Applied nutritional investigation Breath acetone predicts plasma ketone bodies in children with epilepsy on a ketogenic diet

Objective: The high-fat ketogenic diet has long been used to treat refractory childhood seizures, but whether there is a relation between the degree of ketosis and effectiveness of seizure control remains unclear. Frequent measurements of plasma ketones are difficult in children so the goal was to determine the utility of breath acetone as a marker of systemic ketosis and seizure control in children given the ketogenic diet because of seizures refractory to medication. Methods: In experiment I, breath acetone and plasma ketones were assessed every 2 h during an 8-h test day in seven children. In experiment II, a preliminary assessment of the possible relation between breath acetone and seizure frequency was made over 14 d in five children and one adolescent on the ketogenic diet. Results: Breath acetone was positively and curvilinearly related to plasma acetone (r 2 0.99, P 0.0001), plasma acetoacetate (r 2 0.89, P 0.0001), and plasma -hydroxybutyrate (r 2 0.94,