Integrative Medicine and Conventional Medicine Perspective – The Corona Virus ACE-2 Debate
COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The reported fatality rate is around 2.3%, but it is higher in the elderly and patients with comorbidities. Comorbidities are two or more health problems that are present at the same time; these are more common in older age groups. These are challenging times for Integrative Medicine and Conventional Medicine doctors.
The renin-angiotensin-aldosterone system (RAAS) plays a significant role in influencing cardiac output and arterial pressure. As the name implies, there are three essential components to this RAA system:
2) Angiotensin; and
Renin, which is released primarily by the kidneys, stimulates the formation of angiotensin in blood and tissues, which in turn stimulates the release of aldosterone from the adrenal cortex. Aldosterone regulates blood pressure by increasing sodium and potassium. Therefore, inhibition of RAAS is beneficial in patients with hypertension, cardiac disease and diabetes.
Angiotensin-Converting Enzyme (ACE) inhibitors and Angiotensin-receptor blockers (ARBs) are two different types of drugs that treat hypertension but in different ways. The ACE inhibitors such as Fosinopril, Benazepril, Ramipril, Captopril,Lisinopril stopsAngiotensin-I from being converted to Angiotensin-II. Blocking the production of Angiotensin-II results in relaxation of blood vessels and decreased blood pressure.
Angiotensin-receptor blockers (ARBs) such as losartan, valsartan and irbesartan, also work on the same pathway but they block Angiotensin-II from binding to receptors on the blood vessels. This also results in blood vessel relaxation and a decrease in blood pressure.
Integrative and Conventional Medicine Perspective – The Science
There have been recent research papers that have posed the question that all integrative medicine and allopathic doctors need to consider.
SARS-CoV-2 is known to bind to Angiotensin-Converting Enzyme 2 (ACE2) receptors in the lower respiratory tracts of infected patients resulting in viral pneumonia and potentially fatal respiratory failure within 10-14 days.
Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are commonly prescribed medications for the treatment of heart attacks, high blood pressure, diabetes and chronic kidney disease. The recent research papers have highlighted a potential issue concerning Covid-19, i.e., as these patients who are on this course of medications have increased numbers of ACE2 receptors in their lungs. The researchers have now hypothesised that there might be an increased rate ofbinding of the coronavirus S proteins which may result in further disease complications. As the virus makes its way into cells, it “hijacks” cells, and replicates itself. It then kills the cells and spreads.
While this is a hypothesis with little or no clinical evidence, a risk-management approach in conventional and integrative medicine sector should still be utilised i.e. closer monitoring of patients who take ACE-2 increasing drugs is recommended.
However, some conventional and integrative medicine doctors and even patients through social media influenceshould avoid knee-jerk reactions such as ceasing ACE inhibitors; this could be dangerous, resulting in a rapid increase of blood pressure. Some scientist and doctors have expressed concerns that ACE-2 is expressed in high levels in the kidneys, which makes it a target for SARS-Cov-2. However, ACE-2 receptors reside on the apical membrane,but it is unclear how the virus can gain access to this area.
Furthermore, there is the mediation of serine protease to consider, and previous animal study that support the upregulation of ACE-2 receptor is unknown in human and this further complicates this issue
Advice for Integrative Medicine and Allopathy
So, the advice is to follow the guidelines from the European Society of Hypertension,Hypertension Canada, the Renal Association(UK) to name but a few that recommend the continuation of ACE-2 and ARB’s for hypertensive patients, i.e. more research is required and in the interim patients should not stop taking blood pressure medications. Some studies indicate that ACE inhibitors may reduce the risk of pneumonia in the elderly.
The great thing about this discussion which has polarised some of the medical and scientific community is that when designing a suitable vaccine or anti-viral one will need to consider the effect on ACE-2 receptors.