Evolution of diabetic ketoacidosis in gross obesity.
Glucose tolerance and insulin responses have been examined over extended periods in severely obese, but otherwise healthy, subjects. Three significant points emerge from this study. First, it was shown that obese, supposedly ketosis resistant, subjects may deteriorate in a brief time span from a state of normal glucose disposal and adequate or increased insulin responses to insulin-deficient diabetes, culminating in ketoacidosis. Unusually high blood glucose levels complicating the ketoacidosis in two patients suggest hyperosmolarity obesity and added risk factor in severely obese diabetics. It appears that, after long-standing obesity and after years of hyperinsulinemia, a large weight gain due to prolonged overeating may impose an excessive challenge to islet cells of marginal competence. Such an event by itself or a superimposed stress or both may then cause acute insulin deficiency and/or insulin resistance leading to diabetic ketoacidosis. Hyperosmolarity may be exacerbated in the obese with cessation of food intake due to large losses of salt and water. Second, many symptoms and manifestations of hyperphagic obesity are similar to the early functional abnormalities of decompensated diabetes. The advent of the critical phase of uncontrolled diabetes, therefore, fails to alarm the obese patient and may escape timely recognition by the physician. Third, technical and mechanical difficulties due to severe obesity are apt to cause critical delays in therapy. These factors, when added to coexisting hyperosmolarity and ketoacidosis, probably account for the high mortality in these patients.