Injection site: does it affect speed or efficacy of insulin?

I'm a T2, have been for almost 24 years now. Having lost my battle with my BG in the last year or two, I started with insulin in March this year - and further reduced my carbs around the same time. I'm on Insuman Comb 25, obviously a combined insulin - 18 units before breakfast, 22 before evening dinner. My BGs are pretty consistent during the day-time with modest fluctuations after eating, but always climb to their highest after my evening meal, which granted is later than ideal and a proper dinner, although still within my personal carb allowance. Hence the higher insulin at dinner time - that higher bedtime reading tends to carry through to higher than ideal in a morning.

The new regime (now off all diabetes meds) appears to be suiting me well, all of my numbers are improving steadily and I've lost 6Kg. I have my annual review tomorrow, so I will ask this question of my DN too - but I respect the experience of the members here.

Last night we went to one of our favourite spots for a picnic, as it was a gorgeous evening. This required me to administer my evening dose in the outdoors. Whilst it was totally private, I was happier attending to prepping my pen, taking my BG etc. sitting in the car, as it was breezy. So instead of injecting below the line of my belly button as instructed (I do it on the left am, right pm), I just lowered the front of my trousers and jabbed it into the exposed flesh there, whilst sitting. Trust me, I have a good enough covering of fat over the entire torso area.

I did my BG before bed and it was 7.6, a record low, this morning is was 6.5, another record low and after some exercise before lunch, it was at 5, my lowest reading for about 2 years. The only thing I did differently was the position of this particular injection.

Could the location of the injection possibly make that much difference? I've had a couple of wicked bruises when doing it on that right side, so wonder if there's some reason why this isn't proving to be a suitable location? I'm going to try the same tonight to see if the pattern is repeated.

Thanks @dancer - I suspect it's probably a coincidence, hence I want to try it again tonight.

It might also be the tension of the flesh as I was sitting down, so my belly was squished. I don't normally sit to inject as to be frank, I'm well endowed up top and my ample bosom obscures the view, so I usually stand and use a mirror.

Yes, I do vary the site each time, I look like a bloody pincushion, with a nice collection of marks, scabs and bruises. Hence it tends to be easy to see where I went last time, so I move it around. As you say, she'll surely check tomorrow and I was going to ask anyway - but she won't have the personal experience that people here have.

Thank you.

I tried the different site and technique again at dinner last night and my post meal reading was under 10 when it's usually about 11 and this morning was 6.2, another record low, although I was up earlier than usual today too. So maybe there is something to it.

I'll ask the DN this afternoon in my review.

Midriff would certainly be easier, as you say. I'm going to discuss it with her today.

I saw the DN today and she examined my belly and winced at some of my lovelier bruises. I showed her the numbers from the last couple of days and she thought it was more coincidental, in that I managed to inject more accurately in that location and had more control over the pen/needle. I showed her how I'd administered the insulin in the relative positions and she agreed, that with my shape and build, higher might give me better control. So I'm going to try the new position for a little while to see how it goes.

It is my own conclusion (I'd already felt concerns over this and was going to ask her anyway) that with the lower position I don't have as much control over my hand position and I think that I struggle keeping the needle perpendicular to the skin and when I remove it, it comes out at a slightly different angle, the retreating tip causing damage as I remove it. Hence the bruises and lumps gouged out of my belly. I'm using 6mm needles, presumably due to my build, so there's a decent amount to try and keep straight as you remove it. I feel that I can do it better in the higher position where, if nothing else, I can see it better.

Ouch - an inch! My eyes are watering for you, that must have smarted! The new pens and fine needles are only relatively new and must be so much more convenient.

I'm going to stick with the top of my tummy for a little while to get an idea of how it's working, then I might expand upwards. We discussed ensuring that I moved the site etc. and I did point out that I do have rather a lot of belly real estate to give me freedom to move around!