What does the Institute of Functional Medicine have do say?
Whether it is Covid-19, the seasonal flu, or the variety of cold virues we are exposed to year-round, an important line of defense is our immune system. The Institue of Functional Medicine recently posted this excellent article:
We were recently asked if it true that if you are taking high blood pressure medication you are at lower risk of catching the Covid-19.
There has been a lot of concern about the effects that hypertensive medications may have on a Covid-19 infection. Specifically that ACEs, like lisinopril, or ARBs like losartan, valsartan and olmesartan might increase a receptor on lung cells called AT2. Covid–19 virus gets in the lung cells through the AT2 receptor. So if there are more receptors for the virus to get in, then a person on those medications might be at greater risk for the horrible lung complication, ARDS (Adult Respiratory Distress Syndrome), where the lungs fill with fluid and they can’t breathe.
There was a special report on this question on 3/30/20 in the New England Journal of Medicine. It is not actually known that ACEs and ARBs do increase the AT2 receptors in humans. It is known that ACEs decrease angiotensin 2, a hormone that increases blood pressure. If angiotensin 2 is low the AT2 receptor gets blocked by AT1,7 resulting in vasodilation and less inflammation, this is really helpful. It is known that ARBs bind the AT2 receptor to the AT1,7 receptor with the same benefit. If angiotensin 2 is high the AT2 receptor is open and more Covid-19 can get in the cell. The elevated unbound AT2 receptors also increase vasoconstriction and pulmonary edema. Which is what happens right before COVID-19 patients get ARDS.
So the answer is there seems to be a protective effect with ACEs and ARBs to help really ill people with COVID-19. There are ongoing trials using the medications. We do not know for sure yet but there seems to be a protective effect of these medications in COVID-19.