More likely than not, you know the best site for delivering insulin into the body: the inner chest cavity. But is it true? Not at all. When you think of the most prevalent diabetes complications — and also those most likely to occur — diabetes-related neuropathy and retinal vascular occlusion, on the shoulder, around the elbow, and on the knee occur primarily with subcutaneous injection of insulin, or injected subcutaneously by auto-injectors.
Even at the hospital, researchers report that nearly 30% of patients are injected in the belly, neck, groin, buttock, inner arm, knee, and possibly, back. Why does the stomach seem like the best site?
The stomach isn’t the most dangerous site, even at the hospital. In fact, insulin injections in the stomach tend to reduce serious hemorrhage around the eyes and the mouth.
But the best site for injections is not in the stomach, because it’s not the most common site for severe, life-threatening complications. Indeed, the top site for serious complications appears to be the injection site near the tailbone, called the soft tissue sarcoma.
As you might imagine, a discussion about the best site for diabetes-related injections is difficult, so I’m going to concentrate only on the subcutaneous injection site.
I know some healthcare professionals who’ll insist that the best site is on the inner arm or thigh — on both sides. But there’s a reason why most individuals don’t get subcutaneous injections in the arm. The best site for subcutaneous injection is on the small back, near the subcutaneous line (the skin between the collarbone and the first rib).
The following image is an example of diabetes-related blood clots that originate from an injection site in the inner forearm. On the left side, we see a pulmonary embolism (death or convulsions) resulting from a subcutaneous injection. On the right side, a separate scenario: a massive thromboembolic stroke resulting from subcutaneous injection of glucose.
What about needle safety?
But as you might imagine, people with diabetes need a safe place to receive injections and deliver medication, especially insulin.
Let’s look at needle safety because, in the United States, that’s not so simple.
According to the National Healthcare Safety Network, there were 90,810 people diagnosed with diabetes nationwide in 2012. That means that some of them need injections to ensure that their blood glucose levels don’t get too high or too low, that they don’t have difficulty functioning, and that they don’t have serious complications, including diabetic coma, amputation, and sudden death.
Most people are aware that you should avoid direct contact with a contaminated needle and that you should never inject it into a wound. However, you should also understand that many injection sites aren’t even visible to you.
According to the American Diabetes Association, there are three possible locations where people could inject insulin:
On the back.
Obviously, people with diabetes can’t inject into the stomach or anywhere near the stomach, which is extremely dangerous. So if they’re injecting medication or putting medicine into their bodies — be it insulin, pills, or another medication — and they need to access an injection site, they should not use their arms to do so, even if the drug or medication comes in a blister-pack or syringe.
What about testing?
I recently met with an adolescent diabetic patient who took insulin shots in the stomach. It wasn’t easy, because it made her stomach hurt.
In her case, she was trying to test blood glucose in the stomach. But she found that it wasn’t as simple as testing with a finger stick. While testing on the back of the hand seemed like a safer, less painful option. It simply wasn’t, because needles don’t necessarily puncture the tissue directly.
The most likely result is that the needle punctures the top layer of skin (called the epidermis) and goes into the subcutaneous tissue. Since the skin is softer than the muscle, which is on the back. It’s easy to puncture it and make the needle poke out and penetrate into the subcutaneous tissue.
In that case, testing is probably safe, since the needle isn’t in direct contact with the muscle, which is what creates pain when testing.
But what about testing on the back?
The patient was concerned because she had become concerned about using needles in her thighs. She could test in the belly, but testing that area could cause the blood to pool in the belly and be exposed to bacteria.
There’s another reason to avoid testing on the back. It’s because a different person could use that area to practice. If you practice injecting with a sterile needle in the soft tissue near your butt (or wherever), the person could actually inject you with insulin. And you’d end up with a nasty needle wound in the back. So you don’t want to test or put a needle in that area because of that possibility.