中文摘要：

目的探讨遗忘型轻度认知障碍（aMCI）与血管紧张素转换酶（ACE）基因插入和缺失（I／D）多态性及血清ACE活力水平的关系。方法对符合美国Meyo诊所Petersen等制定的aMCI诊断标准的90例aMCI患者（aMCI组）及90名与aMCI组相匹配正常对照者（对照组）进行神经认知功能评估，并应用聚合酶链反应检测ACE基因I／D多态性，用紫外分光光度法检测血清ACE活力水平。结果（1）aMCI组的各项神经认知测试成绩均差于对照组（P〈0．01）。（2）aMCI组ACE基因型（X2=11．510）及等位基因频率（X2=6．945）与对照组的差异均有统计学意义（P〈0．01），其中aMCI组DD基因型（23％）及D等位基因频率（57％）高于对照组（分别为16％和43％）。（3）两组DD基因型（n=35）及DI基因型（n=109）者的听觉词语记忆、符号数字转换测试、复杂图形及类别词语流畅性得分低于Ⅱ基因型者（n=36；均P〈0．05—0．01）。（4）aMCI组（F=7．491）和对照组（F=4．970）ACE基因型各亚组间血清ACE活力水平的差异均有统计学意义（P〈0．01），两组ACE活力水平均为DD型组〉DI型组〉Ⅱ型组。（5）aMCI组血清ACE活力与听觉词语记忆测试的延迟回忆得分呈负相关（r=-0．249，P〈0．05）。结论D等位基因可能为aMCI的发病危险因子，其调控的血清ACE高活力水平与aMCI患者情节记忆损害有关。

英文摘要：

Objective To study the relationship among amnestic mild cognitive impairment （aMCI） and the angiotensin-converting enzyme （ACE） gene polymorphism of intron 16 insertion/deletion （I/D） and serum ACE level. Methods One hundred and eighty subjects （60 - 85 years） were divided into aMCI group （ n = 90） and normal control group （ n = 90） through a series of neuropsychological evaluating. The intrun 16 I/D polymorphism of ACE gene was analyzed by means of polymerase chain reaction （PCR）. The serum ACE levels were measured by using ultraviolet spectrophotometry. Results The scores of neuropsychological tests in aMCI patients were significantly poorer than that in controls （ all P 〈 0.01 ）. The frequencies of DD genotype and D allele of ACE gene were significantly different between aMC! patients and controls （ all P 〈 0.01 ）. The frequencies of DD genotype and D allele were higher in aMCI patients than controls （23% vs. 16% ; 57% vs. 43% ）. ACE genotype was correlated with delayed recall in Auditory Verbal Memory Test （AVMT） , delay recall in Complex Figure Test, Category Fluency Test and Symbol Digit Modalities Test （ all P 〈 0.05 ）, in which DD and DI genotype was lower than II genotype （ P 〈 0.05 ）. A significant difference in serum ACE level was observed among the three genotypes in both aMCI and control group （DD 〉 DI 〉 Ⅱ; P 〈 0.01 ）. AVMT-delay recall had significant correlations with serum ACE level in aMCI group （r = - 0. 249, P 〈 0.05）. Conclusions The ACE gene I/D polymorphism may be correlated with aMCI, with D allele possibly being a genetic risk factor for the development of aMCI. The higher serum ACE level may possibly play a role in the episodic memory impairment of aMCI.