Doncheva Nadezhda, Penkov Alexandar, Velcheva Anita, Boev Micho, Popov Bojidar, Niagolov Yuri
Department of Clinical Lipidology, Medical Institute, Ministry of Interior, Sofia, Bulgaria.
Ann Nutr Metab. 2007;51(1):82-7. doi: 10.1159/000100825. Epub 2007 Mar 15.
Elevated total homocysteine (tHCY) is a known risk factor for atherosclerotic vascular disease, but the mechanism is not well understood. The study was designed to estimate tHCY concentration and other risk factors in coronary heart disease (CHD) males, evaluating two different methods for tHCY measurement: gas chromatography-mass spectrometry (GC-MS) method and competitive immunoassay method.
Fifty men, mean age 53.9 years with CHD and a body mass index (BMI) >25.0, were examined for tHCY concentrations, lipids, blood glucose, uric acid, complete blood picture and erythrocyte sedimentation rate and high-sensitive C-reactive protein (hsCRP). Biochemical and hematological indices were determined by routine methods, hsCRP--by immunometric chemiluminescence method, and tHCY--by two different methods: a gas chromatographic method, using GC-MS and a competitive immunoassay method on an Immulite device.
The mean values of the lipids showed moderate dyslipidemia while the other parameters were within reference range. Mean BMI was 28.5 +/- 0.42. Values of tHCY determined by the immunoassay method were 13.2 +/- 0.95 micromol/l, and determined by GC-MS - 14.6 +/- 1.09 micromol/l. We found a linear agreement between the DPC and GC-MS sets of measurements (r = 0.87, p < or = 0.001). The median tHCY concentrations measured by immunoassay were lower than those measured with GC-MS, but differences were insignificant. An agreement between the competitive immunoassay and the GC-MS method evaluated by the Bland and Altman method was found. tHCY was >15 micromol/l in 12 patients as determined by the competitive immunoassay, and in 15 patients by the GC-MS method. tHCY levels were between 10 and 15 micromol/l in 24 patients by the immunoassay and in 29 patients by the GC-MS method. Twenty-four percent of the patients with CHD have an 'increased risk' with tHCY >15 micromol/l, and 48% are in the 'gray zone' with tHCY levels between 10 and 15 micromol/l.
40.8% of the studied patients had increased tHCY levels, not associated with the other lipid and nonlipid risk factors. The closest conformity between GC-MS and immunoassay methods was observed for serum tHCY concentrations. The between-method comparison reveals that the above-mentioned methods can be used interchangeably.
总同型半胱氨酸（tHCY）升高是动脉粥样硬化性血管疾病的已知危险因素，但其机制尚不完全清楚。本研究旨在评估冠心病（CHD）男性患者的tHCY浓度及其他危险因素，同时评估两种不同的tHCY测量方法：气相色谱-质谱联用（GC-MS）法和竞争性免疫分析法。
选取50名年龄平均为53.9岁、患有冠心病且体重指数（BMI）>25.0的男性，检测其tHCY浓度、血脂、血糖、尿酸、全血细胞计数、红细胞沉降率及高敏C反应蛋白（hsCRP）。生化和血液学指标采用常规方法测定，hsCRP采用免疫化学发光法测定，tHCY采用两种不同方法测定：一种是使用GC-MS的气相色谱法，另一种是在Immulite设备上进行的竞争性免疫分析法。
血脂平均值显示为中度血脂异常，而其他参数均在参考范围内。平均BMI为28.5±0.42。免疫分析法测定的tHCY值为13.2±0.95微摩尔/升，GC-MS法测定的值为14.6±1.09微摩尔/升。我们发现DPC和GC-MS测量结果之间呈线性一致（r = 0.87，p≤0.001）。免疫分析法测定的tHCY中位数浓度低于GC-MS法测定的浓度，但差异不显著。通过Bland和Altman方法评估发现竞争性免疫分析法与GC-MS法之间具有一致性。竞争性免疫分析法测定12例患者的tHCY>15微摩尔/升，GC-MS法测定15例患者的tHCY>15微摩尔/升。免疫分析法测定24例患者的tHCY水平在10至15微摩尔/升之间，GC-MS法测定29例患者的tHCY水平在10至15微摩尔/升之间。24%的冠心病患者tHCY>15微摩尔/升，处于“风险增加”状态，48%的患者tHCY水平在10至15微摩尔/升之间，处于“灰色区域”。
40.8%的研究患者tHCY水平升高，且与其他脂质和非脂质危险因素无关。血清tHCY浓度方面，GC-MS法与免疫分析法最为接近。方法间比较表明上述方法可互换使用。
