I am so worried… Just had some blood tests… never had any complications, and I have been a T1 for 40 years now. My latest A1C is 5.3, but my Urinary Creatine is 200, and my GFR is 59… 4 months ago my GFR was 65, and my Creatine was only 122.
The readings for kidney function can at times be variable. Some things can cause high creatinine levels such as strenuous exercise right before the test. And eGFR is calculated from the creatinine. This is something to ask your doctor. You can also see a specialist (a nephrologist). It may be that you have some declining kidney function, but it may also be some variation due to exercise, a UTI or some other factor.
Seconding what Brian said . . . especially in view of your excellent A1c, there are lots of other possible factors at work. And some of them are highly variable, as he points out. You definitely want to discuss this with your doc before leaping to any conclusions.