Abstracts

Rationale: Despite increasing use of modified Atkins diet (MAD) in adult patients with drug- resistant epilepsy, the effects of such diet on endocrine functions are largely unknown. The aim of this study was to investigate whether use of MAD for 3 months may influence thyroid function. Methods: A total of 53 adults (mean age 37.9 years, women/men: 33/20) with drug-resistant epilepsy (47 focal, 6 generalized) were recruited from a tertiary referral epilepsy center. They used MAD for 12 weeks. The diet allowed maximum 16 grams of carbohydrates daily. Adherence to the diet was ensured by measuring blood ketosis in hospital stays after 4 and 12 weeks, and daily urine ketosis was recorded at home every evening. The patients were enrolled from March 2011 to March 2017.Thyroid function was assessed by measuring T3, rT3, fT4 and TSH before diet start and after 12 weeks on the diet in venous blood collected between 8 and 10 am after an overnight fast.None of the patients had abnormal thyroid function at baseline. Results: The changes in T3, rT3, fT4 and TSH after 12 weeks on MAD are shown in table 1.  Conclusions: Thyroid hormone levels were significantly altered after 12 weeks on MAD with a reduction in T3 and increase in fT4. In addition, a tendency to increased TSH was observed. This might imply reduced conversion from fT4 to T3 and not increased degradation from T3 to rT3. The reduced level of T3 and increased level of fT4 were within reference values. However, our findings underline the importance of careful monitoring of thyroid hormone levels when modified Atkins diet is used as treatment in adult patients with drug-resistant epilepsy. Funding: No funding