What is insulin resistance?

Yesterday, my husband felt severe pain in his feet. He sensed his blood sugar level had shot up. When he checked, the glucometer showed 334. My God! He cried out that he could not believe it. He has been under strict diet.

He has been eating only red rice, avoiding sugar in coffee though he could not resist bananas. He suspected that his insulin is not doing its job. He increased the dosage to almost double. Still, the sugar level did not relent.

I wonder how diabetic patients feel if they find their insulin is outdated. What will be the symptoms if one use expired insulin?

He is still writing in pain because of his diabetic feet. I advised change of diabetic tablets that he takes after food. He injects the insulin before food, twice a day. Is she showing resistance to insulin?

I am worried!