Well, I was wrong! The vet called today and told me that his kidney levels haven't changed at all since last fall and his thyroid numbers are great and his urinalysis was "perfect". The only downside is that his diabetes is progressing - his blood sugar was almost 400 only an hour after he received his insulin (when it should be more like 200 ideally). So we're increasing his insulin dosage and we'll check his blood sugar levels again next week.
His litter issues seem half-ok. He pees in both the main floor and basement box, but he still poops elsewhere on the main floor. I asked her about this and she asked me to bring a stool sample to test for parasites, etc. She did say his diabetes being out of whack could be causing it too, so hopefully if we can get his blood sugars regulated, the pooping on the floor will stop.

Re: Update on Sox (good news!)
Blog
Good news! I hope the increased insulin helps!
oh yay!! I have been meaning to ask you but I did not want to bring it up just in case it was bad news.
Patty and Jewels send their well wishes too...
Planning bio My DIY blog The Maine Bio
2012 Reading Challenge