Last week when I wrote about the variety of diabetes paraphernalia Chris and I have had around our home over the last few years, Scott E. asked about ace inhibitors. My response was what it’s always been – that they are used for high blood pressure, but I take them for the off-label use of protecting my kidneys. Yet, when I thought about it, I couldn’t answer how they are protecting my kidneys, and that bothered me. So I (someone who never took a chemistry class) did a little research, and here’s what I found:
Angiotensin-converting-enzyme inhibitors, commonly known as ACE inhibitors, are a group of medications that do exactly what their name implies: they block the enzymes that convert angiotensin. More specifically, they block angiotensin I from changing into angiotensin II.
Blah blah blah… But what does that mean?
When it comes to blood pressure, your body can sense when your blood pressure gets low and in response it produces an antidote in the form of renin, which is an enzyme that sticks itself onto angiotensinogen, which is a protein in blood plasma (liquid stuff in blood). While I cannot confirm this, I’m pretty sure that angiotensinogen may be named after a popular Latin tongue twister. When these two things (renin and Latin tongue twisters) combine, they become angiotensin I, which apparently does nothing except get inspired by angiotensin converting enzymes to become angiotensin II, which makes blood vessels narrower. When blood vessels get narrower, the pressure inside them goes up.
In addition to a boa constrictor-like effect on your blood vessels, angiotensin II causes the kidneys to retain fluid (fluid that should have been released as urine is instead becoming plasma in your blood). This increases the volume of the blood, which also makes the pressure inside the blood vessels go up.
So, the primary function of ace inhibitors is to block the angiotensin converting enzymes from turning angiotensin I into angiotensin II, essentially stopping the body from making the blood vessels narrower.
Right… but what does that have to do with my kidneys?
First the basics: kidneys clean your blood and throw the waste and extra fluid into your bladder. But when blood glucose levels are elevated, kidneys have to work harder and their filters get damaged, which often leads them to start making plans for early retirement. This is when protein gets released into your urine and is known as microalbuminuria (because that’s so much easier to say than “protein in your pee”?). This is why many of us with diabetes have to pee into a cup every now and again (or worse, collect 24 hours worth and store it in the fridge. Ew!).
Back to ace inhibitors: when they are at work, blood vessels are more relaxed and blood flows through them more easily (I imagine this to be like tubing vs. white water rafting, but I don’t do water sports, so that might be a bad analogy). This includes the blood vessels that take blood to the kidneys for cleaning, but the lower pressure in these vessels means there is also lower pressure in the filtration (or cleaning) process. This is a good thing. Ace inhibitors also increase the surface area for filtration, allowing the kidneys to do their jobs more easily. This is another good thing.
These good things, combined with the lowered blood pressure, are what protect the kidneys from diabetes-related damage. Taking an ace inhibitor is a preventative measure for those cute little bean-shaped organs that magically separate your pee from your blood.
So maybe you learned something today? I certainly did. Thanks goes out to the innumerable sources I consulted while writing this piece.