Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Metabolic Disorders Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
Pharmacol Rep. 2019 Apr;71(2):282-288. doi: 10.1016/j.pharep.2018.12.012. Epub 2018 Dec 28.
After the onset of type 1 diabetes mellitus (T1DM), preservation of the residual ß-cell function can help good metabolic control. The aim of this study was to evaluate the effect of vitamin D and its receptor gene polymorphisms on residual ß-cells function.
One hundred and one children with T1DM (new cases) older than 5 years were selected. Vitamin D receptor (VDR) gene polymorphisms, vitamin D (VD), fasting and stimulated C-peptide (FCP and SCP) levels were measured within 1.5 and 4.5 month after the diagnosis of disease. Kruskal-Wallis and Mann-whitney U test were used for comparing the study groups. Generalized estimating equation (GEE) model was used for the estimation of association between VD and VDR gene polymorphisms with FCP and SCP after adjustment for comorbid variables.
The most frequent genotypes and alleles in TaqI, FokI, BsmI and ApaI polymorphisms were TT (50%) and allele T (68.88%), FF (59.2%) and allele F (77.04%), Bb (41.8%) and allele b (61.73%), and Aa (53.1%) and allele A (63.29%) respectively. In children with higher VD levels, the C-peptide (CP) levels were elevated. Also we observed: the tt genotype associated with increasing SCP levels compared with TT genotype; the bb and Bb genotypes were associated with increasing both FCP and SCP in comparison to BB; and the aa and Aa genotypes were associated with decreasing FCP in comparison to the AA genotype.
Sufficient levels of VD (more than 30 ng/ml) can preserve residual ß-cells and insulin secretion.
1 型糖尿病（T1DM）发病后，保留残余β细胞功能有助于良好的代谢控制。本研究旨在评估维生素 D 及其受体基因多态性对残余β细胞功能的影响。
选择 101 例年龄大于 5 岁的新诊断为 T1DM 的儿童。在发病后 1.5 个月和 4.5 个月内测量维生素 D 受体（VDR）基因多态性、维生素 D（VD）、空腹和刺激 C 肽（FCP 和 SCP）水平。Kruskal-Wallis 和 Mann-Whitney U 检验用于比较研究组。采用广义估计方程（GEE）模型校正合并变量后，评估 VD 与 VDR 基因多态性与 FCP 和 SCP 的相关性。
TaqI、FokI、BsmI 和 ApaI 多态性中最常见的基因型和等位基因分别为 TT（50%）和 T 等位基因（68.88%）、FF（59.2%）和 F 等位基因（77.04%）、Bb（41.8%）和 b 等位基因（61.73%）、以及 Aa（53.1%）和 A 等位基因（63.29%）。在 VD 水平较高的儿童中，C 肽（CP）水平升高。此外，我们还观察到：与 TT 基因型相比，tt 基因型与 SCP 水平升高相关；与 BB 基因型相比，bb 和 Bb 基因型与 FCP 和 SCP 均升高相关；与 AA 基因型相比，aa 和 Aa 基因型与 FCP 降低相关。
VD （超过 30ng/ml）充足水平可保留残余β细胞并促进胰岛素分泌。
