This is simple, hypoglycemia is the precursor to diabetes. They are both ultimately caused by the same thing, which is too much dietary sugar/carbs.
Prior to a diabetic condition, ingested carbohydrates will cause the pancreas to spike insulin to try to control the serum glucose levels. These spikes often drive blood sugar low, which is diagnosed as hypoglycemia. In the human world we often call this a "food coma".
Over time, the constant ingestion of carbs causes frequent spikes of glucose, which causes an immediate, corresponding insulin response by the pancreas. After awhile, depending on the animal's genetics and overall health, the roller coaster of glucose spikes and insulin spikes cause the pancreas to simply wear out until it becomes unable to maintain proper glucose levels through insulin response. Welcome to diabetes.
In humans, it's all the processed food with high glycemic index carbs that has caused this epidemic in our society. If you eat low glycemic carbs, the absorption is slower, thus the conversion to glucose is more gradual allowing the pancreas to manage it with gentle releases of insulin. In dogs, with their short digestive tract and total lack of need for dietary carbs to begin with, I'd wager that the process of developing hypoglycemia and having that graduate into diabetes happens much more quickly relative to the average lifespan of a dog.
Kibble is killing your dogs people. Even grain-free kibble is loaded with carbs, usually from potatoes. Imagine eating nothing but two big bowls of Lucky Charms every day for the rest of your life. How long would it be before you developed hypoglycemia then diabetes? Most kibble is the doggie equivalent of the worst human breakfast cereals and, sadly, it is all most dogs ever eat throughout their entire lives.
For optimum health, omnivore humans should eat mostly meat and vegetables and some low glycemic carbs (like those from WHOLE grains). Carnivore dogs should eat meat (and bones/organs) and NO vegetables or carbs. Sadly, there is no kibble that is truly suitable for a dog, especially a hypoglycemic or diabetic one.