2.3 COVID-19 infection and diabetic
nephropathy
COVID-19 patients with comorbidities are more likely to show a more
severe clinical picture of the infection with high mortality rate. Most
of the available data highlight diabetes mellitus as one exceptional
comorbidity associated with more severe COVID-19 and mortality (D’Marco
et al., 2020). A survey done in the United Kingdom showed that out of
23,804 patients with COVID-19 dying in hospitals, 1.5% had type 1
diabetes mellitus and 32% had type 2 diabetes mellitus, with 3.5 and
2.03 times the odds of dying compared to patients without diabetes
mellitus respectively (Apicella et al., 2020). It has been observed that
patients with diabetes mellitus have a severe and fatal manifestation of
COVID-19 disease with increased ACE2 production as an adaptive response
to elevated levels of angiotensin I and II, which in effect facilitates
the entry of SARS-CoV-2 into host cells (Pal and Bhansali, 2020). This
phenomenon enhances a progressive decline in renal function in diabetic
patients characterized by an increase in serum creatinine, uric acid,
BUN, proteinuria and a decrease in estimated glomerular filtration rate
(D’Marco et al., 2020). A molecular study revealed that the enhanced
progressive decline in renal function in COVID-19 patients with diabetes
mellitus could be due to upregulation of genes that influence viral
infection pathways in diabetic nephropathy (Menon et al., 2020). For
example, proximal tubular epithelial cell (PTEC) gene, which is
co-expressed with ACE2, may exhibit cellular interplay between mechanism
that enhance viral infection and host immune responses (Menon et al.,
2020). Thus, COVID-19 increases the severity of the manifestations of
diabetes mellitus, which may then contribute to death of the diabetic
patient.