Prediabetes Confused

[Barbara93]

Please can someone advise
Diagnosed hypothyroid 4 years ago well controlled. HBa1c over time has been lowest 36 and 42 once in 4 years. Recently it went from 36 to 53 in 9 months. So I stopped all sweet treats ice cream bread cakes biscuits and increased my steps. Two weeks later it is now 37. My question is can it come down so quickly? I am 7stone 6 so very slim. The only thing I had done differently is gone from GF for 4 years then got fed up. So I had gone back to more carbs could that have caused the rise. I was also low in folate and 2 months ago I took folic acid for few weeks could that have made a difference. I have checked by BS randomly recently fasting morning is 5.6 and once it was 8 after I had an all day breakfast not realising baked beans so high in carbs. Anyone had similar? I don’t know what to think now
Thanks

 

[LittleGreyCat]

Recently it went from 36 to 53 in 9 months. So I stopped all sweet treats ice cream bread cakes biscuits and increased my steps. Two weeks later it is now 37. My question is can it come down so quickly?

That doesn't seem right.
HbA1c is supposed to be an average over the last 3 months biased to the last four weeks (or so).
It shouldn't change that much that quickly.