Does is really matter that my husband's diabetes makes him moody sometimes... versus just being grumpy?

My husband's diabetes tends to make him grumpy when his sugar goes high. I always have this in the back of my mind when he acts upon his mood and says inconsiderate things... I wonder to myself ~ I know that his sugar must be high cause he always acts this way when it's high...or does it really matter WHY he is moody and grumpy and acts upon these moods. Is it a "Forever Forgiveness" factor for him since he's diabetic?? or does he get held accountable for his behavior?? He's never mean or nasty... it's just his attitude that changes and I find myself making excuses for him...to the point of telling our friends/famiy that are over to visit that he's not feeling well... Seems that there must be a balance to be made here with forgiveness and accountability.