生酮飲食在先天性代謝異常的治療角色

生酮飲食是一種高脂肪、中等蛋白質和最少碳水化合物的飲食方案，它模仿禁食狀態在體內產生酮體。多年來，生酮飲食已被報導為治療頑固性癲癇的成功飲食療法。此外，通過對其作用機制的最新瞭解，已經報導出它對某些先天性或遺傳性代謝疾病(inherited metabolic disease, IMD)的治療潛力。首先，生酮飲食是葡萄糖轉運蛋白第1型缺乏綜合症候群(glucose transporter type 1 deficiency syndrome, GLUT1-DS)和丙酮酸脫氫酶複合物(pyruvate dehydrogenase complex, PDHC)缺乏症的首選療法，因為它直接改善這兩種疾病的潛在代謝需求。在其他IMDs中，主要是中間代謝，如糖原貯積病和粒線體疾病之能量供應，生酮飲食可以改善其臨床症狀和實驗室異常。最後，生酮飲食可有效治療IMD所引起之癲癇發作，例如尿素循環障礙和非酮症性高甘氨酸血症等之種種臨床抽搐問題。實用性建議：使用生酮飲食治療先天性代謝疾病的過程中，應定期追蹤病人臨床變化、實驗室數據及相關檢查，以確保治療效果，有個別化的設計及記錄尤佳。

Ketogenic diet (KD) is a high fat, moderate protein, and minimal carbohydrate diet regimen that mimics the fasting state to produce ketone bodies in the body. Ketogenic diet therapy (KDT) has been reported as a successful dietary therapy for the treatment of intractable epilepsy for many years. Besides, its therapeutic potential for some congenital or inherited metabolic diseases (IMDs) has been proposed through recent advances of understanding of its action mechanisms. KDT is the therapy of choice for glucose transporter type 1 deficiency syndrome (Glut1-DS) and pyruvate dehydrogenase complex (PDHc) deficiency as it directly targets the underlying metabolic needs of these two diseases. In other IMDs, mainly of intermediary metabolism such as glycogen storage diseases and disorders of mitochondrial energy supply, KDs may ameliorate clinical symptoms and laboratory abnormalities. KDs have been effective to treat symptoms such as seizures in IMD, e.g. in urea cycle disorders and non-ketotic hyperglycinemia. A practical recommendation for patients with IMD treated with KDs is to have closed individualized records of clinical features, laboratory data, and related testing to ensure the therapeutic effect.