Abstracts

Rationale: Despite the benefits of the KD, osteopenia and fractures have been reported in long term studies (Groesbeck et al. Dev Med Child Neurol 2006;48:978 81) even with vitamin D, calcium supplementation, and a reduction in the number of anti-epileptic drugs (AEDs) used (Bergqvist et al. Am. J. Clin. Nutr. 2008;88;1678-1684). The purpose of this study is to determine the risk of fractures and osteopenia in children treated with the KD, for a minimum of 1 year, compared to a control population of children who were not treated with the KD.Methods: This was a retrospective matched cohort study of children with epilepsy treated with the KD for a minimum of 1 year between November 1998 April 2013. The control population was selected from a clinical epilepsy database and was matched for age, sex, seizure type or epilepsy syndrome and ambulatory status. Osteopenia was determined by bone mineral density using Dual energy X-ray absorptiometry (DEXA) when available, or from X-ray radiology reports.Results: 132 patients were included in the study. 66 patients were treated with AEDs and the KD (KD group) and 66 patients were treated with AEDs alone (control group). There were 32 males and 31 females in each group. 36% (n=24) of the patients in both groups were non-ambulatory. The mean age at initiation of the KD was 4.3 years (8 months -13 years) and the mean treatment duration was 4.3 years (1-10). Nine (14%) of the patients in KD group had fractures versus 5 (8%) in the control group. The rate ratio was 1.8 (p = 0.25). The mean number of fractures was 1 (range 1-15) in KD group and 1 (range 1-7) in the control group. 66.7% (n=6) of subjects with fracture in the KD group had no history of trauma. All patients (n=5) with fractures in the control group had a trauma history. In the KD group, 36% (n=24) of patients had osteopenia vs 17% in the control group. The rate ratio was 2.18, (p=0.01). All patients with fractures in the KD group had osteopenia vs 60% (n=3) in the control group. Non-ambulatory status was a risk factor for osteopenia (p<0.001) and fractures (p=0.02) in both groups. In patients treated for 1-3 years (n=26), 4% (n=1) had fractures and 20% (n=8) in patients treated for 4 or more years (n=40) (p=0.06). Osteopenia was present in 27% (n=7) of patients treated for 1-3 years and in 43% (n=17) of patients treated for 4 or more years (p=0.007).Conclusions: To our knowledge this is the first matched cohort study examining the risk of osteopenia and fractures in children with epilepsy treated with the KD. Patients treated with the ketogenic diet have a significant risk of developing osteopenia when compared with matched controls. Fractures and multiple fractures were more common in the KD group, often unrelated to trauma. The incidence of osteopenia and fractures increased with prolonged treatment of the KD. Monitoring of bone health and vitamin D and Calcium supplementation is important in this population.