Zhang Yan, Jing Danrong, Zhou Guowei, Xiao Yi, Shen Minxue, Chen Xiang, Liu Hong
Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China.
Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China.
Front Nutr. 2022 Jul 25;9:807344. doi: 10.3389/fnut.2022.807344. eCollection 2022.
Plenty of observational studies suggested that vitamin D concentrations were associated with psoriasis, but the causality of this relationship was elusive.
To investigate the causal relationship between vitamin D and psoriasis.
Cox proportional hazard model was used to investigate the association between vitamin D status and psoriasis in a prospective cohort study from UK Biobank. Single nucleotide polymorphisms (SNPs) that are strongly associated with circulating 25OHD were constructed as instrumental variables in Mendelian randomization (MR) to determine the causality between vitamin D and psoriasis.
During a median follow-up of 10.99 years, we identified 2,856 participants with incident psoriasis. The prospective cohort study demonstrated individuals with 25OHD deficiency (< 25 nmol/L) at baseline were associated with approximately 20% increased risk of incident psoriasis in different categories of sex, age, and body mass index (BMI) after adjusting for covariates. The largest effect size was observed in the obese group (BMI > 30 kg/m), as 25OHD deficiency presented with 30% additional risk of incident psoriasis compared to those with 25OHD > 50 nmol/L (HR = 0.701; 95% CI: 0.583-0.843; < 0.001). Additionally, 69 independent SNPs associated with circulating 25OHD level were selected for the MR analysis, and the result suggested that genetically predicted one standard deviation (SD) increment in log-transformed 25OHD was associated with 24% decreased risk of psoriasis (OR = 0.76; 95% CI: 0.60-0.98, = 0.020).
The association of 25OHD and severity of psoriasis could not be estimated in the current study.
The combined prospective and MR analysis additionally provided evidence that the epidemiologically and genetically determined level of 25OHD conferred an increased risk of psoriasis.
大量观察性研究表明维生素D浓度与银屑病有关，但这种关系的因果性尚不清楚。
探讨维生素D与银屑病之间的因果关系。
在英国生物银行的一项前瞻性队列研究中，采用Cox比例风险模型研究维生素D状态与银屑病之间的关联。将与循环25羟维生素D（25OHD）密切相关的单核苷酸多态性（SNP）构建为孟德尔随机化（MR）中的工具变量，以确定维生素D与银屑病之间的因果关系。
在中位随访10.99年期间，我们确定了2856例新发银屑病患者。前瞻性队列研究表明，在调整协变量后，基线时25OHD缺乏（<25 nmol/L）的个体在不同性别、年龄和体重指数（BMI）类别中发生银屑病的风险增加约20%。在肥胖组（BMI>30 kg/m²）中观察到最大效应量，与25OHD>50 nmol/L的个体相比，25OHD缺乏者发生银屑病的额外风险为30%（风险比[HR]=0.701；95%置信区间[CI]：0.583-0.843；P<0.001）。此外，选择69个与循环25OHD水平相关的独立SNP进行MR分析，结果表明，基因预测的log转换后25OHD每增加一个标准差（SD），银屑病风险降低24%（比值比[OR]=0.76；95%CI：0.60-0.98，P=0.020）。
本研究无法估计25OHD与银屑病严重程度之间的关联。
前瞻性研究和MR分析相结合进一步提供了证据，表明流行病学和遗传学确定的25OHD水平会增加患银屑病的风险。
