Some researchers believe there's a separate category to consider, that being pre pre-diabetes. In other words, even seemingly minor blood sugar anomolies can cause significant health effects. Some researchers also believe various forms of dementia could be considered to be Type III diabetes.
Apparently, blood sugar levels are extremely important, and it would seem especially for those who suffer from tinnitus. Fortunately, there's many things--such as diet--that often help significantly in controlling blood sugar levels. Combining some kind of intermittent fasting with ketogenic principles seem to be especially helpful.
In
THIS THREAD (lengthy), a man explains in detail why he thought the ketogenic diet might help his brain and his overall health, which is probably the same explanation for why it helped his tinnitus. I asked him for some details on his tinnitus, and he responded with the following reply:
I've had terrible tinnitus the entire 5 1/2 years of ME. The ME caused the tinnitus, I never had it before that. It was the worst the first two years (really loud and fairly constant, especially exploding when someone talked too loud near me or triggered by other noises), then as I moved into chronic phase it stabilized to daily periods of tinnitus with fluctuations.
Now the tinnitus is gone... seriously... completely gone within a few days (as well as a host of other symptoms). So for me and others who've done a 180 with a ketogenic diet it was the fact that my body's and brain's cells were totally malfunctioning. They were still trying to use glucose for energy from the carbs I was eating in a normal diet and a crucial part of the ME disease process is blocking it at the cellular level. Only by switching my body to fully use ketones did everything change... some of us are strong anecdotal proof of the disease process discovered by the metabolomics studies.