Dipartimento di Medicina Clinica e Sperimentale, Via Solaroli 17, Novara, Italy.
Rheumatology (Oxford). 2011 Dec;50(12):2290-6. doi: 10.1093/rheumatology/ker314. Epub 2011 Oct 22.
To verify if autoimmune/inflammatory rheumatic disease (ARD) patients were more refractory to PTH suppression by 25(OH) vitamin D (VITD).
Data from 105 consecutive ARD patients (including RA, PMR, spondyloarthritis and other CTDs) attending a tertiary-level immuno-rheumatology clinic and 1542 subjects tested at our central laboratory from 2008 to 2010 (controls) were collected. After exclusion of patients with renal failure, primary hyperparathyroidism and hypercalcaemia (n = 522), plasma VITD, PTH, calcium and phosphate concentrations were compared between these two groups.
Plasma VITD concentrations were <25 nmol/l in 257 patients (severe deficit, 22.8%), ≥25 nmol/l but <75 nmol/l in 661 (mild deficit, 58.8%) and ≥ 75 nmol/l in 207 (normal, 18.4%). Despite similar median age, plasma VITD, calcium and phosphate values (P = 0.96, 0.30, 0.94, respectively), PTH was higher in ARD {73.0 [interquartile range (IQR) 54.2-93.7] pg/ml} than in controls [61.4 (46.9-80.3), P < 0.0002], also in all above-defined VITD categories (P < 0.05). Suppressed PTH was observed in 96.9% (95% CI 95.8%, 98.0%) of controls with VITD ≥ 75 nmol/l. However, PTH was increased more frequently in ARD vs controls. At multiple linear regression analysis, plasma VITD, age and the presence of an ARD (partial correlation coefficients -0.21, 0.15, 0.12, respectively, P < 0.0001) were independent predictors for increased PTH.
Patients with ARD had, on average, an increased PTH concentration for any plasma VITD range, suggesting an impaired vitamin D metabolism. Therefore, vitamin D supplementation to ARD patients may be targeted to reach PTH suppression and not simply to obtain VITD concentrations considered optimal in other categories of patients.
验证自身免疫性/炎症性风湿病（ARD）患者对 25（OH）维生素 D（VITD）的抑制作用是否更差。
收集了 2008 年至 2010 年在我们的三级免疫风湿病诊所就诊的 105 例连续 ARD 患者（包括 RA、PMR、脊柱关节炎和其他 CTD）的数据（n=105），以及在我们的中心实验室检测的 1542 例受试者的数据（对照组，n=1542）。排除肾衰竭、原发性甲状旁腺功能亢进和高钙血症患者（n=522）后，比较两组患者的血浆 VITD、PTH、钙和磷浓度。
257 例患者的血浆 VITD 浓度<25nmol/L（严重缺乏，22.8%），661 例患者的血浆 VITD 浓度≥25nmol/L 但<75nmol/L（轻度缺乏，58.8%），207 例患者的血浆 VITD 浓度≥75nmol/L（正常，18.4%）。尽管中位年龄、血浆 VITD、钙和磷值相似（P=0.96、0.30、0.94，分别），但 ARD 患者的 PTH 更高[73.0（四分位距 54.2-93.7）pg/ml]，对照组[61.4（46.9-80.3），P<0.0002]，且在所有上述定义的 VITD 类别中（P<0.05）均如此。在 VITD≥75nmol/L 的对照组中，96.9%（95%CI 95.8%，98.0%）患者的 PTH 得到抑制。然而，与对照组相比，ARD 患者的 PTH 升高更为常见。在多元线性回归分析中，血浆 VITD、年龄和 ARD 的存在（偏相关系数-0.21、0.15、0.12，P<0.0001）是 PTH 升高的独立预测因素。
无论血浆 VITD 范围如何，ARD 患者的 PTH 浓度平均升高，提示维生素 D 代谢受损。因此，针对 ARD 患者的维生素 D 补充可能是为了达到 PTH 抑制作用，而不仅仅是获得在其他患者类别中被认为是最佳的 VITD 浓度。
