Have Diabetes?? Read This Or You Might Need To Get Your Feet Amputated!!

Diabetes and Foot Care: If you have diabetes, have you ever heard from your doctor that it's absolutely crucial that you constantly check your feet for ulcers? Have you ever wanted to know why? Ok, so an ulcer could lead to you foot needing to be amputated, but I was meaning, did you ever want to know why diabetics get ulcers in their feet? Well, the answer involves 2 main factors, blood supply and nerves. Let me break them down for you.

1^st, let's talk about your blood supply. You have a ton of blood vessels throughout your body and they have a protein in them called elastin. Elastin gives your blood vessels elastic abilities (like a rubber band) that allow them to accommodate the normal regulatory constricting and dilating without being torn apart. Elastin is full of an amino acid called Lysine. Lysine is special because it's positively charged (I'll write it like this: Lys+). As you may have learned in one of your old science classes, positively charged things repel each other. Thus, picture the structure of this protein, with lots of lysines, you get a structure like this: Lys+--Lys+. Thus, if you were to push the 2 Lysines together, their positive charges would repel, thus pushing them back to their starting positions (elasticity). Further, if you pull them apart, there are other nearby lysines that would repel them back to their original position. Anyways, in Diabetes, an excess of sugar (glucose) is in the blood and it attaches inappropriately to all sorts of proteins (thus diabetes actually damages lots of organs). If you can picture it, by having the Lys+ attach to a sugar, the lysine loses its positive charge and thus loses its elasticity. Ok, so that was a long way of saying that diabetes causes the loss of elastic properties of proteins, but I at least wanted to demonstrate why instead of just having you take my word for it. So what does this do?

Essentially, as blood vessels lose their normal elasticity, they can no longer properly change their diameters (constricting and dilating) as they're supposed to. The net result is a drop in blood flow to areas distal to (meaning further away from) the area of the damaged proteins. As you know, blood carries oxygen (on hemoglobin) and if an area of the body doesn't get enough oxygen, the tissues can die. Normally, when a part of the body does not have enough oxygen, it's EXTREMELY PAINFUL. For example, that chest pain (angina) that people with cardiovascular disease feel is because the heart muscle isn't getting enough oxygen. Thus, a lack of oxygen to tissues in the body is super painful like a wakeup call to the brain to say, "HEY, I'M NOT GETTING ENOUGH OXYGEN, I'M GOING TO DIE IF YOU DON'T DO SOMETHING ABOUT IT!!!". Further, if you think about it, which part of your body is farthest away from the main source of oxygenated blood (from the heart)? It's the feet. By the time the blood in your blood vessels get to your feet, a lot of oxygen has already been absorbed by other tissues along the way. Thus, the ulcers a diabetic gets are in the feet since they're the farthest body part away from the heart. If you suddenly grew a 20 foot long tail and you had diabetes, the tip of your tail would now be the 1^st place you'd get ulcers instead of your feet.

Ok, so we identified that the tissues in the body getting the least amount of oxygen contain the cells that are most at risk of dying (and thus causing an ulcer) and we explained why these ulcers occur in the feet. So if tissues that aren't getting enough oxygen hurt so badly, why don't diabetics feel the excruciating pain of ulcers developing in their feet? This leads us to part two, nerves.

What do nerves do? Well, they do a variety of things whether it be to pass along sensory information to the central and peripheral nervous systems and they also send motor (movement) signals from the central and peripheral nervous systems back to the tissues in our bodies. We could go on and on about nerves all day but I'm just going to focus on a few things. For one, nerves help us sense stuff and relay that information to our brain. Say for example I was a mean person and I came and punched you in your arm, after it happened, the sensory receptors for touch/pressure/pain/etc. in your arm would send signals along your nerves both to your peripheral nervous system (which would be involved in any reflex actions) and to your brain (which would make you be aware of what happened and likely make you very upset with me). Thus, nerves are important for relaying information. For example, you may know of people who have had a spinal cord injury and no longer can feel sensations from the waist down. If you took a needle, you could poke them and it wouldn't hurt them in the same manner in which it would hurt someone with an intact nerve pathway.

Well, in people with diabetes, once again, the excess sugar in one's blood has destructive effects on the nerves in a variety of ways. One such way involves simple osmosis. If you remember back to your old science classes where you learned the principles of osmosis in that a solution with more solutes (dissolved stuff) draws water towards it so as to get rid of any concentration gradients (differences between one area's concentration and another areas concentration). More or less, sugars draw water towards them just as other solutes would. Think about it, if you eat a ton of Doritos, do you not get thirsty? Why do you get thirsty? It's because your body has sensed that there's an increase in the concentration of dissolved salts and thus tells your body to take in water to dilute that concentrated environment back to a normal concentration. Thus, when you eat lots of chips and drink lots of fluids, you actually do feel bloated because you are indeed retaining water. Anyways, I digress. So in diabetics, the excess sugar (glucose) gets into the nerve cells and as we described in osmosis, wherever solutes go, water follows and brings too much water into the nerve cells and damages or kills them.

So let's recap. Diabetes causes an excess amount of sugar to be in the blood. This extra sugar 1) damages our blood vessels thus lowering the amount of oxygen that can get to our tissues which subsequently causes the development of ulcers, and 2) damages our nerves such that we are no longer able to adequately feel what would have otherwise been an excruciating pain in our feet caused by the dying flesh in the ulcer. Thus, if you have diabetes, check your feet daily. You don't want to hear the horror stories about amputated feet (and sometimes that's just if you're lucky).