What makes you think Clinton is diabetic?
They were going to meet and see lots of folks, and schmooze, and be up and active, and somebody decided they needed "extra energy". By the time they sat down at the funeral they both had "it's passouttime" bloodsugar levels ~ that starts at about 200, and can go up to 700, milligrams per deciliter, so I'd guess 270+ for the both of them at the funeral.
Now, look at his color lately ~ guy's got some kidney problems. Probably needs little more than blood pressure medicine and some diuretics, (which gives him that gaunt look), but out on the road he's not getting enough exercise, eating too much bread, and not drinking enough water.
He's losing it fast!