Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.
School of Population Health, University of Auckland, Auckland, New Zealand.
Nutr Rev. 2018 May 1;76(5):380-394. doi: 10.1093/nutrit/nux077.
Vitamin D has been proposed to have anti-inflammatory properties; however, the effect of vitamin D supplementation on inflammation in type 2 diabetes has not been established.
The aim of this systematic review and meta-analysis was to examine the effect of vitamin D supplementation on inflammatory markers in patients with type 2 diabetes and to identify relevant gaps in knowledge.
MEDLINE, CINAHL, Embase, and EBM Reviews were searched systematically from inception to January 25, 2017.
Randomized controlled trials (RCTs) investigating the effects of vitamin D supplementation (any form, route, and duration, and with any cosupplementation) compared with placebo or usual care on inflammatory markers in patients with type 2 diabetes were selected.
Study and sample characteristics and aggregate outcome data were extracted, risk of bias was determined, and quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.
Twenty-eight RCTs were included, 20 of which had data available for pooling. In meta-analyses of 20 RCTs (n = 1270 participants), vitamin D-supplemented groups had lower levels of C-reactive protein (standardized mean difference [SMD] -0.23; 95%CI, -0.37 to -0.09; P = 0.002) and tumor necrosis factor α (SMD -0.49; 95%CI, -0.84 to -0.15; P = 0.005), a lower erythrocyte sedimentation rate (SMD -0.47; 95%CI, -0.89 to -0.05; P = 0.03), and higher levels of leptin (SMD 0.42; 95%CI, 0.04-0.81; P = 0.03) compared with control groups. No differences were observed for adiponectin, interleukin 6, or E-selectin (all P > 0.05). In meta-regression and subgroup analyses, age, sex, body mass index, duration of diabetes, baseline vitamin D status, and dose and duration of supplementation did not alter the results.
This meta-analysis provides level 1 evidence that vitamin D supplementation may reduce chronic low-grade inflammation in patients with type 2 diabetes.
PROSPERO CRD42016047755. Available at: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=47755 (9/15/2016).
维生素 D 具有抗炎特性；然而，维生素 D 补充剂对 2 型糖尿病患者的炎症影响尚未确定。
本系统评价和荟萃分析旨在研究维生素 D 补充剂对 2 型糖尿病患者炎症标志物的影响，并确定相关知识空白。
从建库到 2017 年 1 月 25 日，系统检索了 MEDLINE、CINAHL、Embase 和 EBM Reviews 数据库。
选择了随机对照试验（RCT），这些试验调查了维生素 D 补充剂（任何形式、途径和持续时间，以及任何伴随补充剂）与安慰剂或常规护理相比对 2 型糖尿病患者炎症标志物的影响。
提取了研究和样本特征以及综合结果数据，使用 Grading of Recommendations, Assessment, Development, and Evaluation（GRADE）方法确定了偏倚风险，并评估了证据质量。
共纳入 28 项 RCT，其中 20 项 RCT 有可用数据进行汇总分析。在对 20 项 RCT（n=1270 名参与者）的荟萃分析中，维生素 D 补充组的 C 反应蛋白水平较低（标准化均数差 [SMD] -0.23；95%CI，-0.37 至-0.09；P=0.002）和肿瘤坏死因子-α（SMD -0.49；95%CI，-0.84 至-0.15；P=0.005），红细胞沉降率较低（SMD -0.47；95%CI，-0.89 至-0.05；P=0.03），瘦素水平较高（SMD 0.42；95%CI，0.04-0.81；P=0.03），与对照组相比。脂联素、白细胞介素 6 或 E-选择素均无差异（均 P>0.05）。在多元回归和亚组分析中，年龄、性别、体重指数、糖尿病病程、基线维生素 D 状态以及补充剂量和时间均未改变结果。
本荟萃分析提供了 1 级证据，表明维生素 D 补充可能降低 2 型糖尿病患者的慢性低度炎症。
PROSPERO CRD42016047755。可在以下网址获得：https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=47755（2016 年 9 月 15 日）。
