I had unstable blood sugars
@AnneRay, although I am quite a few years younger than your husband. My blood sugars would bounce around all over the place with significant hypo events , dropping into the 2’s mmol/ls and rises around 14-15 mmol ls . At one point I had to carry something sweet with me as my blood sugars would just plummet. I use Libre cgm’s, the low sugar alarm would regularly go off in the night. My Dr said I had labile blood sugars, likely due to me having coeliac. So Coeliac disease, is an autoimmune disorder whereby my immune system attacks the villi in my small intestines. It’s a systemic disease that causes malabsorption issues. I am also lactose intolerant. I cannot consume dairy, not so much old cheese and yoghurt, but milk, cream, ice cream, young cheeses etc. if I drink regular milk, a part from the digestive distress I would get, because of the lack of the enzyme lactase , my body would not digest the milk sugars (lactose). This means if I drank a pint of regular milk no milk sugars would enter my blood stream so I would not see any rise in my blood sugars. Where am I going with this? My Food malabsorption issues made my blood sugars bounce around. Some medications can do this too.
Malabsorption issues as well as Medications can have an impact on blood sugars being unstable. There may be other issues that cause blood sugar instability , the pancreas’ beta cells, possibly.
I am no dr, so please don’t take this as medical advice, but these were the things that had an effect on my blood sugars. My blood sugars are more stable now as I have gone 100% gluten free and my small intestines have healed somewhat.