There are lots of reasons a person can have memory loss . One of the first places to start is medication side effects. I'd recommend looking your husband's meds up in our Drug Database here at WebMD. And, also post to our Diabetes community for some helpful feedback from other members.
I wish we had an expert here who could speak to your questions, but we don't at this time.
I hope you've given your doctor a call and talked to him or her about this in detail. If you haven't, that would be the place to start. He or she is going to know your history and any procedures you've had done best.