Abstract
Blood ketone bodies, serum insulin levels, and plasma free fatty acids were examined in a series of patients with "non-ketotic diabetic coma" and compared with the findings in ketoacidotic subjects. Serum insulin levels in six "non ketotic" patients ranged between 1 and 25 muu./ml. and were not significantly different from levels reported in patients with ketoacidosis. In addition, plasma free fatty acids were shown to be unrelated to the degree of ketonaemia. The investigation shows that neither the levels of serum insulin nor those of free fatty acids can explain the absence of hyperketonaemia in some cases.