Cao Jie, Xu Shabei, Liu Chenchen
Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Medicine (Baltimore). 2020 Apr;99(14):e19700. doi: 10.1097/MD.0000000000019700.
To determine the prevalence of subacute combined degeneration (SCD) patients with normal or elevated serum vitamin B12 level and to identify clinical characteristics of these patients.
We searched PubMed, EMBASE, and Cochrane library, without language restriction up to June 2019 and included studies with SCD patients who were diagnosed with normal or elevated serum vitamin B12 levels. Meta-analysis was performed to estimate the prevalence of SCD in patients with normal or elevated serum vitamin B12 levels and compare the differences of clinical data between patients with low and no-low serum vitamin B12 level.
Six studies were included in our analysis, with a total number of 181 patients involved. The pooled proportion in patients with no-low serum vitamin B12 level was 31.0% (95% confidence interval [CI]: 22.5-40.8). There was no significant difference in the level of hemoglobin (Mean difference (MD): -3.05, 95% CI: -12.42 to 6.33. P = 0.52) and erythrocyte mean corpuscular volume (MD: -2.37, 95% CI: -11.17 to 6.43, P = 0.60) between SCD patients with no-low and those with low serum vitamin B12 levels. The meta-analysis showed that the functional disability rating scale on admission in patients with low serum vitamin B12 level was no worse than that with normal or elevated serum vitamin B12 level (MD: 0.29, 95% CI: -0.58 to 1.16, P = 0.51).
Decreased level of serum vitamin B12 may not be a necessity for the diagnosis of SCD. Approximately one third of the SCD patients have normal or elevated serum vitamin B12 level. No differences were found in clinical severity between patients with normal or elevated serum vitamin B12 level and those with low level of serum vitamin B12 on admission.
确定血清维生素B12水平正常或升高的亚急性联合变性（SCD）患者的患病率，并识别这些患者的临床特征。
检索PubMed、EMBASE和Cochrane图书馆，检索截至2019年6月无语言限制的文献，并纳入血清维生素B12水平正常或升高的SCD患者的研究。进行荟萃分析以估计血清维生素B12水平正常或升高的患者中SCD的患病率，并比较血清维生素B12水平低和不低的患者之间临床数据的差异。
我们的分析纳入了6项研究，共涉及181例患者。血清维生素B12水平不低的患者的合并比例为31.0%（95%置信区间[CI]：22.5-40.8）。血清维生素B12水平不低的SCD患者与低水平患者之间的血红蛋白水平（平均差[MD]：-3.05，95%CI：-12.42至6.33，P = 0.52）和红细胞平均体积（MD：-2.37，95%CI：-11.17至6.43，P = 0.60）无显著差异。荟萃分析表明，血清维生素B12水平低的患者入院时的功能残疾评定量表并不比血清维生素B12水平正常或升高的患者差（MD：0.29，95%CI：-0.58至1.16，P = 0.51）。
血清维生素B12水平降低可能不是诊断SCD的必要条件。约三分之一的SCD患者血清维生素B12水平正常或升高。入院时血清维生素B12水平正常或升高的患者与血清维生素B12水平低的患者在临床严重程度上没有差异。
