Loikas Saila, Koskinen Pertti, Irjala Kerttu, Löppönen Minna, Isoaho Raimo, Kivelä Sirkka-Liisa, Pelliniemi Tarja-Terttu
Department of Clinical Chemistry, University of Turku, Turku, Finland.
Age Ageing. 2007 Mar;36(2):177-83. doi: 10.1093/ageing/afl150. Epub 2006 Dec 21.
vitamin B12 deficiency is common in the aged, but it is controversial whether only some risk groups should be investigated instead of screening the entire aged population.
to describe the prevalence of vitamin B12 deficiency in the Finnish aged, and to find out if the subjects especially prone to vitamin B12 deficiency could be identified by the risk factors or clinical correlates.
a cross-sectional, population-based study of 1048 aged subjects (age 65-100 years) was carried out. Data on lifestyle factors and clinical conditions were collected, physical examinations were conducted and laboratory variables related to vitamin B12 were measured.
vitamin B12 deficiency had been previously diagnosed in 27 (2.6%) subjects, and a laboratory diagnosis (total vitamin B12 <150 pmol/l, or total vitamin B12 150-250 pmol/l and holotranscobalamin < or =37 pmol/l and homocysteine > or =15 micromol/l) was made for 97 (9.5%) subjects. Low serum total vitamin B12 (<150 pmol/l) was observed in 6.1% and borderline total vitamin B12 (150-250 pmol/l) in 32% of the subjects. Male gender (OR 1.9, 95% CI 1.2-2.9), age > or =75 (OR 2.2, 95% CI 1.4-3.4) and refraining from milk products (OR 2.3, 95% CI 1.2-4.4) increased the probability for vitamin B12 deficiency. Anaemia (OR 1.3, 95% CI 0.7-2.3) or macrocytosis (OR 1.2, 95% CI 0.6-2.7) did not predict vitamin B12 deficiency.
undiagnosed vitamin B12 deficiency is remarkably common in the aged, but no specific risk group for screening can be identified. Thus, biochemical screening of unselected aged population is justified. General practitioners play a key role in diagnosing early vitamin B12 deficiency.
维生素B12缺乏在老年人中很常见，但对于是否仅应对某些风险群体进行调查而非对全体老年人群进行筛查存在争议。
描述芬兰老年人中维生素B12缺乏的患病率，并确定是否可以通过风险因素或临床关联因素识别出特别容易患维生素B12缺乏的受试者。
对1048名年龄在65至100岁之间的老年受试者进行了一项基于人群的横断面研究。收集了生活方式因素和临床状况的数据，进行了体格检查并测量了与维生素B12相关的实验室变量。
先前已诊断出27名（2.6%）受试者存在维生素B12缺乏，97名（9.5%）受试者通过实验室诊断（总维生素B12<150 pmol/L，或总维生素B12为150 - 250 pmol/L且全转钴胺素≤37 pmol/L且同型半胱氨酸≥15 μmol/L）确诊。6.1%的受试者血清总维生素B12水平低（<150 pmol/L），32%的受试者血清总维生素B12处于临界水平（150 - 250 pmol/L）。男性（比值比1.9，95%置信区间1.2 - 2.9）、年龄≥75岁（比值比2.2，95%置信区间1.4 - 3.4）以及不食用奶制品（比值比2.3，95%置信区间1.2 - 4.4）会增加维生素B12缺乏的可能性。贫血（比值比1.3，95%置信区间0.7 - 2.3）或大细胞性贫血（比值比1.2，95%置信区间0.6 - 2.7）并不能预测维生素B12缺乏。
未诊断出的维生素B12缺乏在老年人中非常普遍，但无法确定特定的筛查风险群体。因此，对未经过挑选的老年人群进行生化筛查是合理的。全科医生在早期诊断维生素B12缺乏方面起着关键作用。
