For DVLA see the following
https://assets.publishing.service.g...vers-with-diabetes-treated-by-non-insulin.pdf
You do need to inform your insurance companies ( driving, hospital plan, or life assurance) since it will affect their risk and this may increase insurance premiums. However, most will not increase the premium. Not telling them may result in them not paying out if there is a claim and they find out after the event.
I am a T2D driver over 70 and I was able to renew my licence while taking Glic but they do check up on medical records or ask your doctor to confirm your statements. They will also expect to see a recent retinopathy review report and possibly an eye test. This was necessary for renewal as a pensioner but was not required while I was commuting to work.
So long as you don't need to renew you do not need to tell them except if advised by a doctor or had 2 or more hypos needing medical assistance such as a paramedic or A&E. Or you start insulin treatment.