Bone health in adults with epilepsy and intellectual disability

[摘要] Epilepsy is more prevalent in individuals with intellectual disability (ID) compared to the general population, and this prevalence increases with increasing severity of ID. Epilepsy affects approximately 22% of people with ID, while 25% of people with epilepsy (PWE) have an ID.1 Epilepsy is associated with significantly impaired bone health including osteoporosis and bone fractures,2 while individuals with ID are at increased risk of osteopenia and osteoporosis, and vitamin D deficiency.3BONE HEALTH AND EPILEPSY There has been growing interest in the association between abnormalities of bone health and epilepsy in recent years. PWE who are housebound or institutionalised, avoid sunlight for cultural reasons, or have poor nutrition are at increased risk of vitamin D deficiency. This can predispose to osteopenia/osteoporosis and proximal myopathy leading to weakness and increased fall liability. Associated conditions such as cerebral palsy with inability to weight bear, reduced physical activity, or visual impairment can be contributory factors. Anti-seizure drug (ASD) side-effects like ataxia, sedation, and seizures, especially convulsive ones, can increase the risk of falls and subsequent fractures particularly in those with reduced bone mineral density (BMD).Attention, however, has focused mainly on ASDs and their role in abnormal bone metabolism. The relationship between abnormalities of bone health and ASDs is commonly thought to be due to the enzyme-inducing properties of many ASDs leading to reduced serum vitamin D levels, but this is not the only mechanism. Sodium valproate, an enzyme inhibitor, is also associated with reduced BMD and increased risk of fractures. Other mechanisms suggested include inhibition of intestinal calcium absorption, osteoclast cell growth, cellular response to parathyroid hormone and calcitonin secretion, and direct effects on bone cells.4 Newer ASDs might have a more positive relationship with bone health than older ones.The National Osteoporosis Society has adopted the definition of vitamin D deficiency used by the National Institute for Health and Care Excellence.5 They recommend that serum vitamin D concentrations for all individuals in the UK should not fall below 25 nmol/L at any time of the year, in order to protect musculoskeletal health. They also recommend treatment for individuals with a serum vitamin D between 25 nmol/L and 50 nmol/L for certain situations. This includes the following: fragility fracture, osteoporosis, high fracture risk, and symptoms suggestive of vitamin D deficiency or increased risk of developing vitamin D deficiency including raised serum parathyroid hormone and treatment with ASDs.

[学科分类] 卫生学