
Results: Three retrospective studies have shown that use of DPP-4 inhibitors was associated with significant mortality reduction of approximately 56-87% in patients with diabetes admitted with COVID-19. In addition, in one of these studies, the use of sitagliptin before hospitalization was associated with greater number of hospital discharges, improvement of clinical status, reduced risk of transfer to intensive care unit (ICU) and need for mechanical ventilation compared with patients who were not receiving sitagliptin. Moreover, there was significant decrease in some pro-inflammatory markers in the sitagliptin group. A small retrospective study of 9 patients who were taking a DPP-4 inhibitor prior to admission did not find any significant effect of DPP-4 inhibitors on mortality and clinical outcomes after hospitalization. Results of another small study suggested increase susceptibility to COVID-19, but not to its severity, in patients taking DPP-4 inhibitors.
Conclusions: Weak evidence derived from observational studies suggests possible beneficial effects of DPP-4 inhibitors use in patients with type 2 diabetes and COVID-19. Randomized trials are urgently needed to clarify the efficacy and safety of DPP-4 inhibitors in patients with COVID-19 with and without type 2 diabetes.
