There were several articles about this disorder recently. It's really scary. Some people eat lots of carbs and skip the insulin, allowing the blood sugar to rise to really dangerous levels.
Because doctors don't always prescribe low carb to diabetics, there is a tendency to put weight on I guess if you keep your blood glucose within the proper range by taking insulin. For someone who wants to lose weight, not taking the insulin is like magic - you eat and you lose, except that it's terribly dangerous, as this story shows.