tetano
Editor, Senior Moderator
J Clin Med
. 2020 Dec 7;9(12):E3962.
doi: 10.3390/jcm9123962.
Novel Molecular Evidence Related to COVID-19 in Patients with Diabetes Mellitus
Yu-Huang Liao[SUP] 1 [/SUP], Jing-Quan Zheng[SUP] 2 3 4 [/SUP], Cai-Mei Zheng[SUP] 5 6 7 [/SUP], Kuo-Cheng Lu[SUP] 8 [/SUP], You-Chen Chao[SUP] 9 10 [/SUP]
Affiliations
Abstract
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly evolved into a global pandemic. The hyperglycemia in patients with diabetes mellitus (DM) substantially compromises their innate immune system. SARS-CoV-2 uses human angiotensin-converting enzyme 2 (ACE2) receptors to enter the affected cell. Uncontrolled hyperglycemia-induced glycosylation of ACE2 and the S protein of SARS-CoV-2 could facilitate the binding of S protein to ACE2, enabling viral entry. Downregulation of ACE2 activity secondary to SARS-CoV-2 infection, with consequent accumulation of angiotensin II and metabolites, eventually leads to poor outcomes. The altered binding of ACE2 with SARS-CoV-2 and the compromised innate immunity of patients with DM increase their susceptibility to COVID-19; COVID-19 induces pancreatic β-cell injury and poor glycemic control, which further compromises the immune response and aggravates hyperglycemia and COVID-19 progression, forming a vicious cycle. Sequential cleavage of viral S protein by furin and transmembrane serine protease 2 (TMPRSS2) triggers viral entry to release the viral genome into the target cell. Hence, TMPRSS2 and furin are possible drug targets. As type 1 DM exhibits a Th1-driven autoimmune process, the relatively lower mortality of COVID-19 in type 1 DM compared to type 2 DM might be attributed to an imbalance between Th1 and Th2 immunity. The anti-inflammatory effects of dipeptidyl peptidase-4 inhibitor may benefit patients with DM and COVID-19. The potential protective effects of sodium-glucose cotransporter-2 inhibitor (SGLT2i), including reduction in lactate level, prevention of lowering of cytosolic pH and reduction in pro-inflammatory cytokine levels may justify the provision of SGLT2i to patients with DM and mild or asymptomatic COVID-19. For patients with DM and COVID-19 who require hospitalization, insulin-based treatment is recommended with cessation of metformin and SGLT2i. Further evidence from randomized or case-control clinical trials is necessary to elucidate the effectiveness and pitfalls of different types of medication for DM.
Keywords: Innate immunity; angiotensin-converting enzyme 2; coronavirus disease 2019; diabetes mellitus; hyperglycemia; renin–angiotensin–aldosterone system; severe acute respiratory syndrome coronavirus 2.
. 2020 Dec 7;9(12):E3962.
doi: 10.3390/jcm9123962.
Novel Molecular Evidence Related to COVID-19 in Patients with Diabetes Mellitus
Yu-Huang Liao[SUP] 1 [/SUP], Jing-Quan Zheng[SUP] 2 3 4 [/SUP], Cai-Mei Zheng[SUP] 5 6 7 [/SUP], Kuo-Cheng Lu[SUP] 8 [/SUP], You-Chen Chao[SUP] 9 10 [/SUP]
Affiliations
- PMID: 33297431
- DOI: 10.3390/jcm9123962
Abstract
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly evolved into a global pandemic. The hyperglycemia in patients with diabetes mellitus (DM) substantially compromises their innate immune system. SARS-CoV-2 uses human angiotensin-converting enzyme 2 (ACE2) receptors to enter the affected cell. Uncontrolled hyperglycemia-induced glycosylation of ACE2 and the S protein of SARS-CoV-2 could facilitate the binding of S protein to ACE2, enabling viral entry. Downregulation of ACE2 activity secondary to SARS-CoV-2 infection, with consequent accumulation of angiotensin II and metabolites, eventually leads to poor outcomes. The altered binding of ACE2 with SARS-CoV-2 and the compromised innate immunity of patients with DM increase their susceptibility to COVID-19; COVID-19 induces pancreatic β-cell injury and poor glycemic control, which further compromises the immune response and aggravates hyperglycemia and COVID-19 progression, forming a vicious cycle. Sequential cleavage of viral S protein by furin and transmembrane serine protease 2 (TMPRSS2) triggers viral entry to release the viral genome into the target cell. Hence, TMPRSS2 and furin are possible drug targets. As type 1 DM exhibits a Th1-driven autoimmune process, the relatively lower mortality of COVID-19 in type 1 DM compared to type 2 DM might be attributed to an imbalance between Th1 and Th2 immunity. The anti-inflammatory effects of dipeptidyl peptidase-4 inhibitor may benefit patients with DM and COVID-19. The potential protective effects of sodium-glucose cotransporter-2 inhibitor (SGLT2i), including reduction in lactate level, prevention of lowering of cytosolic pH and reduction in pro-inflammatory cytokine levels may justify the provision of SGLT2i to patients with DM and mild or asymptomatic COVID-19. For patients with DM and COVID-19 who require hospitalization, insulin-based treatment is recommended with cessation of metformin and SGLT2i. Further evidence from randomized or case-control clinical trials is necessary to elucidate the effectiveness and pitfalls of different types of medication for DM.
Keywords: Innate immunity; angiotensin-converting enzyme 2; coronavirus disease 2019; diabetes mellitus; hyperglycemia; renin–angiotensin–aldosterone system; severe acute respiratory syndrome coronavirus 2.