MEDICC Rev. 2020 Oct;22(4):40-47. doi: 10.37757/MR2020.V22.N4.14.
INTRODUCTION Age-related cognitive disorders, including Alzheimer disease, are among the main causes of disability and dependence in older adults worldwide. High blood homocysteine levels (hyperhomocysteinemia) are a risk factor for diseases whose metabolism involves different B vitamins. Antioxidant vitamins provide a protective effect by mitigating oxidative stress generated by these diseases. Epidemiological studies have presented varying results on the relationships between blood levels of these vitamins and such cognitive disorders. OBJECTIVE Evaluate the association of vitamin and homocysteine levels with mild cognitive impairment and Alzheimer disease in a group of Cuban older adults. METHODS A cross-sectional study was conducted in Havana, Cuba, of 424 persons aged ≥65 years: 43 with Alzheimer disease, 131 with mild cognitive impairment, and 250 with no signs of cognitive impairment. Dementia was diagnosed using criteria of the International 10/66 Dementia Research Group and Diagnostic and Statistical Manual of Mental Disorders (DSM IV), and mild cognitive impairment was diagnosed using Petersen's criteria. Blood levels of vitamins (thiamine, B-2, folate, B-12, C and A) and homocysteine were measured by standard procedures. Analysis of variance for continuous variables and percentage comparison tests for dichotomous variables were used to compare groups. RESULTS Persons with Alzheimer disease presented signifi cantly lower levels of vitamins B-2, C and A than healthy participants (p <0.05). Homocysteine levels were signifi cantly higher in those with Alzheimer disease and mild cognitive impairment than in participants with no cognitive impairment (p <0.05). Statistically, levels of thiamine, folic acid, and vitamin B-12 were not signifi cantly different across groups. Compared with those without cognitive impairment, prevalence rates (PR) in the Alzheimer group were signifi cantly higher for hyperhomocysteinemia (PR = 3.26; 1.84-5.80) and defi - ciency of all B vitamins: thiamine (PR = 1.89; 1.04-3.43), B-2 (PR = 2.85; 1.54-5.26), folate (PR = 3.02; 1.53-5.95), B-12 (PR = 2.21; 1.17-4.19), vitamin C (PR = 3.88; 2.12-7.10) and A (PR = 5.47; 3.26-9.17). In mild cognitive impairment, prevalence rates were signifi cantly higher for hyperhomocysteinemia (PR = 1.42; 1.08-1.87), vitamin B-2 defi ciency (PR = 1.70; 1.24-2.32) and vitamin A defi - ciency (PR =1.88; 1.05-3.38). CONCLUSIONS Hyperhomocysteinemia and various vitamin defi ciencies are related to Alzheimer disease and mild cognitive impairment. Longitudinal studies are needed to further elucidate the relationship between different nutritional biomarkers and dementia. A better understanding of this relationship could provide a basis for therapeutic and preventive strategies. KEYWORDS Vitamins, homocysteine, geriatrics, Alzheimer disease, cognitive impairment, Cuba.
与年龄相关的认知障碍，包括阿尔茨海默病，是全世界导致老年人残疾和依赖的主要原因之一。血液同型半胱氨酸水平升高（高同型半胱氨酸血症）是涉及不同 B 族维生素代谢的疾病的一个危险因素。抗氧化维生素通过减轻这些疾病产生的氧化应激提供保护作用。流行病学研究对这些维生素的血液水平与这些认知障碍之间的关系呈现出不同的结果。目的：评估维生素和同型半胱氨酸水平与一组古巴老年人轻度认知障碍和阿尔茨海默病之间的关系。方法：在古巴哈瓦那进行了一项横断面研究，共纳入 424 名年龄≥65 岁的人：43 名患有阿尔茨海默病，131 名患有轻度认知障碍，250 名无认知障碍。使用国际 10/66 痴呆症研究组和精神障碍诊断与统计手册（DSM-IV）的标准诊断痴呆症，使用彼得森的标准诊断轻度认知障碍。通过标准程序测量维生素（硫胺素、B-2、叶酸、B-12、C 和 A）和同型半胱氨酸的血液水平。使用方差分析比较连续变量，使用百分比比较检验比较二分类变量。结果：患有阿尔茨海默病的患者血液中的维生素 B-2、C 和 A 水平明显低于健康参与者（p<0.05）。患有阿尔茨海默病和轻度认知障碍的患者的同型半胱氨酸水平明显高于无认知障碍的参与者（p<0.05）。统计学上，各组间的硫胺素、叶酸和维生素 B-12 水平无显著差异。与无认知障碍者相比，阿尔茨海默病组的高同型半胱氨酸血症（患病率比 [PR] = 3.26；1.84-5.80）和所有 B 族维生素缺乏的患病率比 [PR]更高：硫胺素（PR = 1.89；1.04-3.43）、B-2（PR = 2.85；1.54-5.26）、叶酸（PR = 3.02；1.53-5.95）、B-12（PR = 2.21；1.17-4.19）、维生素 C（PR = 3.88；2.12-7.10）和 A（PR = 5.47；3.26-9.17）。在轻度认知障碍中，高同型半胱氨酸血症（PR = 1.42；1.08-1.87）、维生素 B-2 缺乏（PR = 1.70；1.24-2.32）和维生素 A 缺乏（PR = 1.88；1.05-3.38）的患病率比也显著更高。结论：高同型半胱氨酸血症和各种维生素缺乏与阿尔茨海默病和轻度认知障碍有关。需要进行纵向研究以进一步阐明不同营养生物标志物与痴呆症之间的关系。更好地了解这种关系可以为治疗和预防策略提供依据。关键词：维生素、同型半胱氨酸、老年医学、阿尔茨海默病、认知障碍、古巴。
