Fondazione G.Monasterio CNR-Regione Toscana, Pisa, Italy.
Clin Biochem. 2012 Dec;45(18):1652-7. doi: 10.1016/j.clinbiochem.2012.08.003. Epub 2012 Aug 11.
Vitamin D (25-OHD) physiological functions have been expanded beyond traditional bone health, increasing the importance of its estimation in Laboratory Medicine, which renders validation of available methods mandatory.
We evaluated some preanalytical and analytical aspects of 25-OHD determination and the effects of potentially confounding clinical variables by using the DiaSorin "LIAISON 25-OH Vitamin D TOTAL".
25-OHD samples were extremely stable, at least in the short term, without requiring special transport or storage. Precision intervals (CV%) were: within run (7-11%) and total precision (8-11.5%). Mean (SD) recovery was 96 (2)%. The assay was linear on dilution. Comparison with radioimmunoassay (RIA) yielded acceptable correlation (Inter-rater agreement/kappa coefficient=0.94) and clinical equivalence in the interval from 6 to 55 ng/mL. The assay was evaluated on a general population (N=476, age: 60±14 years, 65 males). The status of 25-OHD resulted inversely related to parathyroid hormone levels (r=-0.21, p<0.001), and aging (r=-0.17, p<0.001), but not to sex. Levels of 25-OHD were found to be sufficient (≥30 ng/mL) only in 54 samples (12%). Marked seasonal 25-OHD variations were observed in 13 subjects (p<0.05). Moreover, a marked seasonal fluctuation was seen in samples collected during the period of February 2010-October 2011 (p≤0.01). Lower 25-OHD concentration was observed in subjects with diabetes (19±9 vs 14±7 ng/mL, p<0.01) and hypertension (20±9 vs 17±9 ng/mL, p<0.01). Moreover, 25-OHD inversely correlated with BMI (r=-0.25, p<0.001). Conversely, no difference in 25-OHD levels was observed between subjects due to smoking habits and dyslipidemia. In multiple logistic regression models, aging is the only significant independent risk factor for low 25-OHD levels (Odds ratio, 95% confidence intervals: 3.1, 1.3-7.3; p≤0.01).
Results confirm the LIAISON 25-OHD assay as a useful tool for 25-OHD estimation in the clinical practice. Lack of vitamin D is common among Italian adults, and appears associated with several cardiovascular risk factors.
维生素 D（25-OHD）的生理功能已经超出了传统的骨骼健康范畴，这使得其在医学实验室中的评估变得更加重要，因此需要对现有的方法进行验证。
我们使用 DiaSorin“LIAISON 25-OH 维生素 D 总”评估了 25-OHD 测定的一些分析前和分析方面，以及潜在的混杂临床变量的影响。
25-OHD 样本在短期内非常稳定，无需特殊运输或储存。精密度（%CV）的范围是：批内（7-11%）和总精密度（8-11.5%）。平均（SD）回收率为 96（2）%。该测定方法在稀释时具有线性关系。与放射免疫测定法（RIA）相比，在 6 至 55ng/mL 范围内具有可接受的相关性（组内一致性/kappa 系数=0.94）和临床等效性。该测定方法在 476 名一般人群（年龄：60±14 岁，65 名男性）中进行了评估。25-OHD 状态与甲状旁腺激素水平呈负相关（r=-0.21，p<0.001），与年龄呈负相关（r=-0.17，p<0.001），但与性别无关。仅在 54 个样本（12%）中发现 25-OHD 水平充足（≥30ng/mL）。在 13 名受试者中观察到明显的季节性 25-OHD 变化（p<0.05）。此外，在 2010 年 2 月至 2011 年 10 月期间采集的样本中观察到明显的季节性波动（p≤0.01）。患有糖尿病（19±9 与 14±7ng/mL，p<0.01）和高血压（20±9 与 17±9ng/mL，p<0.01）的患者 25-OHD 浓度较低。此外，25-OHD 与 BMI 呈负相关（r=-0.25，p<0.001）。相反，吸烟习惯和血脂异常对 25-OHD 水平没有影响。在多变量逻辑回归模型中，年龄是低 25-OHD 水平的唯一显著独立危险因素（优势比，95%置信区间：3.1，1.3-7.3；p≤0.01）。
结果证实 LIAISON 25-OHD 测定法是临床实践中 25-OHD 估计的有用工具。意大利成年人缺乏维生素 D 很常见，并且似乎与多种心血管危险因素有关。
