Substantial early changes in bone and calcium metabolism among adult pharmacoresistant epilepsy patients on a modified Atkins diet

Objective The aim of this study was to investigate whether the modified Atkins diet (MAD), a variant of the ketogenic diet, has an impact on bone- and calcium (Ca) metabolism. Methods Two groups of adult patients with pharmacoresistant epilepsy were investigated. One, the diet group (n = 53), was treated with MAD for 12 weeks, whereas the other, the reference group (n = 28), stayed on their habitual diet in the same period. All measurements were performed before and after the 12 weeks in both groups. We assessed bone health by measuring parathyroid hormone (PTH), Ca, 25-OH vitamin D (25-OH vit D), 1,25-OH vitamin D (1,25-OH vit D), phosphate, alkaline phosphatase (ALP), and the bone turnover markers procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide collagen type 1 (CTX-1). In addition, we examined the changes of sex hormones (estradiol, testosterone, luteinizing hormone, follicle-stimulating hormone), sex hormone-binding globulin, and leptin. Results After 12 weeks of MAD, we found a significant reduction in PTH, Ca, CTX-1, P1NP, 1,25-OH vit D, and leptin. There was a significant increase in 25-OH vit D. These changes were most pronounced among patients <37 years old, and in those patients with the highest body mass index (>= 25.8 kg/m(2)), whereas sex and type of antiseizure medication had no impact on the results. For the reference group, the changes were nonsignificant for all the analyses. In addition, the changes in sex hormones were nonsignificant. Significance Twelve weeks of MAD treatment leads to significant changes in bone and Ca metabolism, with a possible negative effect on bone health as a result. A reduced level of leptin may be a triggering mechanism. The changes could be important for patients on MAD, and especially relevant for those patients who receive treatment with MAD at an early age before peak bone mass is reached.