Association of Interleukin-6 -174G/C Polymorphism with the Risk of Diabetic Nephropathy in Type 2 Diabetes: A Meta-analysis. Curr Med Sci. 2019;39:250-258. [PMID: 31016518 DOI: 10.1007/s11596-019-2027-1]

IL-6 and diabetic kidney disease

Diabetic kidney disease (DKD) is a severe microvascular complication of diabetes associated with high mortality and disability rates. Inflammation has emerged as a key pathological mechanism in DKD, prompting interest in novel therapeutic approaches targeting inflammatory pathways. Interleukin-6 (IL-6), a well-established inflammatory cytokine known for mediating various inflammatory responses, has attracted great attention in the DKD field. Although multiple in vivo and in vitro studies highlight the potential of targeting IL-6 in DKD treatment, its exact roles in the disease remains unclear. This review presents the roles of IL-6 in the pathogenesis of DKD, including immunoinflammation, metabolism, hemodynamics, and ferroptosis. In addition, we summarize the current status of IL-6 inhibitors in DKD-related clinical trials and discuss the potential of targeting IL-6 for treating DKD in the clinic.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

Associations between the polymorphisms of main components in PI3K/Akt pathway and risk of diabetic kidney disease: A meta-analysis

AIMS

Diabetic kidney disease (DKD) is a severe microvascular complication frequently associated with type 1 and type 2 diabetes mellitus. The objective of this work was to evaluate the relevance of PI3K/Akt pathway polymorphisms and DKD susceptibility by a meta-analysis.

METHODS

Case-control studies related to the relationship between PI3K/Akt pathway polymorphisms and DKD risk were searched from Pubmed, Embase, Cochrane Library, SINOMED, CNKI, and Wanfang databases. Statistical analysis and heterogeneity test were conducted by Review Manager 5.4.

RESULTS

Totally, 52 eligible studies were enrolled, including seven single nucleotide polymorphisms (SNPs) for four genes in the PI3K/AKT pathway (GNB3: rs5443; eNOS: rs1799983, rs869109213, rs2070744; IL-6: rs1800795, rs1800796; TNFα: rs1800629). The "M" allele of eNOS rs1799983 was related to the increased risk of DKD under random effects model, especially in Asian population (Overall:M vs. W: I2  = 75%, OR = 1.29, 95%CI 1.07-1.56; MM + WM vs. WW: I2  = 75%, OR = 1.50, 95%CI 1.21-1.86). The "M" allele of eNOS rs869109213 was implicated with higher prevalence of DKD under random effects model, especially in Asian population (Overall:M vs. W: I2  = 63%, OR = 1.43, 95%CI 1.22-1.68; MM + WM vs. WW: I2  = 50%, OR = 1.36, 95%CI 1.16-1.58; MM vs. WM + WW: I2  = 59%, OR = 2.20, 95%CI 1.41-3.43). The "M" allele of eNOS rs2070744 was implicated with higher prevalence of DKD under random effects model, especially in Indian population (Overall: M vs. W: I2  = 47%, OR = 1.35, 95%CI 1.15-1.59; MM + WM vs. WW: I2  = 45%, OR = 1.32, 95%CI 1.07-1.62; MM vs. WM + WW: I2  = 65%, OR = 2.29, 95%CI 1.39-3.77). The "M" allele of IL-6 rs1800796 was predominately associated with higher DKD risks under random effects model, especially in Asian population (Overall: M versus W: I2  = 23%, OR = 1.49, 95%CI 1.21-1.84; MM + WM vs. WW: I2  = 1%, OR = 1.43, 95%CI 1.15-1.77; MM + WM vs. WW: I2  = 71%, OR = 2.77, 95%CI 1.09-7.06).

CONCLUSIONS

This meta-analysis indicated that polymorphisms in the PI3K/Akt pathway in eNOS rs1799983, rs869109213, rs2070744, and IL-6 rs1800796 were related to the increased risk of DKD.

The impact of angiotensin converting enzyme insertion/deletion gene polymorphism on diabetic kidney disease: A debatable issue

OBJECTIVE

The objective of this study was to evaluate the influence of ACE I/D gene polymorphisms on diabetic kidney disease (DKD) risk.

METHODS

All eligible investigations were identified, the number of various genotype in the case and control group were reviewed. The pooled analysis was performed using Stata software.

RESULTS

In overall subjects, 24,321 participants with 12,961 cases and 11,360 controls were included. the pooled analysis showed a significant link between D allele, DD or II genotype and DKD risk (D versus I: OR=1.316, 95% CI: 1.213-1.427, P=0.000; DD versus ID+II: OR=1.414, 95% CI: 1.253-1.595, P=0.000; II versus DD+ID: OR=0.750, 95% CI: 0.647-0.869, P=0.000). The subgroup pooled analysis showed that ACE I/D gene polymorphism was correlated with DKD both in Asian and in Chinese population. In addition, ACE I/D gene polymorphism was correlated with type 2 DKD (D versus I: OR=1.361, 95% CI: 1.243-1.490, P=0.000; DD versus ID+II: OR=1.503, 95% CI: 1.310-1.726, P=0.000; II versus DD+ID: OR=0.738, 95% CI: 0.626 -0.870, P=0.000). However, there was no obvious correlation in Caucasian subjects and type 1 diabetic patients.

CONCLUSION

ACE I/D polymorphisms were correlated with DKD in Asian and type 2 diabetic populations. ACE D allele/DD genotype might be a risk factor, while ACE II genotype might be a protective factor for DKD.

The impact of angiotensin converting enzyme insertion/deletion gene polymorphism on diabetic kidney disease: A debatable issue

OBJECTIVE

The objective of this study was to evaluate the influence of ACE I/D gene polymorphisms on diabetic kidney disease (DKD) risk.

METHODS

All eligible investigations were identified, the number of various genotype in the case and control group were reviewed. The pooled analysis was performed using Stata software.

RESULTS

In overall subjects, 24,321 participants with 12,961 cases and 11,360 controls were included. the pooled analysis showed a significant link between D allele, DD or II genotype and DKD risk (D versus I: OR=1.316, 95% CI: 1.213-1.427, P=0.000; DD versus ID+II: OR=1.414, 95% CI: 1.253-1.595, P=0.000; II versus DD+ID: OR=0.750, 95% CI: 0.647-0.869, P=0.000). The subgroup pooled analysis showed that ACE I/D gene polymorphism was correlated with DKD both in Asian and in Chinese population. In addition, ACE I/D gene polymorphism was correlated with type 2 DKD (D versus I: OR=1.361, 95% CI: 1.243-1.490, P=0.000; DD versus ID+II: OR=1.503, 95% CI: 1.310-1.726, P=0.000; II versus DD+ID: OR=0.738, 95% CI: 0.626 -0.870, P=0.000). However, there was no obvious correlation in Caucasian subjects and type 1 diabetic patients.

CONCLUSION

ACE I/D polymorphisms were correlated with DKD in Asian and type 2 diabetic populations. ACE D allele/DD genotype might be a risk factor, while ACE II genotype might be a protective factor for DKD.

Suggestive evidence of genetic association of -572G > C polymorphism with primary open angle glaucoma in a North Indian Punjabi population

BACKGROUND

IL6 is an important candidate gene implicated in the pathogenesis of glaucoma. The present study assessed the genetic association of -174G > C and -572G > C polymorphisms in the IL6 promoter region with primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) in a north Indian Punjabi cohort.

METHODS

910 subjects (313 POAG, 148 PACG cases and 449 controls) were recruited. Genotyping was done by TaqMan assays. Genetic association was tested under different genetic models using Plink. Diplotype and linkage disequilibrium (LD) analysis was done through Haploview. Association of clinical parameters with the genotypes was assessed by one-way ANOVA. Adjustment for potential confounding variables was done by binary logistic regression. IL6 levels were measured in POAG patients and controls.

RESULTS

572G > C variant showed marginal difference in genotype frequency between pooled cases and POAG subgroup with respect to controls (p = 0.042; OR = 1.33; and p = 0.041; OR = 1.37). The GC genotype conferred 1.37-fold protection under codominant model in POAG cases (p = 0.034, OR = 1.37, 95% CI = 1.02-1.85; p_corr = 0.025, OR = 1.45, 95% CI = 1.04-2.02). The mean value for IOP was elevated among cases having 'CC' genotype at the -572G > C locus (p = 0.037). Lower levels of IL6 were detected in POAG patients in plasma samples (p = 0.0001).

CONCLUSION

The study reports suggestive evidence for -572G > C variant in IL6 in affecting genetic susceptibility to POAG in the targeted North Indian Punjabi cohort. A correlation of IL6 levels in aqueous humor (AH) and systemic circulation in POAG was observed, the functional and diagnostic relevance of which may be further investigated.

Meta-analysis: Interleukin 6 gene -174G/C polymorphism associated with type 2 diabetes mellitus and interleukin 6 changes

The gene coding interleukin 6 (IL‐6) is a promising candidate in predisposition to type 2 diabetes mellitus (T2DM). This study aimed to meta‐analytically examine the association of IL‐6 gene −174G/C polymorphism with T2DM and circulating IL‐6 changes across −174G/C genotypes. Odds ratio (OR) and standard mean difference (SMD) with 95% confidence interval (CI) were calculated. Twenty‐five articles were meta‐analysed, with 20 articles for T2DM risk and 9 articles for circulating IL‐6 changes. Overall, there was no detectable significance for the association between −174G/C polymorphism and T2DM, and this association was relatively obvious under dominant model (OR: 0.82, 95% CI: 0.56‐1.21). Improved heterogeneity was seen in some subgroups, with statistical significance found in studies involving subjects of mixed races (OR: 0.63, 95% CI: 0.46‐0.86). Begg's and filled funnel plots, along with Egger's tests revealed week evidence of publication bias. In genotype‐phenotype analyses, carriers of −174CC and −174CG genotypes separately had 0.10 and 0.03 lower concentrations (pg/mL) of circulating IL‐6 than −174GG carriers. Albeit no detectable significance for the association of −174G/C with T2DM, our findings provided suggestive evidence on a dose‐dependent relation between −174G/C mutant alleles and circulating IL‐6 concentrations, indicating possible implication of this polymorphism in the pathogenesis of T2DM.

Association of IL-10 (- 1082 A/G) and IL-6 (- 174 G/C) gene polymorphism with type 2 diabetes mellitus in Ethiopia population

BACKGROUND

Interleukin (IL)-6 and IL-10 are the most important cytokine with pro and anti-inflammatory activities, respectively. Dysregulation of IL-6 and IL-10 are associated with increased risk of developing Type 2 Diabetes Mellitus (T2DM). Despite this, a fundamental understanding of both cytokine gene polymorphisms with its expression is critical in understanding of cellular mechanism of insulin resistance as well as T2DM intervention. Therefore, this study aimed to assess IL-6 (- 174 G/C) and IL-10 (- 1082 A/G) gene polymorphism, and its association with T2DM, North West Ethiopia.

METHODS

A comparative cross-sectional study from January to May 2018 was conducted on study participants with T2DM and apparently healthy controls. Deoxyribonucleic acid (DNA) extraction and genotyping was carried out by using amplification refractory mutation system polymerase chain reaction to detect polymorphism of IL-6 and IL-10 gene at the position - 174 and - 1082, respectively. The logistic regression model was fitted to assess the association of between cytokine gene polymorphisms and T2DM. Odds ratio with 95% CI was determined to assess the presence and strength of association between the explanatory variables and outcome variable. A P-value < 0.05 was considered as statistically significant.

RESULT

Participants carrying the GG genotype of IL-6 (- 174) (OR (95% CI) = 4.61 (2.07-10.54) was a high likelihood of having T2DM compared to those carrying the CC and AA genotypes. AA and AG genotypes of IL-10 (- 1082) were at lower odd of developing T2DM compared to those carrying the GG genotype. In addition, individuals carrying the G allele of IL-6 (- 174) have 2.82-fold odds of developing T2DM compared to individuals carrying the C allele (OR (95% CI) =2.81 (1.78-4.50)).

CONCLUSION

Our study revealed that genetic polymorphisms of IL-6 (- 174) GG genotype is the potential host genetic risk factors to T2DM. While, IL-10 (- 1082) AA genotype is negatively associated with T2DM. Therefore, IL-6 (- 174) and IL-10 (- 1082) genetic variation may be considered as a biomarker for early screening and diagnosis of T2DM.

Pathogenic Pathways and Therapeutic Approaches Targeting Inflammation in Diabetic Nephropathy

Diabetic nephropathy (DN) is associated with an increased morbidity and mortality, resulting in elevated cost for public health systems. DN is the main cause of chronic kidney disease (CKD) and its incidence increases the number of patients that develop the end-stage renal disease (ESRD). There are growing epidemiological and preclinical evidence about the close relationship between inflammatory response and the occurrence and progression of DN. Several anti-inflammatory strategies targeting specific inflammatory mediators (cell adhesion molecules, chemokines and cytokines) and intracellular signaling pathways have shown beneficial effects in experimental models of DN, decreasing proteinuria and renal lesions. A number of inflammatory molecules have been shown useful to identify diabetic patients at high risk of developing renal complications. In this review, we focus on the key role of inflammation in the genesis and progression of DN, with a special interest in effector molecules and activated intracellular pathways leading to renal damage, as well as a comprehensive update of new therapeutic strategies targeting inflammation to prevent and/or retard renal injury.

Interleukin-6-174G/C polymorphism is associated with a decreased risk of type 2 diabetes in patients with chronic hepatitis C virus

BACKGROUND

Chronic hepatitis C (CHC) is associated with type 2 diabetes mellitus. Although the pathogenesis remains to be elucidated, a growing evidence has suggested a role of pro-inflammatory immune response. Increased serum concentrations of Interleukin 6 (IL-6) have been associated with insulin resistance, type 2 diabetes mellitus as well as advanced forms of liver disease in chronic hepatitis C infection.

AIM

To investigate the frequency of IL-6-174G/C (rs1800795) single nucleotide polymorphism (SNP) in CHC patients and in healthy subjects of the same ethnicity. Associations between type 2 diabetes mellitus (dependent variable) and demographic, clinical, nutritional, virological and, IL-6 genotyping data were also investigated in CHC patients.

METHODS

Two hundred and forty-five patients with CHC and 179 healthy control subjects (blood donors) were prospectively included. Type 2 diabetes mellitus was diagnosed according to the criteria of the American Diabetes Association. Clinical, biochemical, histological and radiological methods were used for the diagnosis of the liver disease. IL-6 polymorphism was evaluated by Taqman SNP genotyping assay. The data were analysed by logistic regression models.

RESULTS

Type 2 diabetes mellitus, blood hypertension and liver cirrhosis were observed in 20.8% (51/245), 40.0% (98/245) and 38.4% (94/245) of the patients, respectively. The frequency of the studied IL-6 SNP did not differ between the CHC patients and controls (P = 0.81) and all alleles were in Hardy-Weinberg equilibrium (P = 0.38). In the multivariate analysis, type 2 diabetes mellitus was inversely associated with GC and CC genotypes of IL-6-174 (OR = 0.42; 95%CI = 0.22-0.78; P = 0.006) and positively associated with blood hypertension (OR = 5.56; 95%CI = 2.79-11.09; P < 0.001).

CONCLUSION

This study was the first to show that GC and CC genotypes of IL-6-174 SNP are associated with a decreased risk of type 2 diabetes mellitus in patients chronically infected with hepatitis C virus. The identification of potential inflammatory mediators involved in the crosstalk between hepatitis C virus and the axis pancreas-liver remains important issues that deserve further investigations.

Whether the risk of gestational diabetes mellitus is affected by TNF-α, IL-6, IL-10 or ADIPOQ polymorphisms: a meta-analysis

BACKGROUND

Whether polymorphisms in tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10) or adiponectin (ADIPOQ) influence the risk of gestational diabetes mellitus (GDM) or not remain inconclusive. Therefore, the authors conducted a meta-analysis to robustly assess relationships between polymorphisms in TNF-α, IL-6, IL-10 or ADIPOQ and the risk of GDM by merging the results of eligible publications.

METHODS

A through literature searching in Medline, Embase, Wanfang, VIP and CNKI was conducted by the authors to identify eligible publications, and twenty-two publications were finally found to be eligible for merged quantitative analyses.

RESULTS

The merged quantitative analyses revealed that ADIPOQ + 45T/G (rs2241766) polymorphism was significantly associated with the risk of GDM in overall population (dominant comparison: OR = 0.70, p < 0.001; recessive comparison: OR = 1.95, p < 0.001; over-dominant comparison: OR = 1.18, p = 0.03; allele comparison: OR = 0.71, p < 0.001) and Asians (dominant comparison: OR = 0.70, p < 0.001; recessive comparison: OR = 1.94, p < 0.001; allele comparison: OR = 0.72, p < 0.001). Nevertheless, we did not observe any positive results for TNF-α - 238G/A (rs361525), TNF-α - 308G/A (rs1800629), IL6 - 174G/C (rs1800795), IL-10 - 819C/T (rs1800871), IL-10 - 592C/A (rs1800872), IL-10 - 1082A/G (rs1800896) and ADIPOQ + 276G/T (rs1501299) polymorphisms.

CONCLUSIONS

The present meta-analysis shows that among investigated TNF-α, IL-6, IL-10 or ADIPOQ polymorphisms, only ADIPOQ + 45T/G (rs2241766) polymorphism may affect the risk of GDM.

Could platelet-to-lymphocyte ratio be a predictor for contrast-induced nephropathy in patients with acute coronary syndrome?: A systematic review and meta-analysis

BACKGROUND

Contrast-induced nephropathy (CIN) is acute renal failure observed after administration of iodinated contrast media during angiographic or other medical procedures. In recent years, many studies have focused on biomarkers that recognize CIN and/or predict its development in advance. One of the many biomarkers studied is the platelet-to-lymphocyte ratio (PLR). We performed a systematic review and meta-analysis to evaluate the correlation between PLR level and CIN.

METHODS

Relevant studies were searched in PUBMED, EMBASE, and Web of Science until September 15, 2018. Case-control studies reporting admission PLR levels in CIN and non-CIN group in patients with acute coronary syndrome (ACS) were included. The pooled weighted mean difference (WMD) and 95% confidence intervals (95%CI) were calculated to assess the association between PLR level and CIN using a random-effect model.

RESULTS

Six relevant studies involving a total of 10452 ACS patients (9720 non-CIN controls and 732 CIN patients) met our inclusion criteria. A meta-analysis of 6 case-control studies showed that PLR levels were significantly higher in CIN group than those in non-CIN group (WMD = 33.343, 95%CI = 18.863 to 47.823, P < .001, I = 88.0%).

CONCLUSION

For patients with ACS after contrast administration, our meta-analysis shows that on-admission PLR levels in CIN group are significantly higher than those of non-CIN group. However, large and matched cohort studies are needed to validate these findings and assess whether there is a real connection or just an association.