Association of the vitamin D binding protein polymorphisms with the risk of type 2 diabetes mellitus: a meta-analysis

Abstract

ObjectivePrevious studies on the association between vitamin D binding protein (DBP) polymorphisms and the risk of type 2 diabetes mellitus (T2DM) have produced conflicting results. The purpose of this meta-analysis was to examine whether DBP polymorphisms are associated with the risk of T2DM.DesignSystematic review and meta-analysis.MethodsAll eligible studies were searched and acquired from the Cochrane, Pubmed, ISI, CNKI (Chinese) and Wanfang (Chinese) databases. ORs with corresponding 95% CIs were computed to estimate the association between DBP polymorphisms and T2DM. In addition, heterogeneity test, meta-regression and sensitivity analysis were also conducted.ResultsSix studies, which included 1191 cases and 882 controls, met the inclusion criteria and were included in the meta-analysis. The results showed that no significant associations were found between codon 416 and codon 420 polymorphisms in the DBP and the risk of T2DM in the overall analyses. In stratified analysis, significant associations between the codon 420 polymorphism and T2DM were found in Asians (allele Lys vs Thr: OR (95% CI) 1.49 (1.19 to 1.85), genotype Lys/Thr versus Thr/Thr: OR (95% CI) 1.80 (1.36 to 2.38), and Lys/Thr+Lys/Lys versus Thr/Thr: OR (95% CI) 1.81 (1.37 to 2.39), respectively) but not in Caucasians. For the codon 416, the significant association with T2DM was also detected in Asians (genotype Glu/Asp+Glu/Glu vs Asp/Asp: OR (95% CI) 1.36 (1.04 to 1.78)) but not in Caucasians.ConclusionsThis meta-analysis demonstrated that the DBP polymorphism was moderately associated with increased susceptibility to T2DM in Asians, but a similar association was not found in Caucasians. It suggested that ethnicity might be the potential factor associated with heterogeneity.

Single‐cell transcriptomes reveal characteristic features of human pancreatic islet cell types

“…However, two genes— GC and DLK1 —that are among the most characteristic for human alpha and beta cells, respectively, are expressed in opposite patterns in the mouse. Both DLK1 and GC are relevant to diabetes , and further research is necessary to dissect their roles in both human and mouse islet biology.…”

Behind the scenes of vitamin D binding protein: More than vitamin D binding

“…A recent meta-analysis showed a moderate association of the DBP polymorphism with increased susceptibility to diabetes type 2 in Asians, but not in Caucasians. The following potential underlying reasons for this association have been proposed: (1) impact on the metabolite of vitamin D, affecting the amount and activity of vitamin D in the b cell, (2) impact on fatty acids, which may induce b cell abnormalities, (3) immunomodulation of DBP(-MAF) with influence on several cytokines and (4) variations in a closely linked gene on chromosome 4q12 [68]. The altered expression of DBP has also been observed in other autoimmune diseases with underlying vitamin D (un)related working mechanisms such as rheumatoid arthritis and [69] and granulomatosis with polyangiitis [26].…”

MANAGEMENT OF ENDOCRINE DISEASE: The effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

“…(46,47). In addition, a study by Wang et al demonstrated that the vitamin D-binding protein polymorphism, and thus vitamin D bioavailability, was moderately associated with increased susceptibility to type 2 diabetes in Asians, but not in Caucasians, suggesting that ethnicity might be a potential factor associated with heterogeneity (48).…”