In my experience most insurers will increase the premium a bit for diabetics but not too much. I would suggest getting quotes from the usual suspects and Which? mag has a list of best Buys. For much older couples like me and the wife with lots of medical conditions it's worth considering some of the banks paid-for current accounts which include some very good free travel insurance. I've just updated my Lloyds account and it's travel insurance includes a whole range of medical conditions including diabetes that they accept without wanting to even be told about; saved a lot of money.