Department of Internal MedicineMedical Centre Alkmaar, Alkmaar, The Netherlands.
Department of Epidemiology and BiostatisticsVU University Medical Centre, Amsterdam, The Netherlands.
Eur J Endocrinol. 2017 Jan;176(1):R1-R14. doi: 10.1530/EJE-16-0391. Epub 2016 Aug 2.
Epidemiologic studies suggest that vitamin D status plays a role in glycaemic control in patients with type 2 diabetes. However, intervention studies yielded inconsistent results. The aim of this study is to systematically review the effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes.
Systematic review and meta-analysis. We searched Medline, Embase and the Cochrane Library for RCTs examining the effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes. A random-effects model meta-analysis was performed to obtain a summarized outcome of vitamin D supplementation on HbA, fasting glucose and homeostasis model assessment - insulin resistance (HOMA-IR).
Twenty-three RCTs were included in this systematic review representing a total of 1797 patients with type 2 diabetes. Mean (± s.d.) change in serum 25-hydroxyvitamin D varied from 1.8 ± 10.2 nmol/L to 80.1 ± 54.0 nmol/L. Nineteen studies included HbA as outcome variable. Combining these studies no significant effect in change of HbA was seen after vitamin D intervention compared with placebo. A significant effect of vitamin D supplementation was seen on fasting glucose in a subgroup of studies (n = 4) with a mean baseline HbA ≥ 8% (64 mmol/mol) (standardized difference in means: 0.36; 95% CI: 0.12-0.61, P = 0.003).
Current evidence of RCTs does not support short-term vitamin D supplementation in a heterogeneous population with type 2 diabetes. However, in patients with poorly controlled diabetes, a favourable effect of vitamin D is seen on fasting glucose.
流行病学研究表明，维生素 D 状态在 2 型糖尿病患者的血糖控制中发挥作用。然而，干预研究得出的结果并不一致。本研究旨在系统评价维生素 D 补充对 2 型糖尿病患者血糖控制的影响。
系统评价和荟萃分析。我们检索了 Medline、Embase 和 Cochrane 图书馆，以查找评估维生素 D 补充对 2 型糖尿病患者血糖控制影响的 RCT。采用随机效应模型荟萃分析，得出维生素 D 补充对 HbA1c、空腹血糖和稳态模型评估 - 胰岛素抵抗（HOMA-IR）的综合结果。
本系统评价共纳入 23 项 RCT，共纳入 1797 例 2 型糖尿病患者。血清 25-羟维生素 D 的平均（±标准差）变化范围为 1.8±10.2 nmol/L 至 80.1±54.0 nmol/L。19 项研究纳入了 HbA1c 作为结局变量。将这些研究结合起来，与安慰剂相比，维生素 D 干预后 HbA1c 的变化没有显著差异。在 HbA1c 基线≥8%（64 mmol/mol）的亚组研究中（n=4），维生素 D 补充有显著的降血糖作用（标准化均数差：0.36；95%CI：0.12-0.61，P=0.003）。
目前 RCT 的证据并不支持在 2 型糖尿病异质人群中短期补充维生素 D。然而，在血糖控制不佳的患者中，维生素 D 有降低空腹血糖的作用。
