Background Evidence from various studies suggest that vitamin D receptor (VDR) gene polymorphisms are associated with type 2 diabetes (T2D); However, these results have been disputable. Here we conducted a meta-analysis to comprehensively evaluate the effect of VDR gene polymorphisms and susceptibility to T2D. Methods All relevant studies reporting the association between VDR gene polymorphisms and susceptibility to T2D published up to August 2020 were identified by comprehensive systematic database search in web of science, Scopus, and Medline. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure strength of association. The methodological quality of each study was assessed according to the Newcastle-Ottawa Scale. Subgroup and meta-regression analysis were also performed.Results A total of 47 case-control studies were included in this meta-analysis. The overall population results revealed a significant association between FokI, and BsmI (heterozygote model) polymorphisms and T2D in the overall analysis. However, no association was found with the TaqI and ApaI polymorphisms. Moreover, the pooled results of subgroup analysis by ethnicity suggested significant association between FokI, TaqI, and BsmI polymorphisms and T2D in some subgroups. Meta-regression analyses indicated that none of the publication year, ethnicity, and genotyping method were the source of heterogenicity in all four polymorphisms. Conclusions This meta-analysis suggested a significant association between VDR gene FokI, and BsmI (heterozygote model) polymorphisms and T2D susceptibility in overall population and ethnic-specific analysis.

BACKGROUND: Diabetes mellitus (DM) type 2 is the most public chronic, metabolic illness whose prevalence is quickly becoming high international. Insulin resistance, the essential metabolic problem leads to the development of DM type 2, is seen in about 90% of patients. AIM: The study’s aim was to compare the efficacy of three antidiabetic drugs on glycated hemoglobin. METHOD: A cross-sectional comparative study for newly diagnosed type II diabetic patients were assigned randomly into one of three conditions: Group I: Metformin consuming patients, Group II: Pioglitazone consuming patients, and Group III: Vildagliptin consuming patients. All patients were newly diagnosed. For all of them, baseline glycated hemoglobin was requested. After that, random assignment was carried out. After 3 months, glycated hemoglobin was checked and compared. RESULTS: Participants were distributed randomly into 27.9% metformin taking participants, 31.1% pioglitazone taking, and 41% vildagliptin taking patient. Findings suggested significant difference between Groups I and III (p =). Likewise, significant difference was seen between Groups II and III (p =). However, Groups I and II have comparable effects (p =). Indeed, all groups had shown significant efficacy on HbA1c. CONCLUSION: Metformin, pioglitazone, and vildagliptin had shown significant impact on HbA1c with variable degree: Metformin and pioglitazone had shown comparably similar efficacy that was exerted more significant impact on HbA1c than vildagliptin does.