银杏叶提取物预防老年人认知能力下降：一项随机试验。
Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial.
机构信息
Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
出版信息
JAMA. 2009 Dec 23;302(24):2663-70. doi: 10.1001/jama.2009.1913.
CONTEXT
The herbal product Ginkgo biloba is taken frequently with the intention of improving cognitive health in aging. However, evidence from adequately powered clinical trials is lacking regarding its effect on long-term cognitive functioning.
OBJECTIVE
To determine whether G. biloba slows the rates of global or domain-specific cognitive decline in older adults.
DESIGN, SETTING, AND PARTICIPANTS: The Ginkgo Evaluation of Memory (GEM) study, a randomized, double-blind, placebo-controlled clinical trial of 3069 community-dwelling participants aged 72 to 96 years, conducted in 6 academic medical centers in the United States between 2000 and 2008, with a median follow-up of 6.1 years.
INTERVENTION
Twice-daily dose of 120-mg extract of G. biloba (n = 1545) or identical-appearing placebo (n = 1524).
MAIN OUTCOME MEASURES
Rates of change over time in the Modified Mini-Mental State Examination (3MSE), in the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS-Cog), and in neuropsychological domains of memory, attention, visual-spatial construction, language, and executive functions, based on sums of z scores of individual tests.
RESULTS
Annual rates of decline in z scores did not differ between G. biloba and placebo groups in any domains, including memory (0.043; 95% confidence interval [CI], 0.034-0.051 vs 0.041; 95% CI, 0.032-0.050), attention (0.043; 95% CI, 0.037-0.050 vs 0.048; 95% CI, 0.041-0.054), visuospatial abilities (0.107; 95% CI, 0.097-0.117 vs 0.118; 95% CI, 0.108-0.128), language (0.045; 95% CI, 0.037-0.054 vs 0.041; 95% CI, 0.033-0.048), and executive functions (0.092; 95% CI, 0.086-0.099 vs 0.089; 95% CI, 0.082-0.096). For the 3MSE and ADAS-Cog, rates of change varied by baseline cognitive status (mild cognitive impairment), but there were no differences in rates of change between treatment groups (for 3MSE, P = .71; for ADAS-Cog, P = .97). There was no significant effect modification of treatment on rate of decline by age, sex, race, education, APOE*E4 allele, or baseline mild cognitive impairment (P > .05).
CONCLUSION
Compared with placebo, the use of G. biloba, 120 mg twice daily, did not result in less cognitive decline in older adults with normal cognition or with mild cognitive impairment.
TRIAL REGISTRATION
clinicaltrials.gov Identifier: NCT00010803.
背景
银杏叶制剂常被用于改善衰老过程中的认知健康，以期提高认知能力。然而，目前缺乏足够有力的临床试验证据来证明其对长期认知功能的影响。
目的
确定银杏叶是否能减缓老年人群的整体或特定领域认知能力下降速度。
设计、地点和参与者：银杏叶评估记忆（GEM）研究是一项在美国 6 家学术医疗中心开展的、随机、双盲、安慰剂对照的临床试验，共有 3069 名年龄在 72 至 96 岁之间的社区居住者参与，于 2000 年至 2008 年间进行，中位随访时间为 6.1 年。
干预
每日 2 次给予 120 毫克银杏叶提取物（n=1545）或外观相同的安慰剂（n=1524）。
主要观察指标
基于个体测试的 z 分数总和，使用改良的简易精神状态检查（3MSE）、阿尔茨海默病评估量表认知子量表（ADAS-Cog）以及记忆、注意力、视觉空间构建、语言和执行功能等神经心理学领域的变化率。
结果
在任何领域，包括记忆（0.043；95%置信区间，0.034-0.051 与 0.041；95%置信区间，0.032-0.050）、注意力（0.043；95%置信区间，0.037-0.050 与 0.048；95%置信区间，0.041-0.054）、视空间能力（0.107；95%置信区间，0.097-0.117 与 0.118；95%置信区间，0.108-0.128）、语言（0.045；95%置信区间，0.037-0.054 与 0.041；95%置信区间，0.033-0.048）和执行功能（0.092；95%置信区间，0.086-0.099 与 0.089；95%置信区间，0.082-0.096），银杏叶组和安慰剂组的 z 分数年变化率均无差异。对于 3MSE 和 ADAS-Cog，变化率因基线认知状态（轻度认知障碍）而异，但治疗组之间的变化率没有差异（对于 3MSE，P=0.71；对于 ADAS-Cog，P=0.97）。年龄、性别、种族、教育程度、APOE*E4 等位基因或基线轻度认知障碍等因素对治疗与下降率之间的交互作用无显著影响（P>0.05）。
结论
与安慰剂相比，每日服用 120 毫克银杏叶，并未使认知正常或轻度认知障碍的老年患者的认知能力下降速度减缓。
试验注册
clinicaltrials.gov 标识符：NCT00010803。
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