Department of Biochemistry and Molecular Biology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh.
Department of Neurology, Headache Centre, San Lazzaro Hospital, Alba, Italy.
CNS Neurol Disord Drug Targets. 2021;20(8):736-754. doi: 10.2174/1871527320666210804155617.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by sleep, behavioral, memory, and cognitive deteriorations. Sleep disturbance (SD) is a major disease burden in AD, which has a reciprocal relationship with AD pathophysiology. It aggravates memory, behavioral, and cognitive complications in AD. Different studies have found that melatonin hormone levels reduce even in the pre-clinical stages of AD. Melatonin is the primary sleep-regulating hormone and a potent antioxidant with neuroprotective roles. The decrease in melatonin levels can thus promote SD and AD neuropathology. Exogenous melatonin has the potential to alleviate neuropathology and SD in AD by different mechanisms. Various studies have been conducted to assess the efficacy of exogenous melatonin to treat SD in AD. Though most of the studies suggest that melatonin is useful to ameliorate SD in AD, the remaining studies show opposite results. The timing, dosage, and duration of melatonin administration along with disease condition, genetic, environmental, and some other factors can be responsible for the discrepancies between the studies. More extensive trials with longer durations and higher dosage forms and studies including bright light therapy and melatonin agonists (ramelteon, agomelatine, and tasimelteon) should be performed to determine the efficacy of melatonin to treat SD in AD.
阿尔茨海默病（AD）是一种进行性神经退行性疾病，其特征是睡眠、行为、记忆和认知能力下降。睡眠障碍（SD）是 AD 的主要疾病负担，与 AD 病理生理学呈双向关系。它会加重 AD 中的记忆、行为和认知并发症。不同的研究发现，即使在 AD 的临床前阶段，褪黑素激素水平也会降低。褪黑素是主要的睡眠调节激素，具有神经保护作用的强大抗氧化剂。褪黑素水平的降低因此会促进 SD 和 AD 神经病理学。外源性褪黑素通过不同的机制有可能减轻 AD 的神经病理学和 SD。已经进行了各种研究来评估外源性褪黑素治疗 AD 中 SD 的功效。尽管大多数研究表明褪黑素有助于改善 AD 中的 SD，但其余研究结果则相反。褪黑素给药的时间、剂量和持续时间以及疾病状况、遗传、环境和其他一些因素可能是导致这些研究结果不一致的原因。应该进行更广泛的试验，持续时间更长、剂量更高，并包括亮光疗法和褪黑素激动剂（雷美尔酮、阿戈美拉汀和他司美琼），以确定褪黑素治疗 AD 中 SD 的功效。
