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Which is more correct to say:

Diabetes patients

OR

Diabetic patients

?
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They are both correct, but the first one implies that the issue is about patients with diabetes, while the second recognizes the patients are diabetic, but the issue might be about something else.

Diabetes patients may take insulin shots.

Diabetic patients have many health concerns. Doctors of diabetic patients need to be extra careful in helping the patients avoid minor infections that can easily get out of hand.
Comments  
Both refer to people who have the disease, so I would say either could be used.
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 Englishmaven's reply was promoted to an answer.
Thanks for pointing out that nuance

Which is more correct to say? You cannot end a sentence with a colon!
For example, let us consider just a group of currently hospitalized patients.
Diabetes patients This means that at this time diabetes is the main disease of the patients and the reason they are in the hospital.
Diabetic patients? These patients are in the hospital mainly for reasons other than diabetes although they also do have diabetes.
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