Department of Anatomy, Hebei Medical University, Shijiazhuang, China.
Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China.
J Alzheimers Dis. 2023;94(s1):S267-S287. doi: 10.3233/JAD-221076.
There is increasing evidence that supplementation of S-adenosylmethionine (SAM) can improve cognitive function in animals and humans, although the outcomes are not always inconsistent.
We conducted a systematic review and meta-analysis to evaluate the correlation between SAM supplementation and improved cognitive function.
We searched studies in the PubMed, Cochrane Library, Embase, Web of Science, and Clinical Trials databases from January 1, 2002 to January 1, 2022. Risk of bias was assessed using the Cochrane risk of bias 2.0 (human studies) and the Systematic Review Center for Laboratory Animal Experimentation risk of bias (animal studies) tools; and evidence quality was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation. STATA software was employed to perform meta-analysis, and the random-effects models was used to evaluate the standardized mean difference with 95% confidence intervals.
Out of the 2,375 studies screened, 30 studies met the inclusion criteria. Meta-analyses of animal (p = 0.213) and human (p = 0.047) studies showed that there were no significant differences between the SAM supplementation and control groups. The results of the subgroup analyses showed that the animals aged ≤8 weeks (p = 0.027) and the intervention duration >8 weeks (p = 0.009) were significantly different compared to the controls. Additionally, the Morris water maze test (p = 0.005) used to assess the cognitive level of the animals revealed that SAM could enhance spatial learning and memory in animals.
SAM supplementation showed no significant improvement in cognition. Therefore, further studies are needed to assess the effectiveness of SAM supplementation.
越来越多的证据表明，补充 S-腺苷甲硫氨酸（SAM）可以改善动物和人类的认知功能，但结果并不总是一致的。
我们进行了一项系统评价和荟萃分析，以评估 SAM 补充与认知功能改善之间的相关性。
我们检索了 2002 年 1 月 1 日至 2022 年 1 月 1 日期间 PubMed、Cochrane 图书馆、Embase、Web of Science 和临床试验数据库中的研究。使用 Cochrane 偏倚风险 2.0（人类研究）和系统评价中心实验室动物实验偏倚风险（动物研究）工具评估偏倚风险；使用推荐评估、制定和评估分级评估证据质量。使用 STATA 软件进行荟萃分析，使用随机效应模型评估标准化均数差值及其 95%置信区间。
在筛选出的 2375 项研究中，有 30 项符合纳入标准。对动物（p=0.213）和人类（p=0.047）研究的荟萃分析显示，SAM 补充组与对照组之间没有显著差异。亚组分析结果表明，≤8 周龄的动物（p=0.027）和干预持续时间>8 周的动物（p=0.009）与对照组相比差异有统计学意义。此外，用于评估动物认知水平的 Morris 水迷宫测试（p=0.005）表明，SAM 可以增强动物的空间学习和记忆能力。
SAM 补充对认知功能没有显著改善。因此，需要进一步研究来评估 SAM 补充的有效性。
