hi Edgar, this was a huge issue for me some years ago, and a reason I joined TuDiabetes. I've made some progress by paying strict attention to rotation. I got lots of good advice when I posted this discussion
I also keep a log of my sites, and don't go within a square inch of a site within a 30 day period.
You pretty much nailed it, Edgar. Scar tissue prevents the insulin from diffusing under the skin so it does not get where it needs to go. That's a big reason to rotate sites and avoid scar tissue whenever you can.
Scar tissue builds up as your body deposits collagen at the site of an injury. Normally, your body will reabsorb the collagen as the wound heals, but repeated injury to quickly at the same site can leave a build up of collagen. As others have noted, this can impede the absorption, but even worse, you may end up having a very uneven absorption. This variability is also a big problem, on day your bolus just doesn't work and the next you have a hypo. I am a firm believer in the ability of our bodies to heal. Even Richard157 who is a Joslin 50 year medalist talks about given parts of his body a time to rest and recover. These problems can be even worse with a pump. Marie's advice to really work hard to widely rotate injection sites is very wise indeed.
Thanks for reply. My doubt is what happen with the insulin that to inject in the scar?. Disappear??
I don't really have a good explanation for you. It is complicated. Perhaps a good way of think about it is that insulin breaks down over time, so if it is delayed and impeded in getting absorbed, it will end up having less of an effect.
I always wonder about that also, Thanks Brian
When you inject insulin sub Q it must saturate the body so some of it can be used.The body starts using it and removing it removing it as soon as it reaches the blood stream. If it is not quickly adsorbed it will not effectively offset a spike in blood sugar. Scar Tissue has poor blood flow so it has poor absorption quality's.
My Dr. told me to stop injecting in the areas where scar tissue had built up as she said it was not absorbed as efficiently there. Once I started using other areas and rotated the shots a little more I managed to take a little less of the insulins which was nice.