I have Type 2 diabetes and when I got epidural blocks, mostly in my lower back, my sugars were usually okay. The numbers, when high, lasted only for a day. I’ve never had “just” a cortisone injection in my back, only in my shoulders and knees. Same results with blood glucose. I won’t take cortisone/steroids by mouth, because they make me very hyper and my blood sugars go up much more. BTW, I’m always given propyphol (sp?) when having a pain block, so I’m not awake/aware of the procedure.

I have tried it alot over the years. For fibro, the body seems to absorb it so fast that the shots only give relief for about a week. And the risk of too much steroid is huge
I no longer do trigger point injections. I do get an epidural for my low back when it locks up and it works great. I only need that 1-2 years apart.
The biggest thing you can do is work out for a strong back. Becoming a part time massage therapist really straightened my back and helped me cope with pain

The pain doctors don't make any money on writing a prescription for pain meds just shots and if you do not believe me look at this is not a bill , plus they bill you for a office visit on top of getting injections , I had them done about 3 or 4 times the steroid shots which they had no affect on my neck and the nerve burning injections which made my neck worse and I told the dr. pain management that , and I was released a month later, the 1st shots I got were in 2015 to 2018 , Google the procedure's I had broke my neck in 2010 and have 2 rods and a plate in my neck plus cervical dystonia and my cervical fused , take care and have a beautiful day

I have a an anesthesiologist that gives me injections in the "spine" and sacroiliac joint. It helps alot in the right hands and not used to often.