Effect of ketogenic therapy on resting energy expenditure and respiratory quotient in patients with intractable epilepsy

Ketogenic Therapy (KT), a treatment for intractable epilepsy (IE), involves major changes in macronutrient intake. Literature suggests patients with IE have lower resting energy expenditure (REE) compared to healthy children. To test the effect of KT on REE and respiratory quotient (RQ), we evaluated patients with IE receiving KT and patients before and 1 year after KT. REE was measured by open‐circuit indirect calorimetry. Measured REE was compared to the average of multiple prediction equations. Anthropometrics were obtained to determine growth and percent body fat. Measured REE is significantly lower than predicted both with and without adjusting for FFM (p<0.001), with a wide range in percent of predicted (range 46–89%). No effect of KT on difference between measured and predicted REE was observed, however fold change between actual calories and REE was correlated with time on KT. RQ was found to be significantly lower in patients on KT as compared to patients before (0.91 vs. 0.75, p=0.01) and was positively correlated with weight z score (r=0.6, p=0.01). Patients with intractable epilepsy have lower REE using prediction equations for healthy children independent of KT. Further studies should evaluate REE and RQ with changes in seizure activity after initiation on KT. It is unknown whether better determination of energy needs may be important for seizure control as well as growth. Supported by CTSA#1UL1RR029890