Effects of long term anti epileptic drugs on serum vitamin D levels and bone profile in a cohort of Sri Lankan children

Abstract

Aims To demonstrate association between Vitamin D levels and AED usage. To demonstrate effects of long term antiepileptic drug use on bone metabolism-eg: Serum alkaline phospha-tase (ALP), calcium. Method A retrospective cohort study was performed on 205 children aged 1−12 years presented to a tertiary care hospital in Sri Lanka;119 with epilepsy, exposed to AEDs more than 2 years and 86 who are unexposed to AED. Vitamin D levels and bone profile were analyzed by che-miluminescent auto analyzer and photometric methods respectively. The prevalence of Vitamin D deficiency (< 20ng/ml) among children exposed and unexposed to AED was compared. Among exposed the effect of AED combinations on Vitamin D deficiency were assessed. Similarly bone profile was compared in the two groups. Results A higher proportion of children on AED were deficient in Vitamin D (53.7%) compared to children who are not on AED (45.3%) (p=0.233). Difference of Vitamin D deficiency among those on poly AED therapy (59.5%) and single AED (50.6%) were non-significant (p=0.353). Similarly, differences of Vitamin D deficiency in those on Carbamezapine mono therapy (50% n=18/36) and Sodium Valproate mono therapy (60.7%; n=17/27) were non-significant (p=0.4). The mean ALP among children on AED was significantly higher (599.4 ±178.96) compared to children not on AED (420.6±152.59)(p=0.044).The mean serum calcium among children exposed to AED (2.39+0.15)and those not exposed to AED (2.36+0.17) were similar (p=0.34). Conclusions Vitamin D deficiency was not significantly associated with long term AED use in children with epilepsy. Being on polytherapy over monotherapy or being on carbame-zapin over sodium Valproate was not associated with Vitamin D deficiency. However a significantly higher than normal levels of ALP was associated with long term use of AED which needs further evaluation.