Thanks for the thoughtful discussion! Actually, 15 years ago velosulin came out and it offered an alternative to Regular. When I used Regular I had regular site deterioration problems that disappeared with the Velosulin. I also have those problems, just a little more quickly, when I use pure Humalog and they also disappear with Velosulin or slow down by 4-5 days with a mix of H and V. I'm not quite sure what that tells us except that whatever is different about Velosulin must help it do better.
Mary Jean, I agree. My current "best guess" is that there are two
seperate problems here:
1) Humalog can occasionally and randomly go off when stored under less
than ideal conditions. This doesn't always happen, but happens much more
readily than with Regular/Velosulin
2) Some people find that sites go off much faster with Humalog. Again,
this happens for some and not others.
You can test which is happening by changing the infusion set, but
keeping exactly the same insulin in the cartridge. If the bg's go backto
normal, the site was giving the problem. If the bg's remain high, it is
the insulin that needs replacing.