[P2-79] Environmental and genetic predictors of low bone mineral density in Malaysian children with epilepsy
Children with epilepsy (CWE) on long-term antiepileptic drugs (AEDs) are at risk of low bone mineral density (BMD). This study aimed to evaluate the prevalence and predictors of low BMD among Malaysian CWE. BMD of the lumbar spine (L1-L4) using dual-energy X-ray absorptiometry (DXA) and serum concentrations of 25-hydroxyvitamin D, parathyroid hormone, calcium and alkaline phosphatase were measured in 87 ambulant patients on AED for >1 year. Detailed assessment of physical activity, sun exposure behaviour, dietary intake, anthropometric measurements and clinical history were obtained. Eleven single nucleotide polymorphisms (SNP) in 5 genes (VDR, GC, CYP2R1, CYP27B1, CYP24A1) previously reported to be associated with vitamin D and BMD were genotyped using TaqMan assays. Multiple logistic regression analysis was performed to identify potential predictors that significantly (p<0.05) associate with low BMD. BMD measurements were categorized as “low BMD” for Z-scores ≤-2.0. Mean age of the participants was 11.8 years old and 64.4% were male. Low BMD was observed in 21.8% of the patients. In the logistic regression model, significant predictors of low BMD included AED polytherapy (>2 AED) (Odds ratio: 7.857; confidence interval: 1.03–59.96; p=0.018), wrist breadth <15th centile (OR 14.73; CI 2.21–98.40; p=0.006) and underweight (body mass index Z-score <-2.0) (OR 8.73; CI 1.17–65.19; p=0.035). None of the 11 SNPs investigated independently associated with low BMD. In this study, low BMD was highly prevalent among the Malaysian CWE on long-term AED; AED polytherapy (>2 AED), low wrist breadth and underweight independently associated with low BMD status.