Internal Medicine, Sykehuset Ostfold HF, Sarpsborg, Norway
Health Sciences, Østfold University College, Fredrikstad, Norway.
BMJ Open. 2020 Feb 6;10(2):e034935. doi: 10.1136/bmjopen-2019-034935.
In rheumatoid arthritis (RA), fatigue is an important complaint with a significant impact on quality of life. Vitamin D has modulatory effects on cells of the immune system and may potentially affect RA disease activity and thereby RA-related fatigue. The purpose of this study was to explore associations between fatigue and vitamin D status in patients with RA.
Hypothesis-generating cross-sectional study.
Scheduled follow-up visits at a hospital-based general rheumatology clinic.
Patients (n=169) with established RA.
Fatigue, assessed by the Chalder fatigue questionnaire, and serum concentrations of 25-hydroxyvitamin D (25(OH)D), assessed by liquid chromatography-tandem mass spectrometry. Associations were analysed by correlation, and multivariate linear regression with adjustments for age, sex, body mass index, RA disease activity as measured by the Disease Activity Score 28-joint count C reactive protein (DAS28-CRP), psychological distress, pain and sleep. Fatigue was also compared across four groups based on the levels of serum 25(OH)D with cut points at 30, 50 and 75 nmol/L using one-way analysis of variance.
Two-thirds of the patients (116/169, 69%) were classified with low RA disease activity, that is, a DAS28-CRP score below 3.2. Their mean (SD) serum 25(OH)D concentration was 56.3 (21.2) nmol/L, with 77 (45.6%) having values below 50 nmol/L and 12 patients (7.1%) below 30 nmol/L. The correlation between fatigue and serum concentrations of 25(OH)D was weak and not statistically significant, r = -0.14 (95% CI: -0.29 to 0.03, p=0.08). In the multivariate model, fatigue was significantly associated with RA disease activity, psychological distress and pain, but not with serum 25(OH)D. Fatigue did not differ across groups with varying levels of serum 25(OH)D.
This cross-sectional study found no evidence of association between vitamin D and fatigue in patients with RA.
在类风湿关节炎（RA）中，疲劳是一种重要的主诉，对生活质量有重大影响。维生素 D 对免疫系统的细胞具有调节作用，可能会影响 RA 的疾病活动，从而影响与 RA 相关的疲劳。本研究的目的是探讨 RA 患者疲劳与维生素 D 状态之间的关系。
生成假设的横断面研究。
医院基础普通风湿病科的定期随访就诊。
已确诊的 RA 患者（n=169）。
疲劳，使用 Chalder 疲劳问卷评估；血清 25-羟维生素 D（25(OH)D）浓度，使用液相色谱-串联质谱法评估。通过相关性分析和调整年龄、性别、体重指数、疾病活动评分 28 关节计数 C 反应蛋白（DAS28-CRP）、心理困扰、疼痛和睡眠后进行多变量线性回归分析。根据血清 25(OH)D 水平将患者分为四组，以 30、50 和 75 nmol/L 为截断点，采用单因素方差分析比较各组间的疲劳差异。
三分之二的患者（169 例中有 116 例，69%）被归类为低 RA 疾病活动，即 DAS28-CRP 评分低于 3.2。他们的平均（SD）血清 25(OH)D 浓度为 56.3（21.2）nmol/L，其中 77 例（45.6%）的浓度低于 50 nmol/L，12 例（7.1%）的浓度低于 30 nmol/L。疲劳与血清 25(OH)D 浓度之间的相关性较弱且无统计学意义，r=-0.14（95%CI：-0.29 至 0.03，p=0.08）。在多变量模型中，疲劳与 RA 疾病活动、心理困扰和疼痛显著相关，但与血清 25(OH)D 无关。不同血清 25(OH)D 水平组的疲劳无差异。
本横断面研究未发现 RA 患者维生素 D 与疲劳之间存在关联。
