Vitamin D Reduces the Activity of Adenosine Deaminase and Oxidative Stress in Patients with Type Two Diabetes Mellitus.

SCOPE: Patients with Type 2 diabetes mellitus (T2DM) have lower levels of vitamin D. An elevation in uric acid (UA) contributes to T2DM via an increase in oxidative stress. Adenosine deaminase (ADA) is an enzyme of the purine degradation pathway. It is hypothesized that a reduction of ADA activity via vitamin D supplementation reduces UA and oxidative stress. METHODS AND RESULTS: A total of 162 participants (81 with T2DM and 81 controls) are enrolled in a case-control study. A follow-up interventional study is performed on 30 patients with vitamin D deficiency. These patients receive 50 000 IU (international units) of vitamin D3 on a weekly basis for 12 weeks. This intervention is followed by the measurement of several markers. T2DM patients has higher ADA activity, UA, and lipid peroxidation but lower 25-hydroxy-vitamin D (25 (OH) vitamin D) and GSH/GSSG ratio (p < 0.05). Vitamin D supplementation results in a reduction of ADA activity and UA levels (p < 0.05) along with an increase in GSH/GSSG ratio (p < 0.05). CONCLUSION: The results highlight the presence of an axis in T2DM patients between ADA, UA, and oxidative stress. Modulation of this axis can be achieved by clinically approved vitamin D supplementation protocols.

Serum Leptin Receptor and the rs1137101 Variant of the LEPR Gene Are Associated with Bladder Cancer.

Globally, bladder cancer (BC) is one of the ten most common tumors. Obesity is a worldwide problem associated with an increased BC risk. Considering that levels of leptin and/or its receptor are often deregulated in obese individuals, we hypothesized that they could contribute to BC. To test this hypothesis, we utilized a case-control study in which 116 patients with a confirmed diagnosis of BC and 116 controls were recruited. The serum levels of leptin and leptin receptor were measured. Patients and controls were also genotyped for SNPs in the LEP (rs7799039, rs791620, and rs2167270) and LEPR genes (rs1137100, rs1137101, and rs1805094). The univariate analysis indicated that BC patients had significantly higher levels of leptin and lower levels of leptin receptor (p < 0.05). Moreover, rs7799039 of LEP and rs1137101 of LEPR were associated with BC (p < 0.05). In the multivariate analysis, leptin receptor levels were protective (OR: 0.98, 95% CI = 0.97-0.99, p = 0.002) while the GG genotype of rs1137101 of LEPR increased BC risk (OR: 3.42, 95% CI = 1.27-9.20, p = 0.02). These findings highlight that lifestyle changes could be useful in preventing BC and that disturbances in energy metabolism could play a role in the pathobiology of BC.

Genetic variation in the ADIPOQ gene and serum adiponectin increase the risk of bladder cancer.

Bladder cancer (BC) is the 10th most common cancer worldwide. Genetic studies estimated 30% heritability in BC risk. Adiponectin is an adipocytokine that has important roles in the regulation of energy metabolism. Recent evidence suggests dysregulation of adiponectin levels in BC tissues. Serum level of adiponectin is influenced by single nucleotide polymorphisms (SNPs) in the ADIPOQ gene. However, limited evidence is available regarding the association between adiponectin serum levels or SNPs in ADIPOQ and BC risk. This study aimed to assess whether adiponectin serum levels or SNPs in ADIPOQ may modify BC risk. In this case-control study, 114 BC patients were recruited along with 114 controls. Study subjects were genotyped for variations in ADIPOQ SNPs, namely rs17300539, rs266729, rs2241766, and rs1501299. Adiponectin levels were measured from the serum of study subjects. Our analysis showed that the G allele and the GG genotype of rs1501299 were significantly more frequent in BC patients compared to those in the control group (p-value < 0.05). Moreover, two ADIPOQ haplotypes containing the above G allele were associated with increased BC risk (p-value < 0.05). Multivariate analysis showed that increased serum adiponectin, smoking or age were all significant predictors of BC (p-value < 0.05). The data supports use of serum adiponectin and the G allele of rs1501299 SNP in ADIPOQ as potential biomarkers and/or targets in BC. To further validate findings in this study, larger populations of various ethnicities and/or genetic backgrounds are required. More investigations on the functional role of adiponectin in BC will also provide better understanding of potential targeting adiponectin for BC treatment.

Single Nucleotide Polymorphism in the ADIPOQ Gene Modifies Adiponectin Levels and Glycemic Control in Type Two Diabetes Mellitus Patients.

Diabetes mellitus (DM) is the ninth leading cause of death worldwide. Mortality from DM is largely attributed to disease complications. Glycemic control of DM patients reduces mortality. Studies indicated that the lack of glycemic control in DM patients could be influenced by the genetic background of the patients. Evidence suggests that adiponectin levels are dysregulated in DM patients with poor glycemic control. Serum adiponectin level is a heritable trait influenced by single nucleotide polymorphisms (SNPs) in the ADIPOQ gene. It is hypothesized that SNPs in ADIPOQ could modify glycemic control in DM patients. To test this hypothesis, 375 type 2 DM (T2DM) patients were recruited. Patients were classified into good vs. poor glycemic control according to hemoglobin A1c levels. Study subjects were genotyped for variations of four SNPs in ADIPOQ (rs17300539, rs266729, rs2241766, and rs1501299). Adiponectin levels were measured from the serum. Our analysis showed that reduced serum adiponectin, a longer duration of treatment, and increased insulin resistance were all significant predictors of poor glycemic control. Moreover, the T allele and the TT genotype of rs2241766 were significantly more frequent in patients with poor glycemic control (P < 0.05). Individuals with the TT genotype of rs2241766 had significantly lower levels of serum adiponectin (P < 0.05). It was concluded that lower levels of serum adiponectin and the T allele of rs2241766 SNP in ADIPOQ were associated with poor glycemic control in T2DM patients.