19 Bangladesh Journal of Medical Science Vol. 21 No. 01 January’22 Review article/Meta analysis “Elucidation of the Shared Pathophysiology between Diabetes and COVID-19” Nagalakshmi CS 1 , Shaheen B Shaikh 2 , Santhosh NU 3 Abstract Background: COVID-19 is a rapidly spreading communicable disease worldwide. It varies widely in its spectrum of manifestations, from being mild self-limiting disease, to fulminant disease, often leading to complications and death. Diabetes is an important co-morbidity linked to severity of infection by SARS- CoV-2, which predisposes them to severe pneumonia. Poor glycaemic control is associated with worse outcomes. The disease burden of COVID-19 is continuously increasing, and with a high prevalence of diabetes, it is all the more important to understand the vital aspects of COVID-19 infection in diabetic population. Hence, we try to provide close insights into its pathophysiology, clinical characteristics, recommendations on management and prevention and possible avenues for improving disease outcomes. Methods: PubMed database and Google Scholar were searched using the key terms ‘COVID-19’, ‘SARS CoV- 2’, ‘Corona’ and ‘diabetes’. Full texts of the retrieved articles were accessed and referred. Three main mechanisms which infuence COVID-19 disease manifestation in diabetics include: (a) Entry of virus via ACE-2 receptors (b) Action through Dipeptidyl-peptidase-4, and (c) Elevation of glucose concentration in airways by elevated blood glucose.ACE-2 is expressed in alveolar epithelial cells, heart, renal-tubular and intestinal epithelia and pancreas. S-Glycoprotein on the surface of SARS-CoV-2 binds to this ACE-2 and undergoes a conformational change. This allows its’ proteolytic digestion by host cell proteases TMPRSS2 and Furin, leading to internalization of virus. Viral entry into cells triggers an infammatory response by T-helper-cells and at times, a ‘cytokine storm’, resulting in organ damage. Apart from diminishing neutrophil chemotaxis and reducing phagocytosis, by which diabetes predisposes individuals to infections, there are several specifc factors with respect to SARS-CoV2: (i) Increased ACE-2 expression (ii) Raised Furin (iii) Diminished T-cell functioning, and (iv) Increased IL-6 levels. Movement restrictions, increased stress due to social isolation and lack of physical activity further complicates the issue. It is therefore, much essential to raise awareness among front-line workers. Finally, the current situation emphasizes the need for more clinical investigation and defne best practices for optimum outcomes. Keywords: COVID-19; Diabetes; Epidemics; Pandemics; outcome; glycaemic control; ACE-2; DPP-4; cytokine storm; comorbidity; prevention Correspondence: Dr Nagalakshmi CS, Professor and Head, Department of Biochemistry, Akash Institute of Medical Sciences and Research Center, Devanahalli, Bangalore Rural, Karnataka, India. Email: csnbio@gmail.com, nagu_kolar@yahoo.co.in 1. Dr Nagalakshmi CS, Professor and Head, Department of Biochemistry, Akash Institute of Medical Sciences and Research Center, Devanahalli, Bangalore Rural, Karnataka, India. Email: csnbio@gmail.com, nagu_kolar@yahoo.co.in 2. Dr. Shaheen B Shaikh, Associate Professor, Department of Biochemistry, Yenepoya Medical College Hospital, Mangaluru, Karnataka, India. 3. Dr Santhosh NU, Consultant Neurosurgeon (Endovascular), Aster CMI Hospital, Sahakarnagar, Hebbal, Bangalore North, Karnataka, India. Bangladesh Journal of Medical Science Vol. 21 No. 01 January’22 Page : 19-23 DOI: https://doi.org/10.3329/bjms.v21i1.56323 Introduction: COVID-19 (Coronavirus Disease-2019), a disease caused by Coronavirus (SARS-CoV), has emerged as a rapidly spreading communicable disease afecting almost all countries. The disease severity varies from mild self-limiting fu-like illness, to fulminant pneumonia, respiratory failure and death. 1,2 The spread of this novel virus has reached pandemic proportions and it represents a threat by its increased morbidity and mortality, globally. 3