How is it legal for law enforcement to turn applicants away for diseases like type 2 diabetes?

How is it legal for law enforcement to turn applicants away for diseases like type 2 diabetes?

The Americans with Disabilities Act requires that employers make reasonable accommodations for individuals who have disabilities. How might this requirement affect teachers, law enforcement officers, and firefighters? How is it legal for law enforcement to turn applicants away for diseases like type 2 diabetes?