Confused

I had a cat scan of my abdomen. I was told to NOT take my metformin until after I had a blood test.
My morning numbers before the test
127,123,109,107,104,115,120,120,116 These were about normal for me over the last year or so.
AFTER I stopped the metformin my numbers were as follows
87,94,102,110,111,105,108,102. I haven’t taken any metformin since I stopped for the cat scan. I was taking 500mg metformin er 3x per day before the test.
Why would the numbers get better?