I am a DM Type II and also diagnosed OSA.
If your A1C can be documented at 6.5 or below AND KEPT THERE, there is an office issuance provision under "Conditions an AME Can Issue" or CACI
http://www.faa.gov/about/office_org...es/aam/ame/guide/media/c-cacipre-diabetes.pdf
If it is greater than 6.5, but less than 8.5, you can get an SI. Main parts are stable on your meds (such as metformin) for at least 60 days with no adverse side effects and no hypoglycemic events, no renal issues, no opthal issues (eyes), and no neuro issues especially peripheral nerves. If your primary doc is willing to write all of that up in simple simple language, and supply the blood lab paperwork to back it up, a top dawg senior AME (like Dr. Bruce Chien) and arrange to issue that in office (versus a deferral and long delay)
If it is 8.6 to 9.0, you are in the extreme yellow arc. You can still be issued, but you will get a stern lecture to bring it down immediately. 9.0 and above is edging on denial territory and is a major danger zone for general health anyway, fuggitabut flying.
With OSA, it is a special issuance. Main parts are a recent (less than 90 days) sleep study, documentations saying you have been compliant with CPAP therapy for a minimum hours each night and a minimum # of nights within a recent period), no tendency to be sleepy during the day beyond the norm, and no right heart failure on exam.
Again, if you can get all of this prepared in advance and done the way the FAA wants/expects it, an AME of the level of Dr. Bruce can issue in office.