Abstract

ROLE OF ACE-2 IN HEALTH AND DISEASEACE INHIBITORS AND ANGIOTENSIN RECEPTOR BLOCKERS REDUCE COMPLICATIONS FROM COVID-19 INFECTION: A NARRATIVE REVIEW

Sunil J. Wimalawansa, MD, Ph.D., MBA, DSc

Abstract

Although COVID-19 can infect any human, individuals with vitamin D deficiency and consequently having a weaker innate immune system are at the highest risk of developing complications and death. In more than 80% of infected people, the disease is asymptomatic or mild. However, those with severe vitamin D deficiency, COVID-19 can have detrimental outcomes. Less than 10% of those affected by COVID-19 (SARS-CoV-2) develop severe lower respiratory tract syndrome. The elderly and those with comorbidities, such as diabetes mellitus, obesity, hypertension, and cardiovascular and renal disorders, have an inherently low angiotensin-converting enzyme-2 (ACE-2) concentrations that increase the risk COVID-19, severe complications and deaths. Vitamin D deficiency weakens the innate immune system,lower ACE-2 concentration, and delays immune responses and recovery. The latter would allow exponential viral growth, spread, and over-activate the expression of inflammatory cytokines and the renin-angiotensin-aldosterone hormonal (RAS) system. The regular intake of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) typically used for hypertension and renal protection reduces the enzyme renin, angiotensin-I and angiotensin-II concentrations. Besides, ARBs increase the expression of ACE-2 that is protective against the spread of coronaviruses. Overall evidence supports that ACE inhibitors and ARBs reduce the risk of COVID-19, associated complications, and possibly deaths. However, to achieve optimal clinical outcomes, combined approaches are necessary. Such as assurance of vitamin D and other micronutrient sufficiency, better management of chronic diseases, minimising risk factors (viral entry and exposure), adherence to public health guidelines, and early attention to symptomatic disease.

Keywords: Angiotensin; cardiovascular; coronavirus; endocrine; inflammation; innate immunity; vitamin D; pandemic; Renin; SARS-CoV-2.