Nilsson K, Gustafson L, Hultberg B
Department of Psychogeriatrics, Division of Clinical Chemistry, University of Lund, University Hospital, S-22185 Lund, Sweden.
Clin Chem. 2000 May;46(5):691-6.
Cobalamin/folate deficiency in elderly subjects may lead to psychiatric symptoms, but more often it increases the severity of various organic and nonorganic mental diseases. A major clinical problem, however, is the uncertainty and controversy concerning biochemical markers of cobalamin/folate deficiency to be used in the diagnostic evaluation of suspected cobalamin/folate deficiency.
We measured plasma homocysteine (tHcy), blood folate, serum methylmalonic acid, and serum cobalamin in 80 psychogeriatric patients (age, 77.3 +/- 8.6 years) and 50 controls (age, 76.1 +/- 8. 0 years). We assessed associations of these tests with measures of cognitive and behavior performance by use of regression analyses.
Plasma tHcy was increased in 45% of the psychogeriatric population (mean, 20.5 +/- 9.2 micromol/L vs 15.3 +/- 4.7 micromol/L for controls; P <0.01). Plasma tHcy correlated with severity of dementia (r = 0.36; P <0.01), the Katz ADL index (r = 0.29; P <0.05), the Berger scale (r = 0.29; P <0.05), and the score of symptoms (r = 0.39; P <0.001) in the psychogeriatric population. Similarly, blood folate was significantly correlated with these measures, but the concentrations of serum cobalamin and methylmalonic acid were not. In a stepwise multiple regression analysis including the biochemical markers, tHcy was the only significant predictor of the severity of dementia (r(2) = 0.11; P <0.01) and the score of symptoms (r(2) = 0.16; P <0.001).
Plasma tHcy is the best marker of those measured to investigate suspected tissue deficiency of cobalamin/folate.
老年受试者体内钴胺素/叶酸缺乏可能导致精神症状，但更常见的是它会加重各种器质性和非器质性精神疾病的严重程度。然而，一个主要的临床问题是，在疑似钴胺素/叶酸缺乏的诊断评估中，用于检测钴胺素/叶酸缺乏的生化标志物存在不确定性和争议。
我们测量了80名老年精神病患者（年龄77.3±8.6岁）和50名对照者（年龄76.1±8.0岁）的血浆同型半胱氨酸（tHcy）、血叶酸、血清甲基丙二酸和血清钴胺素。我们通过回归分析评估了这些检测指标与认知和行为表现测量值之间的关联。
45%的老年精神病患者血浆tHcy升高（平均值为20.5±9.2微摩尔/升，而对照组为15.3±4.7微摩尔/升；P<0.01）。在老年精神病患者群体中，血浆tHcy与痴呆严重程度（r = 0.36；P<0.01）、Katz日常生活活动指数（r = 0.29；P<0.05）、伯杰量表（r = 0.29；P<0.05）以及症状评分（r = 0.39；P<0.001）相关。同样，血叶酸与这些测量值显著相关，但血清钴胺素和甲基丙二酸的浓度则不然。在一项包括生化标志物的逐步多元回归分析中，tHcy是痴呆严重程度（r² = 0.11；P<0.01）和症状评分（r² = 0.16；P<0.001）的唯一显著预测因子。
在检测疑似钴胺素/叶酸组织缺乏的指标中，血浆tHcy是最佳标志物。
