I'm currently working my way through the House boxset and haven't heard diabetes mentioned in the first couple of series. There was an episode where someone commented on a patients breath being 'sweet' and they referred to DKA as a symptom of the pancreas failing. All the organs were failing in turn I think (caused by something suitably bizarre for House to be called in!) as I remember shouting "her pancreas is failing!" as soon as the sweet smell was mentioned - felt good to out-diagnose House
Generally I'd rather tv over-dramatized the issues we face than played it down - it all helps to educate people that this is a serious condition etc, but I agree that sometimes they do get it a bit wrong. And there are plenty of us they could ask if they want a more accurate account!