Ketone body kinetics in normal,diabetic, and obese humans

We have developed a model for the kinetics of acetoacetate (A) and β-OH-butyrate (B) in normal subjects. The model contains separate compartments for blood A, B, and acetone, as well as three exchange compartments. By using the model, the synthesis, utilization, and clearance rates of A and B were determined separately. We have compared the model with others that have been proposed for ketone body metabolism and have used the model to analyse studies undertaken in newly diagnosed diabetic patients and obese subjects (before and after a 2 week period of starvation). We found that in diabetic and obese individuals the synthesis of ketone bodies was higher than normal and that the fractional losses of A and B were reduced. The results suggest that ketosis develops as a result of high synthesis rates coupled with decreased fractional loss of ketone bodies. In each group the metabolism of B was altered more than A.