Bone health, intellectual disability and epilepsy: An observational community‐based study

OBJECTIVES: Intellectual disability (ID) and epilepsy are independent risk factors for osteoporosis. Diverse predisposing factors influence this, for example in ID, genetics and poor nutrition and in epilepsy, anti‐seizure medication (ASM). Around 25% people with ID have epilepsy, majority treatment resistant. ASMs polypharmacy is common. However, little is known about the bone‐related characteristics of this vulnerable group. A prospective observational cohort study of bone profile across a community ID Epilepsy service was undertaken to understand this. MATERIALS & METHODS: Participants were on minimum 2 years of ASMs. Baseline demographics, epilepsy data, bone metabolism biomarkers, bone mineral density (BMD) and vitamin D levels were collected. Doses needed to correct vitamin D insufficiency/deficiency were calculated. RESULTS: At baseline, of 104 participants, 92 (90.2%) were vitamin D insufficient/deficient. Seventy‐six (73.1%) had a DEXA scan, 50 of whom—in the osteopaenic/osteoporotic range. DEXA scores between ambulant and non‐ambulant patients were significantly different (p = .05) but not for ID severity. A high alkaline phosphatase (ALP) predicted lower vitamin D levels. Borderline significance (p = .06) in calcium levels between normal and high ALP was identified. There were no significant associations between parathyroid hormone, inorganic phosphate and magnesium levels, with vitamin D status or DEXA hip T‐scores. Normalizing vitamin D levels (mean 101.4 nmol/L) required an average of 1951IU cholecalciferol daily. CONCLUSIONS: Vitamin D deficiency is highly prevalent in people with ID and epilepsy treated with ASMs impacting likely on their bone health. Screening with vitamin D levels, ALP and DEXA in this group should be pro‐actively and routinely considered.