Thanks for query,
With only fasting blood sugar one can not stamp diabetes
Go for fasting,Post lunch and Hb1c blod level.
Reading of all levels one can have clue about diabetes.
Hb1c level is important as it gives average 4 months blood sugar level.
Your problem of having pain on ankle may be due to osteo artheritis changes in the joint.consult orthopedic and get examined.
Ok and bye.