社區老年人睡眠品質與記憶表現的初步探討

The Impact of Sleep Quality on Memory Performance in Community Elderlies: A Preliminary Study

研究目的：台灣老年人口持續攀升，其相關的健康議題是值得重視與探討，老年人比起年輕族群會更頻繁地醒來，再入睡的時間長度相對也增加。睡眠對記憶有固化的作用，早期研究指出，剝奪快速眼動期（REM）的睡眠會對記憶的保留有顯著的傷害，年齡越長則快速眼動期在睡眠中出現的比例越少，因此，有學者提出睡眠對記憶的固化會隨著年齡上升而下降，但是一些研究認為睡眠對記憶的固化沒有影響但能提升再認記憶的能力，因此在老人中，睡眠與記憶的關係尚無一致的結論，本研究針對正常老人，在藥物、疾病控制的條件下，討論正常老人的睡眠品質與記憶能力之間的相關性探討。研究方法：從社區162位年齡65歲以上的老年人，篩選出32位失眠組個案（佔22.37%）及40位正常組，以簡式心智狀態檢查表（MMSE）進行初步認知功能評估，以魏氏成人智力量表之語文理解指標評量其基本認知功能，以匹茲堡睡眠品質指數量表與失眠嚴重度量表評估其睡眠品質，再分別以魏氏成人智力量表中的數字廣度測驗、魏氏記憶量表中文版的邏輯記憶測驗及受試者自傳式記憶測驗作為記憶指標，並於兩週後以相同的記憶測驗評估其遺忘速度或學習效果。研究結果：睡眠正常與失眠組的老年人，反應在短期記憶能力方面的記憶廣度上並無差異；在工作記憶的指標部分，失眠組的平均得分顯著低於正常組；失眠組在兩週後的自傳式記憶減少程度比正常老年組多，代表其遺忘程度高；失眠組在邏輯記憶之增加程度則低於睡眠正常的老年人。討論：本研究支持睡眠品質影響記憶的固化作用，可能是由於睡眠品質差導致對訊息深度處理的能力不足，以致於影響其固化作用，睡眠品質不佳導致兩週後對於先前記憶的提取能力降低。

The elderly population continues to rise in Taiwan, and its associated health issues are worthy of attention and discussion. In terms of sleep, older adults wake up in the middle of the night more often than younger adults, and take more time to fall asleep again. Sleep quality has been associated with memory consolidation. Previous studies have indicated that the deprivation of rapid eye movement (REM) sleep may lead to memory impairment. Since the total time of REM sleep decreases with age, it is reasonable to hypothesize that the sleep quality of elderly adults affects their memory performance. Methods: One-hundred and sixty-two older adults were screened, and 32 cases of insomnia (accounting for 22.37% of the original smaple), and 40 normal controls were retained. The Mini-Mental State Examination (MMSE) was used as a preliminary assessment of cognitive functioning; and the Verbal Comprehension Index of the Wechsler Intelligence Scale was used to assess the participants’ basic cognitive functioning. The Pittsburgh Sleep Quality Index Scale and the Insomnia Severity Scale were used to assess the quality of sleep. The Digit Span subtest of the Wechsler Adult Intelligence Scale, the Wechsler Memory Scale Logical Memory Test, and the Autobiographical Memory Test were used to assess memory. The same tests were administrated again 2 weeks later. Results: There was a significant difference between the insomniac group and the normal group on the working memory indices after 2 weeks. In the insomniac group, memory loss was higher for autobiographical memories, and learning rates on logical memory was lower. Discussion: This study supports that quality of sleep affects memory consolidation in older adults. It may be that poor quality of sleep leads to the impairment of brain’s capacity for deeper processing of information.