Effect of the treatment of Type II diabetes mellitus on the development of cognitive impairment and dementia

  • Review
  • Intervention

Authors


Abstract

Background

There is increasing interest in preventing cognitive impairment and dementia in later life. Epidemiological evidence shows a relationship between cognitive impairment and Type II diabetes. This association is stronger in patients who have been diagnosed for longer periods of time and in those who are on insulin therapy. There is little information on the short- and long-term influence of type of treatment and level of metabolic control on cognitive function of people with diabetes.

Objectives

To assess the effects of different types and intensities of treatments for Type II diabetes on cognitive function.

Search methods

The CENTRAL Register of Controlled Trials, MEDLINE, EMBASE, PsycINFO, SIGLE LILACS and CINAHL as well as a number of ongoing trials databases were last searched on 4 August 2005 using appropriate strategies.

Selection criteria

Randomized controlled trials in which different treatments for Type II diabetes have been compared and in which measures of cognitive function were made at entry and after the treatment.

Data collection and analysis

Two reviewers independently assessed trial quality. Five trials were identified for possible inclusion but none of them could be included. In one, cognitive function was assessed before and after intensive or conventional diabetic treatment, but the comparison was not double-blind. The three other studies explored the effect of different treatments on QOL but did not include appropriate evaluation of cognitive function. The fifth did not report baseline data on cognitive function in the trial groups.

Main results

No studies were found to be appropriate for inclusion in meta-analysis.

Authors' conclusions

There is no convincing evidence relating type or intensity of diabetic treatment to the prevention or management of cognitive impairment in Type II diabetes. Future research on treatments for diabetes should include standardized assessments of cognitive function as outcome measures.

摘要

背景

治療第二型糖尿病對認知功能障礙和失智症發展上的影響

預防老年人的認知功能障礙和失智症已漸漸受到重視。流行病學的證據顯示認知功能障礙與第二型糖尿病之間是有關連性的。這關係尤其與長期患有糖尿病和使用胰島素治療有關。目前很少資訊提及治療類型和新陳代謝控制程度,對於糖尿病病患認知功能的長期或短期的影響。

目標

評估第二型糖尿病病患使用不同型態和強度的治療對於認知功能的影響

搜尋策略

在2005年8月4日以適當的策略搜尋CENTRAL Register of Controlled Trials、MEDLINE、EMBASE、 PsycINFO, SIGLE LILACS和CINAHL資料庫以及一些正在進行中試驗的資料庫。

選擇標準

收錄隨機性對照試驗有關於比較不同方法來治療第二型糖尿病和病患進入試驗以及治療後的認知功能。

資料收集與分析

2位審查者各自評估試驗品質。5個試驗被發現與主題有關但但最後卻沒有一個納入。其中1個試驗是評估嚴格控制血糖前後、或是使用傳統的糖尿病治療病患的認知功能,但這並不是雙盲性性試驗。其他3個試驗探討不同的療法的對生活品質的影響卻沒有適當的認知功能評估。第5個試驗沒有起始認的知功能報告。

主要結論

並沒有發現適當的試驗可以納入本研究中進行統合分析。

作者結論

缺乏說服性的證據說明糖尿病治療的類型或強度與預防或處理第二型糖尿病的認知功能障礙之間的關係。未來有關糖尿病治療的研究應該包括認知功能並以此作為治療效果的評估。

翻譯人

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

沒有治療或控制第二型糖尿病會影響認知功能的證據。第二型糖尿病是一種慢性疾病,他的特徵就是有高血糖。必須使用飲食,口服藥物以及有時以胰島素來控制症狀和避免器官損壞。病人或許會比健康人更早出現認知功能衰退(如記憶問題)。本研究試圖去釐清治療類型或控制血糖對認知功能的影響。沒有任何一個試驗有足夠高質量的數據去証明任何的結論。將來在第二型糖尿病治療的試驗在評估治療結果上應該包含認知功能的測量。

Plain language summary

No evidence that treatment or level of control of Type II diabetes influences cognitive function

Type II diabetes is a chronic disease characterized by high blood glucose levels. It needs to be treated with diet, oral drugs and sometimes insulin to control symptoms and avoid organ damage. Patients may develop features of cognitive decline (e.g. memory problems) earlier than healthy people. This review tries to clarify whether the type of treatment or control of the glycemia influences cognitive function. None of the studies identified had sufficient high quality data to justify any conclusion. Future trials of treatment for Type II diabetes should include measures of cognitive function as an outcome.

Laienverständliche Zusammenfassung

Keine Evidenz dafür, dass die Behandlung oder der Einstellen des Diabetes Typ 2 die kognitive Leistung beeinflusst

Typ 2 Diabetes ist eine chronische Erkrankung, bei der die Blutzuckerwerte erhöht sind. Zur Vermeidung von Beschwerden und Organschäden wird Diabetes durch Diät, mit Medikamenten und manchmal Insulin behandelt. Diabetiker können früher als Gesunde Zeichen eines kognitiven Zerfalls, z.B. mit Gedächtnisstörungen, haben. Diese Übersichtsarbeit untersucht, ob die Art der Behandlung oder der Einstellung einen Einfluss auf die kognitiven Fähigkeiten hat. Es wurden keine qualitativ hochwertigen Studien gefunden, aus denen man hätte Schlüsse ziehen können. Zukünftige Studien zur Behandlung des Typ 2 Diabetes sollten auch die Messung der kognitive Funktion als Endpunkt beinhalten.

Anmerkungen zur Übersetzung

Koordination durch Cochrane Schweiz