For a good resource on how you can qualify for social security disability in the US because of your diabetes you can refer to this reference from NOLO. They start off with this statement:
If your diabetes has caused medical complications or organ damage that limits your activity, you may be able to get disability benefits.
In general :
If you have uncontrolled diabetes and you have been prevented from working for at least 12 months, or you expect that you won’t be able to work for at least 12 months, then you may be eligible for Social Security disability (SSDI/SSD) benefits or Supplemental Security Income (SSI) benefits. But to qualify for disability benefits, the damage caused by your diabetes must severely limit what you can do, or you must have complications that fulfill the requirements of one of Social Security’s disability listings. Here are the major recognized listings:
Diabetic retinopathy (Listing 2.00)
Diabetic nephropathy (Listing 6.06)
Diabetic peripheral neuropathies (Listing 11.14)
Cardiovascular problems. (listing 4.02, listing 4.12, listing 4.05)
Poorly healing skin and bacterial infections (Listing 8.04)
Amputation of an extremity (Listing 1.05)
The upshot is as NOLO says:
Because Social Security’s disability listings require that the preceding complications be quite severe to qualify for disability, Social Security finds that most people who apply for disability due to diabetes do not meet a listing.
That being said, in the US Diabetes is recognized as a general disability and you are given equal protections from discrimination (as is the case in the UK). But getting preferential treatment or disability payments is an entirely different thing.