I have diabetes, and have had it for 49 years. The best thing non-diabetics can do when something like this happens, is to express their sympathy, bring flowers and cards to the hospital AND SHUT THE HELL UP ABOUT WHAT THEY THINK MAY BE THAT INDIVIDUAL'S RESPONSIBILITY FOR THEIR CONDITION. Do you think you know something about it, you who have never taken a blood glucose reading, or injected half a CC of insulin? Do you have to assess what is in your meal, and how much insulin you should take or how much of it you should eat? Do you check your feet regularly for any sign of a problem? Do you worry that when a large floater appears in your eye, you may be about to lose your eyesight? Have you ever taken your socks off at night and found your toe turning black, even though it was OK the morning before? Those things have happened to me, and people did tell me it was my own fault for not looking after myself. And I wondered how they were making out with their non-existent diabetes.
These things can be prevented? Bull! By and large, they sneak up on you a little at a time, and the best diabetes care in the world cannot prevent them. They are a condition, a result, of being diabetic. Your uncle George lived until 90 with diabetes and never had a complication in his life? He got lucky. I know people with no legs who have never taken a drink or eaten a sweet since they got the disease, and have painstakingly followed the rules. I suffer from diabetic retinopathy, heart disease, kidney disease, liver disease, neuropathy, nephropathy, arthritis, and oddly enough, depression. Still after 49 years I am holding my own. I have two legs, two eyes, and the liver and kidney problems are incipient (They may not get to be full-blown, but if I live long enough....) The other stuff is in a kind of remission, but I lose the feeling in my hands two to five times a day, the feeling in my feet is almost gone. I test my blood glucose two to five times a day, and I still get surprises in the form of unexplainable highs.
The only way to prevent all this is not to get diabetes, and if you can figure out how to do that, you can have the Nobel Prize. Before you presume to tell a diabetic that his problems could have been prevented with a little more care, ask a few diabetics what it's like to live with this godawful disease.