Does sleep affect insulin effectiveness?

My husband is a type I diabetic, a complication of pancreatitis he suffered a decade ago. His believes his insulin is not working at night when he sleeps. Can this be explained why insulin that works during the day does not seem to work at night?

[WaveRider]

There isn’t enough information in your post to provide an appropriate answer. First, you posted on the t2 forum not the t1 forum [named juvenile t1]. Secondly, what makes your husband believe he is not getting enough insulin during sleep hours? Symptoms? What are his bedtime and morning levels? Any recent change to his bolus [insulin dosage]? Is his bolus fast acting or basal rate [insulin pump, continuous supply]? Has he discussed his concerns with his doctor?  

It is always important to give as much medical information as possible, usually someone else has experienced the same problem and a search of the Internet for that symptom can produce favorable results.

[Super_sally888]

Your husband may be experiencing the dawn phenomenon.  this means that his liver dumps glucose in the early morning and makes his fasting blood sugar rise.

You need to discuss this with your husband's doctor to look at how this can be managed.