yea actually i was im paramedic school with a guy who was a diabetic and on a fire department..great guy..worked with him before as well..id trust him with my life.
If a department has a policy that they comply with the NFPA 1582 Medical Fitness for Duty standard, they will not hire an insulin-dependent diabetic. They do not have to hire a non-insulin-dependent diabetic unless that person can show consistent fasting blood glucose levels below 120 or a hemeglobin A1C of 8 or less. The NIDDM potential employee must also be able to show no hypoglycemic episodes within one year prior to hire.
The reason for not hiring insulin dependent (IDDM) folks as firefighters is obvious - the stresses, possibility of irregular (or no) meals, and the resulting risks of hypoglycemic episodes or insulin shock while driving apparatus, engaging in firefighting, climbing a ladder, etc. are just too risky to the person's life and health...to say nothing of the lives and health of the other firefighters.
The reason for not hiring NIDDM folks who don't have their condition under control is the increased risks of heart attacks and strokes that uncontrolled diabetes adds to the already large risks of heat-stress-induced cardiac events that firefighters already face.
If the department doesn't follow NFPA 1582, then they're gambling with the lives and health of every member, not just the potential hire with diabetes.
My recommendation is to consider work that doesn't require a firefighter physical and will let a diabetic work with less risk - EMS, law enforcement, dispatching, emergency management, homeland security...the list is still nearly endless.