Why are hypertension and diabetes patients at high risk of severe COVID-19?


Retrospective analysis of COVID-19 patient history showed that 12-22% and 23-30% of severe COVID-19 patients also had diabetes and hypertension, respectively (Guan et al., 2020; Yang et al., 2020; Zhang et al., 2020). This and other reports suggest that hypertension and diabetes are associated with a high risk of severe COVID-19 (Fang et al., 2020; Diaz et al., 2020).

The link between hypertension, diabetes and SARS-CoV-2 is angiotensin-converting enzyme 2 (ACE-2). ACE-2, expressed on lung, intestine, kidney and blood vessel epithelial cells, is one of the co-receptors SARS-CoV2 uses to infect cells. Levels of ACE-2 are higher in diabetes and hypertension patients compared to “healthy” individuals. This is due to the natural pathogenesis of the diseases, and treatment of these patients with either ACE-1 inhibitors or angiotensin-receptor antagonists, which further increases ACE-2 levels (Fang et al., 2020; Diaz et al., 2020). Based on this, researchers hypothesise that high levels of ACE-2, as observed in diabetes and hypertension patients, facilitate increased viral entry and replication leading to severe disease.

Interestingly, some researchers suggest treating severe COVID-19 with angiotensin receptor blockers (ARBs). At first, this may seem counterintuitive, however, they suggest treating with ARBs will increase ACE-2 which will then lead to increased levels of vasodilator angiotensin 1-7, reducing SARS-CoV2 pathogenesis (Gurwitz et al., 2020). This hypothesis is yet to be tested and proven.

Article by Cheleka AM Mpande


International Union of Immunological SocietiesUniversity of South AfricaInstitute of Infectious Disease and Molecular MedicineScience Education PrizesElizabeth Glazer Pediatric Aids Foundation