Correlations between Serum 25-Hydroxyvitamin D and Pancreatic Islet Function in Type 2 Diabetics

Abstract Background Vitamin D deficiency has been associated with type 2 diabetes (T2D) and metabolic syndrome (MS) and its components. However, it is unclear whether a low concentration of vitamin D is the cause or consequence of these health conditions. Thus, this study aimed to evaluate the association of vitamin D concentrations and its genetic risk scores (GRSs) with MS and its component diseases, such as T2D, in middle-aged and elderly participants from rural eastern China. Methods A subset of 2393 middle-aged and elderly individuals were selected from 70,458 participants of the Nantong Chronic Diseases Study of 2017–2018 in China. We used two 25-hydroxyvitamin D (25[OH]D) synthesis single-nucleotide polymorphisms (SNPs) (DHCR7-rs12785878 and CYP2R1-rs10741657) and two 25(OH) D metabolism SNPs (GC-rs2282679 and CYP24A1-rs6013897) for creating GRSs, which were used as instrumental variables to assess the effect of genetically lowered 25(OH) D concentrations on MS and T2D based on the Wald ratio. F statistics were used to validate that the four SNPs genetically determined 25(OH) D concentrations. Results Compared to vitamin D sufficient individuals, individuals with vitamin D insufficiency had an odds ratio (OR [95% confidence interval {CI}]) of MS of 1.30 (1.06–1.61) and of T2D of 1.32 (1.08–1.64), individuals with vitamin D deficiency had an ORs (95% CI) of MS of 1.50 (1.24–1.79) and of T2D of 1.47 (1.12–1.80), and those with vitamin D severe deficiency had an ORs (95% CI) of MS of 1.52 (1.29–1.85) and of T2D of 1.54 (1.27–1.85). Mendelian randomization analysis showed a 25-nmol/L decrease in genetically instrumented serum 25(OH) D concentrations using the two synthesis SNPs (DHCR7 and CYP2R1 genes) associated with the risk of T2D and abnormal diastolic blood pressure (DBP) with ORs of 1.10 (95%CI: 1.02–1.45) for T2D and 1.14 (95%CI: 1.03–1.43) for DBP. Conclusions This one sample Mendelian randomization analysis shows genetic evidence for a causal role of lower 25(OH) D concentrations in promoting of T2D and abnormal DBP in middle-aged and elderly participants from rural China.

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Correlational study on the levels of 25-hydroxyvitamin D and non-alcoholic fatty liver disease in type 2 diabetic patients

BMC Endocrine Disorders ◽

10.1186/s12902-021-00762-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yuanyuan Zhang ◽

Juyi Li ◽

Yingqun Ni ◽

Yan Wang ◽

Huaizhen Liu

Keyword(s):

Liver Disease ◽

Liver Fibrosis ◽

Fatty Liver ◽

Fatty Liver Disease ◽

Diabetic Patients ◽

Type 2 Diabetic Patients ◽

Hydroxyvitamin D ◽

25 Hydroxyvitamin D ◽

Type 2 Diabetic

Abstract Background It is widely acknowledged that nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus(T2DM) are all chronic metabolic diseases. The objective of this study is to retrospectively probe the association between the 25-hydroxyvitamin D (25-(OH)D) and NAFLD in type 2 diabetic patients. Methods Three hundred thirty-nine T2DM patients participated in this research and from November 2018 to September 2019 and were divided into simple T2DM group (108 cases) and T2DM with NAFLD group (231 cases) in conformity with abdominal ultrasound diagnosis. The NAFLD fibrosis score (NFS) ≥0.676 was defined as progressive liver fibrosis.231 T2DM with NAFLD patients were categorized into two subgroups: progressive liver fibrosis subgroup (48 cases) and without progressive liver fibrosis subgroup (183 cases). Results The prevalence of NAFLD by Abdominal ultrasonography was 68%.The results indicated that the levels of 25-(OH) D were significantly lower in T2DM with NAFLD group than that in simple T2DM group(P < 0.01). The levels of 25-(OH) D were significantly lower in progressive liver fibrosis subgroup than that in patients without progressive liver fibrosis and simple T2DM,and 25-(OH) D levels were lower in without progressive liver fibrosis subgroup than that in simple T2DM group(p < 0.01 or p < 0.05). Multivariate logistic regression analysis showed that levels of 25-(OH) D were negative correlation with risk of NAFLD and progressive liver fibrosis(p = 0.011、p = 0.044,respectively). Conclusions we could come to a conclusion that low levels of 25-(OH) D was a risk factor for NAFLD and progressive liver fibrosis in T2DM patients.

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