Association of vitamin D receptor gene polymorphisms with type 2 diabetes mellitus in Taif population: a case-control study

Abstract

Several reasons may underlie the dramatic increase in type2 diabetes mellitus. One of these reasons is the genetic basis and variations. Vitamin D receptor polymorphisms are associated with different diseases such as rheumatoid arthritis and diabetes. The aim of this study is to investigate the possible association of two identified mutations ApaI (rs7975232) and TaqI (rs731236). Eighty-nine healthy individuals and Fifty-six Type 2 Diabetic (T2D) patients were investigated using RFLP technique for genotyping and haplotyping as well. The distribution of Apal genotypes was not statistically significant among the control (P=0.65) as well as for diabetic patients (P=0.58). For Taql allele frequencies of T allele was 0.61 where of G allele was 0.39. The frequency distribution of Taql genotypes was not statistically significant among the control (P=0.26) as well as diabetic patients (P=0.17). Relative risk of the allele T of Apa1 gene is 1.28 and the odds ratio of the same allele is 1.53, while both estimates were < 1.0 of the allele G. Similarly, with the Taq1 gene the relative risk and the odds ratio values for the allele T are 1.09 and 1.27 respectively and both estimates of the allele C were 0.86 for the relative risk and 0.79 for the odds ratio. The pairwise linkage disequilibrium between the two SNPs Taq1/apa1 was statistically significant in control group (D = 0.218, D' = 0.925 and P value < 0.001) and similar data in diabetic groups (D = 0.2, D' = 0.875 and P value < 0.001). These data suggest that the T allele of both genes Apa1 and Taq1 is associated with the increased risk of type 2 diabetes. We think that we need a larger number of volunteers to reach a more accurate conclusion.

Association Study of Vitamin D Deficiency and its receptor Gene Polymorphism in Diabetic Nephropathy

“…The present study showed that there was a highly significant decrease in ApaI VDR polymorphism (Aa+aa) genotypes in the DM group compared to control and there was a highly significant decrease in (a) allele frequency in the DM group compared to control. In agreement with Alkhedaide et al, who suggested that the (A) allele of ApaI VDR polymorphism was statistically associated with T2DM while the (a) allele of ApaI VDR polymorphism is a protective allele in the Saudi Arabian population (Taif city) [8] . Thus, (aa) is a wild genotype which prevalent with a high percentage in the current study control group and has a high protection effect rather than the (AA) genotype which is prevalent in T2DM patients.…”

Impact of vitamin D receptor polymorphisms in selected metabolic disorders

“…This polymorphism may be associated with a reduced risk of T2D in North American countries and the Caucasian population and may increase the risk of T2D in a mixed population [12 ▪▪ ]. Another study indicates that the T allele of the rs7975232 is associated with the onset of T2D, while the G allele can be regarded as a protective allele [22]. On the other hand, other studies have not shown a relationship between rs7975232 genotypes and T2D [23–25].…”

“…This polymorphism is located near the exon-intron border and therefore may potentially affect the mRNA stability of the VDR gene [20]. A study in a small group of patients with T2D indicates that the T allele of rs731236 may be associated with T2D [22]. Another indicates that rs731236 is not related to glycemic status [23,25,39] but may be related to vitD insufficiency in the South African population [39].…”

Vitamin D Deficiency as a Risk Factor for Diabetes and Poor Glycemic Control in Saudi Arabia: A Systematic Review

“…Table 1 presents the sociodemographic characteristics of the included study articles. Our results included 11 studies with a total of 4229 subjects [21][22][23][24][25][26][27][28][29][30][31]. Two studies were conducted in Arar [30,31], one in the Eastern Region [21], one in Taif [22], one in Jeddah [23], one being multi-centered [24], one in Jazan [25], one in Tabuk [26], one in Al Kharj [27], one in the Southern Region [28], and one in Riyadh [29].…”

“…Our results included 11 studies with a total of 4229 subjects [21][22][23][24][25][26][27][28][29][30][31]. Two studies were conducted in Arar [30,31], one in the Eastern Region [21], one in Taif [22], one in Jeddah [23], one being multi-centered [24], one in Jazan [25], one in Tabuk [26], one in Al Kharj [27], one in the Southern Region [28], and one in Riyadh [29]. Five studies were cross-sectional [23][24][25][26]30], four were case-control studies [21,22,28,31], one was retrospective in nature [27], and one was a randomized controlled trial (RCT) [29].…”