Raffner Basson Abigail, Swart Rina, Jordaan Esme, Mazinu Mikatako, Watermeyer Gillian
a Dietetics Department.
b Statistics and Population Studies Department.
J Am Coll Nutr. 2016;35(2):163-74. doi: 10.1080/07315724.2015.1039665. Epub 2015 Oct 2.
Vitamin D has immunoregulatory properties and appears to influence disease outcomes in patients with Crohn's disease (CD). The primary aim of this study was to evaluate the association between vitamin D status and CD activity in South Africa.
In a cross-sectional study performed between September 2011 and January 2013, serum 25-hydroxyvitamin D (25(OH)D) was measured in 186 consecutive patients with CD seen at 2 inflammatory bowel disease (IBD) centers and 199 healthy controls in the Western Cape, South Africa. Lifestyle and clinical variables were identified using an investigator-administered questionnaire, as well as clinical examination and patient case notes. Vitamin D status was evaluated in 2 ways: ≤ 20 ng/mL vs ≥ 21 ng/mL and ≤ 29 ng/mL vs ≥ 30 ng/mL. Disease activity was measured by the Harvey Bradshaw Index (HBI). Various 25(OH)D threshold concentrations for predicting a higher HBI score were also investigated.
On multiple log-binomial regression analysis, higher HBI scores and not having taken vitamin D supplementation in the 6 months prior to enrollment were identified as risk factors for vitamin D deficiency in patients with CD, defined either as ≤ 20 ng/mL or as ≤ 29 ng/mL (p < 0.03). Compared to patients with HBI < 5, those with HBI ≥ 8 were 2.5 times more likely to have 25(OH)D concentrations ≤ 21 ng/mL (prevalence risk [PR] = 2.5; 95% confidence interval [CI], 1.21-6.30). The risk was similar, though not as high, when defined as ≤ 29 ng/mL (PR = 2.0; 95% CI, 1.13-3.51). When vitamin D deficiency was defined as <20, <30, <40, and <50 ng/mL, the sensitivity and specificity obtained were 44.9% and 78.8%; 75.5% and 62.4%; 86.7% and 44.7%; and 92.9% and 23.5%, respectively (area under the curve = 0.71; p < 0.0001).
Low serum 25(OH)D was associated with increased CD activity in a South African cohort.
维生素D具有免疫调节特性，似乎会影响克罗恩病（CD）患者的疾病转归。本研究的主要目的是评估南非维生素D状态与CD活动度之间的关联。
在2011年9月至2013年1月进行的一项横断面研究中，对在南非西开普省的2个炎症性肠病（IBD）中心就诊的186例连续性CD患者及199例健康对照者检测了血清25-羟基维生素D（25(OH)D）。通过研究者填写的问卷、临床检查及患者病历确定生活方式和临床变量。维生素D状态通过两种方式评估：≤20 ng/mL与≥21 ng/mL，以及≤29 ng/mL与≥30 ng/mL。采用哈维·布拉德肖指数（HBI）测量疾病活动度。还研究了用于预测较高HBI评分的各种25(OH)D阈值浓度。
在多对数二项回归分析中，较高的HBI评分以及在入组前6个月未补充维生素D被确定为CD患者维生素D缺乏的危险因素，维生素D缺乏定义为≤20 ng/mL或≤29 ng/mL（p<0.03）。与HBI<5的患者相比，HBI≥8的患者25(OH)D浓度≤21 ng/mL的可能性高2.5倍（患病风险[PR]=2.5；95%置信区间[CI]，1.21 - 6.30）。当定义为≤29 ng/mL时，风险相似但没那么高（PR = 2.0；95% CI，1.13 - 3.51）。当维生素D缺乏定义为<20、<30、<40和<50 ng/mL时，获得的敏感性和特异性分别为44.9%和78.8%；75.5%和62.4%；86.7%和44.7%；以及92.9%和23.5%（曲线下面积 = 0.71；p<0.0001）。
在南非队列中，低血清25(OH)D与CD活动度增加相关。
