Diabetes is a matter of concern for most long-term care insurers, but many diabetics are approved for coverage. The results of their decision can depend on several factors.
is Type 1 diabetes, some insurers will accept insulin use that is under 100 units a day, but in many cases under 50 - 60 units will be required instead. They will also require an A1C (blood sugar test) score under 8.0 in most cases.
If it is Type 2 diabetes, The A1C test score will be the determining factor as long as most other health conditions are well-controlled.
If diabetes of any type is found in conjunction with either smoking or vascular disease, kidney disease, or significant heart disease, an application will most often be declined.
I have had many diabetics approved with various carriers though, and I recommend that you consult with an experienced long-term care insurance agent who is familiar with underwriting procedures to get a better idea of whether your husband's specific condition is insurable or not.