Clarke Robert, Harrison Georgina, Richards Sue
J Intern Med. 2003 Jul;254(1):67-75. doi: 10.1046/j.1365-2796.2003.01154.x.
To examine the association of cognitive impairment with platelet activation and reactive oxygen species and total homocysteine levels; and to assess the biochemical efficacy of treatment with aspirin and vitamin supplements in people at high risk of dementia.
People with dementia or mild cognitive impairment.
In a 2 x 2 x 2 factorial design trial, 149 people at high-risk of dementia were randomized to receive either low-dose aspirin (81 mg) or placebo; and folic acid (2 mg) plus vitamin B12 (1 mg) or placebo; and vitamins E (500 mg) plus C (200 mg) or placebo. Participants were seen twice before and once after 12 weeks of treatment.
At each visit, participants had their cognitive function assessed and had blood collected for homocysteine, folate and vitamin B12 determination and urine collected for markers of platelet activation (11-dehydro-thromboxane B2) and reactive oxygen species (8-epi-PGF2 alpha).
Prior to treatment, cognitive function was inversely related with homocysteine and with urinary thromboxane and isoprostane, and these associations were independent of age. Aspirin was associated with a median reduction in 11-dehydrothromboxane B2 of 73% (P < 0.001). B-vitamins lowered plasma homocysteine concentration by 30% (P < 0.0001) and antioxidant vitamins lowered isoprostane excretion by 26% (P < 0.1). No effect of treatment on cognitive function was detected.
Aspirin and B-vitamins were effective in reducing biochemical factors associated with cognitive impairment in people at risk of dementia. Large-scale trials are now required to assess the relevance of aspirin and B-vitamins for the maintenance of cognitive function in people at risk of dementia.
研究认知障碍与血小板活化、活性氧及总同型半胱氨酸水平之间的关联；并评估阿司匹林和维生素补充剂对痴呆高危人群的生化治疗效果。
患有痴呆或轻度认知障碍的人群。
在一项2×2×2析因设计试验中，149名痴呆高危人群被随机分为接受低剂量阿司匹林（81毫克）或安慰剂；叶酸（2毫克）加维生素B12（1毫克）或安慰剂；维生素E（500毫克）加维生素C（200毫克）或安慰剂。参与者在治疗前接受两次检查，治疗12周后接受一次检查。
每次就诊时，评估参与者的认知功能，并采集血液测定同型半胱氨酸、叶酸和维生素B12，采集尿液测定血小板活化标志物（11-脱氢血栓烷B2）和活性氧（8-表前列腺素F2α）。
治疗前，认知功能与同型半胱氨酸、尿血栓烷和异前列腺素呈负相关，且这些关联与年龄无关。阿司匹林使11-脱氢血栓烷B2的中位数降低了73%（P<0.001）。B族维生素使血浆同型半胱氨酸浓度降低了30%（P<0.0001），抗氧化维生素使异前列腺素排泄降低了26%（P<0.1）。未检测到治疗对认知功能的影响。
阿司匹林和B族维生素可有效降低痴呆高危人群中与认知障碍相关的生化因素。现在需要进行大规模试验来评估阿司匹林和B族维生素对痴呆高危人群维持认知功能的相关性。
