Anticonvulsants impacting bone metabolism: interim results from a cross-sectional study

Background. Despite a wide range of antiepileptic drugs (AEDs) with an improved pharmacological profile, patients often experience a variety of side effects during long-trem anticonvulsant therapy, among which are osteoporotic disorders. Currently, the mechanisms of AED effect on bone metabolism remain poorly understood, which creates certain difficulties in prevention and treatment of AED-induced osteoporosis. Objective: to study bone mineral density and laboratory parameters of bone metabolism in patients with epilepsy and longterm AED administration. Material and methods. A cross-sectional study included two comparison groups: 100 adult patients with epilepsy receiving AEDs for more than 12 months and 58 healthy volunteers without taking AEDs. All participants underwent general clinical examination, computed tomography (CT) densitometry at three time points (L1, L2 and femoral neck) and laboratory tests of mineral metabolism. Results. According to CT-densitometry results, a decrease in bone mineral density was detected in the majority of participants from both study groups. While assessing an impact of osteoporosis risk factors on bone tissue in epileptic patients, low motor activity and duration of AED therapy were the most significant, which was associated with lower bone mineral density indices. The study of laboratory mineral metabolism indicators revealed significant inter-group differences in indicators such as ionized calcium, 25-hydroxy-calciferol, free thyroxine and prolactin (p(U)=0.044, p(U)=0.040, p(U)=0.001, p(U)=0.003, respectively). Conclusion. The intermediate study results showed that long-term anticonvulsant use negatively affected bone metabolism in patients suffering from epilepsy. The data obtained point at need for further in-depth study of AED therapy effect on mineral metabolism.