Insulin Resistance Is Associated with Interleukin 1β (IL-1β) in Non-Diabetic Hemodialysis Patients

Effect of limb ischemic preconditioning on the indirect index of insulin resistance in maintenance hemodialysis patients

BACKGROUND

Poor prognosis of maintenance hemodialysis (MHD) patients, including cardiovascular disease (CVD) and protein-energy wasting (PEW), is strongly associated with insulin resistance (IR). Previous studies have revealed that limb ischemic preconditioning (LIPC), as an intervention, is effective in reducing inflammation and oxidative stress levels in patients. The aim of this study was to elucidate the effects of LIPC on IR indirect indices, inflammation and oxidative stress indices, and to further explore the potential mechanisms of LIPC in reducing IR indices.

METHODS

A retrospective analysis was performed on 62 patients with MHD who had previously undergone limb ischemia preconditioning (LIPC) or sham surgery (Sham). General clinical and laboratory data were collected. Furthermore, to assess the IR status of MHD patients, the following indices were employed: triglyceride-glucose index (TyG), triglyceride-glucose body mass index (TyG-BMI), triglyceride-to-high-density lipoprotein cholesterol ratio (TG/HDL-C), and metabolic score of insulin resistance (METS-IR). Inflammation and oxidative stress indicators included high-sensitivity C-reactive protein (hs-CRP), hs-CRP /albumin ratio (CAR), serum malondialdehyde (MDA) and superoxide dismutase (SOD). Mediation analysis was conducted using Model 4 in the SPSS PROCESS macro version 4.1.

RESULTS

Following a four-week experiment, hs-CRP (15.46 ± 3.60 vs. 10.53 ± 5.42, p < 0.001), CAR (0.39 ± 0.10 vs. 0.26 ± 0.13, p < 0.001) and MDA (8.46(6.71,9.85) vs. 5.99(5.11,7.89), p = 0.001) indices were significantly decreased in the MHD patients of the LIPC group, whereas SOD indices (215.07(180.27,286.45) vs. 267.76(228.32,319.54), p = 0.012) were significantly higher. Only hs-CRP (-4.93 ± 5.68 vs. 0.16 ± 5.39, p = 0.001) and CAR (-0.14 ± 0.14 vs. -0.001 ± 0.15, p = 0.001) were significantly different in the LIPC group compared to the Sham group. In contrast, the changes in MDA (p = 0.058) and SOD (p = 0.107) were not statistically significant between groups. The intra- and inter-group differences in the four indirect indices of IR were significant (p < 0.05). The heatmap revealed a notable correlation between the changes in hs-CRP and CAR levels and the changes in the IR indirect indices. In addition, The mediation model showed that the inflammatory indicators hs-CRP played a partial mediating role in the improvement of IR indices (TyG-BMI) by LIPC.

CONCLUSION

LIPC has an excellent ability to inhibit inflammation and peroxidation. In addition, in MHD patients, inflammation plays a significant role in the process of LIPC improving IR index.

Association of the interaction between interleukin-1β gene polymorphism and smoking status with the diabetic nephropathy risk in a Chinese Han population

OBJECTIVES

we aimed to evaluate the association of interleukin-1β (IL-1β) gene single nucleotide polymorphisms (SNPs) and its interaction with smoking status on diabetic nephropathy (DN) risk in a Chinese Han population.

METHODS

The Hardy-Weinberg equilibrium (HWE) was tested by using SNPStats ( https://www.snpstats.net/start.htm ), which was also used for testing the relationship between four SNPs and DN risk and haplotype analysis. The SNP- SNP and gene- smoking interaction were verified by using generalized multifactor dimensionality reduction (GMDR) model.

RESULTS

Logistic regression suggested that the DN risks of participants with rs16944- G allele were significantly higher than those with AA genotype, adjusted OR (95%CI) = 1.62 (1.24-2.01) for AG versus AA, 1.41 (0.75-2.12) for GG versus AA. Additionally, we also found that participants with rs3917356- T allele had an obviously higher DN risk than those with CC genotype, adjusted OR (95%CI) = 1.75 (1.34-2.19) for CT versus CC, 1.87 (1.23-2.54) for TT versus CC. GMDR model found a significant two-locus model (P = 0.011) including rs16944 and smoking. Compared with non- smokers with rs16944- AA genotype, smokers with rs1225404 AG or GG genotype had the highest DN risk after covariates adjustment, OR (95%CI) was 3.04 (1.98-4.12). We also found a haplotype containing rs1143634- T and rs3917356- T was associated with higher DN risk.

CONCLUSIONS

we found that the rs16944- G and rs3917356- T allele, interaction between rs16944 and smoking, haplotype containing rs1143634- T and rs3917356- T were all associated with increased DN risk.

Prognostic value of atherogenic index of plasma in pulmonary hypertension

Background

The atherogenic index of plasma (AIP) is a brand-new lipid parameter that has been used to assess various cardiovascular events. This study aimed to investigate the prognostic value of AIP in patients with pulmonary hypertension (PH).

Methods

This retrospective study was conducted at Shanghai Jiao Tong University School of Medicine affiliated Renji Hospital, and included data from 125 PH patients treated during 2014-2018. The endpoint events of this study were clinical worsening outcomes. PH patients include those from group 1 and group 4. AIP was determined as the logarithm of the blood triglycerides ratio to high-density lipoprotein cholesterol.

Results

The 1-year, 3-year, and 5-year incidence rates of clinical worsening outcomes in PH patients in this study were 20.0, 44.8, and 54.4%, respectively. The median age of the PH patients was 38.00 years, with females accounting for 90.4%. After controlling for multivariable factors, the results of Cox regression analysis indicated that AIP was an independent predictor of adverse outcomes with a hazard ratio and 95% confident interval (CI) of 2.426 (1.021-5.763). The positive linear relationship of AIP was evaluated using restricted cubic spline analysis. Kaplan-Meier curves showed a significantly higher events rate in patients with AIP ≥ 0.144 compared to those with AIP < 0.144 (p = 0.002). Four potential prognostic variables, including AIP, were identified by LASSO regression to construct a nomogram. Compared to the model minus AIP, the AUC of the nomogram displayed a non-significant improvement (0.749 vs. 0.788, p = 0.298). In contrast, the results of net reclassification improvement (0.306, 95% CI: 0.039-0.459, p < 0.001) and integrated discrimination improvement (0.049, 95% CI: 0.006-0.097, p = 0.020) demonstrated significant enhancements in the predictive ability of the model when AIP was added to the clinical model.

Conclusion

AIP is an independent predictor of long-term clinical worsening in PH patients, and its inclusion in prognostic models could improve risk stratification and management.

Mitochondrial Methionyl-tRNA Formyltransferase Deficiency Alleviates Metaflammation by Modulating Mitochondrial Activity in Mice

Various studies have revealed the association of metabolic diseases with inflammation. Mitochondria are key organelles involved in metabolic regulation and important drivers of inflammation. However, it is uncertain whether the inhibition of mitochondrial protein translation results in the development of metabolic diseases, such that the metabolic benefits related to the inhibition of mitochondrial activity remain unclear. Mitochondrial methionyl-tRNA formyltransferase (Mtfmt) functions in the early stages of mitochondrial translation. In this study, we reveal that feeding with a high-fat diet led to the upregulation of Mtfmt in the livers of mice and that a negative correlation existed between hepatic Mtfmt gene expression and fasting blood glucose levels. A knockout mouse model of Mtfmt was generated to explore its possible role in metabolic diseases and its underlying molecular mechanisms. Homozygous knockout mice experienced embryonic lethality, but heterozygous knockout mice showed a global reduction in Mtfmt expression and activity. Moreover, heterozygous mice showed increased glucose tolerance and reduced inflammation, which effects were induced by the high-fat diet. The cellular assays showed that Mtfmt deficiency reduced mitochondrial activity and the production of mitochondrial reactive oxygen species and blunted nuclear factor-κB activation, which, in turn, downregulated inflammation in macrophages. The results of this study indicate that targeting Mtfmt-mediated mitochondrial protein translation to regulate inflammation might provide a potential therapeutic strategy for metabolic diseases.

Prevalence of carbohydrate metabolism disorders in patients with end-stage renal disease on hemodialysis therapy

There are quite a lot of scientific works today dedicated to the role of disorders carbohydrate metabolism (DCM) in the development of end-stage renal disease (ESRD), at the same time, the influence of chronic kidney disease (CKD) on the development of carbohydrate disorders remains insufficiently studied, especially in patients on renal replacement therapy (RRT). The annual steady increase in the number of patients with ESRD without diabetes mellitus (DM) requiring dialysis therapy leads to increased interest and the need to study carbohydrate status in these patients. It is known that hyperglycemia in patients without DM on hemodialysis (HD) is a predisposing factor to the development of cardiovascular accidents that worsen the quality of life and also increase mortality. The peculiarities of glucose metabolism in patients receiving RRT do not always allow adequate assessment of carbohydrate status using glycated hemoglobin (HbA1c). The review provides up-to-date information on the prevalence of DCM in patients with ESRD without DM receiving HD RRT, touches upon the peculiarities of glucose metabolism, interpretation of HbA1c and glycated albumin values, and mortality risk in hemodialysis patients with various DCM.

Prognostic Significance of Abnormal Ankle-Brachial Index Among Long-term Hemodialysis Patients in Kinshasa, the Democratic Republic of the Congo

OBJECTIVE

Early identification of atherosclerosis using a non-invasive tool like ankle-brachial index (ABI) could help reduce the risk for cardiovascular disease among long-term hemodialysis patients. The study objective was to assess the frequency and impact of abnormal ABI as a marker of subclinical peripheral artery disease (PAD) in chronic hemodialysis patients.

METHODS

This was a historic cohort study of kidney failure patients on long-term hemodialysis for at least 6 months. The ABI, measured with two oscillometric blood pressure devices simultaneously, was used to assess subclinical atherosclerosis of low limb extremities. Abnormal ABI was defined as ABI <0.9 or >1.3 (PAD present). Survival was defined as time to death. Independent factors associated with abnormal ABI were assessed using multiple logistic regression analysis. Kaplan-Meier method (log-rank test) was used to compare cumulative survival between the two groups; a P value <0.05 was statistically significant.

RESULTS

Abnormal ABI was noted in 50.6% (n=43) of the 85 kidney failure patients included in the study; 42.4% (n=36) had a low ABI, and 8.2% (n=7) had a high ABI. Factors associated with PAD present were cholesterol (adjusted odds ratio [AOR], 1.02; 95% confidence interval [CI], 1.01-1.04; P=0.019), inflammation (AOR, 9.44; 95% CI, 2.30-18.77; P=0.002), phosphocalcic product (AOR, 6.25; 95% CI, 1.19-12.87; P=0.031), and cardiac arrhythmias (AOR, 3.78; 95% CI, 1.55-7.81, P=0.009). Cumulative survival was worse among patients with PAD present (log-rank; P=0.032).

CONCLUSION

The presence of PAD was a common finding in the present study, and associated with both traditional and emerging cardiovascular risk factors as well as a worse survival rate than patients without PAD.

High n-3 fatty acids counteract hyperglycemia-induced insulin resistance in fat-1 mice via pre-adipocyte NLRP3 inflammasome inhibition

Although n-3 polyunsaturated fatty acids (n-3 PUFAs) have potential anti-insulin resistance activity, the mechanism remains largely unknown. In this study, increased glucose resistance, insulin sensitivity, and lower glycemia were observed upon streptozotocin (STZ) treatment in n-3 PUFA-enriched fat-1 mice compared to wild type (WT) mice. Endogenous n-3 PUFAs in fat-1 mice were found to impair hyperglycemia or high glucose level-induced nucleotide-binding domain and leucine-rich repeat pyrin 3 domain (NLRP3) inflammasome activation and inhibit IL-1β secretion in adipose tissues. In addition, endogenous n-3 PUFAs also inhibited high glucose-induced caspase-1 activity and IL-1β secretion in pre-adipocyte-enriched stromal vascular fractions (SVF) isolated from adipose tissues. Furthermore, in 3T3-L1 pre-adipocytes, high levels of glucose induced thioredoxin interacting protein (TXNIP) expression and activated the NLRP3 inflammasome, which was counteracted by docosahexaenoic acid (DHA), the major n-3 PUFA in fat-1 mice, by downregulating TXNIP via the phosphatidylinositol-3-kinase (PI3K)/Akt pathway. Our results suggest that n-3 PUFA-mediated insulin sensitivity is at least partly associated with inflammasome inhibition in pre-adipocytes. Our findings highlight the potential clinical use of dietary n-3 PUFAs in the prevention or intervention of T2D and other NLRP3 inflammasome-driven inflammatory diseases.

Recent insights on modulation of inflammasomes by adipokines: a critical event for the pathogenesis of obesity and metabolism-associated diseases

Aberrant production of adipokines, a group of adipocytes-derived hormones, is considered one of the most important pathological characteristics of obesity. In individuals with obesity, beneficial adipokines, such as adiponectin are downregulated, whereas leptin and other pro-inflammatory adipokines are highly upregulated. Hence, the imbalance in levels of these adipokines is thought to promote the development of obesity-linked complications. However, the mechanisms by which adipokines contribute to the pathogenesis of various diseases have not been clearly understood. Inflammasomes represent key signaling platform that triggers the inflammatory and immune responses through the processing of the interleukin family of pro-inflammatory cytokines in a caspase-1-dependent manner. Beyond their traditional function as a component of the innate immune system, inflammasomes have been recently integrated into the pathological process of multiple metabolism- and obesity-related disorders such as cardiovascular diseases, diabetes, fatty liver disease, and cancer. Interestingly, emerging evidence also highlights the role of adipokines in the modulation of inflammasomes activation, making it a promising mechanism underlying distinct biological actions of adipokines in diseases driven by inflammation and metabolic disorders. In this review, we summarize the effects of adipokines, in particular adiponectin, leptin, visfatin and apelin, on inflammasomes activation and their implications in the pathophysiology of obesity-linked complications.

Triglyceride-to-High-Density Lipoprotein Cholesterol Ratio and Systemic Inflammation in Patients with Idiopathic Pulmonary Arterial Hypertension

Background

Idiopathic pulmonary arterial hypertension (IPAH) patients are characterized by elevated triglyceride (TG)-to-HDL cholesterol (HDL-C) ratio, which has been proposed to be an important prognostic factor in this population. The mechanism of this phenomenon remains unknown. We therefore investigated the potential determinants of increased TG/HDL-C ratio in IPAH patients.

Material/Methods

We prospectively recruited consecutive clinically stable IPAH patients between January 2016 and February 2017. Patients with diabetes or using statins were excluded. Anthropometric measurements included body mass index (BMI) and skinfold thickness; body fat mass was calculated using age and sex-specific equations. We assessed lipid profile, homeostatic model assessment of insulin resistance (HOMA-IR), serum adipokine levels (adiponectin, resistin, leptin, and visfatin), and circulating cytokines (IL-1β, IL-6, MCP-1, and TNF-α).

Results

We assessed 47 IPAH patients: 9 of them had been diagnosed with diabetes and 10 were treated with statins; therefore, were excluded them from further analysis. Age, sex distribution, and BMI were similar irrespectively of TG/HDL-C ratio. Patients with increased TG/HDL-C ratio (>3) as compared to patients with TG/HDL-C ≤3 were characterized by higher levels of IL-1β, MCP-1, and IL-6. TG level was correlated with IL-1β (R=0.76, p<0.001), IL-6 (R=0.52, p=0.005), TNF-α (R=0.62, p<0.001), and MCP-1 (R=0.63, p<0.001). IL-1β was also inversely correlated with HDL-C (R=−0.44, p=0.02). We found no differences in concentration of fasting glucose, insulin, HOMA-IR, body fat content, or adipokine levels between patients with higher and lower TG/HDL-C ratios.

Conclusions

In IPAH patients, elevated TG/HDL-C ratio is a marker of systemic inflammation.

Influence of colonic dialysis using Gubenxiezhuo on the distribution of gut microflora in uremia rats

OBJECTIVE

This study aimed to explore the underlying function of Gubenxiezhuo dialysis on the distribution of gut microflora uremia.

METHODS

A uremia rat model was constructed, and the morphology of renal tissue was determined using the hematoxylin-eosin (H&E) staining. Moreover, the blood samples were collected and the expression of IL-1β, IL-6, and CRP was determined using enzyme-linked immunosorbent assay. Following these experiments, the gut tissues of rats were collected and the distribution of gut microbiota was explored using real-time PCR.

RESULTS

Compared with the control group, inflammatory infiltration, apoptosis, and bleeding were significantly upregulated in kidney of uremia rats, and Gubenxiezhuo dialysis could obviously ameliorate these changes. Expression of IL-1β, IL-6, and CRP were significantly elevated in uremic rats and Gubenxiezhuo could significantly attenuate these elevations (p < 0.01). In addition, Gubenxiezhuo dialysis also could attenuate the upregulations of Acinetobacter, Bacillus cereus, Proteus vulgaris, Shigella flexneri, and Escherichia coli , and the downregulation of Bifidobacterium, Lactobacillus, and Helicobacter in the uremia rats ( p < 0.05).

CONCLUSION

Gubenxiezhuo dialysis could significantly ameliorate the inflammatory to modulate the distribution of gut microbiota in uremia.

Anxa2 gene silencing attenuates obesity-induced insulin resistance by suppressing the NF-κB signaling pathway

Insulin resistance (IR) continues to pose a major threat to public health due to its role in the pathogenesis of metabolic syndrome and its ever-increasing prevalence on a global scale. The aim of the current study was to investigate the efficacy of Anxa2 in obesity-induced IR through the mediation of the NF-κB signaling pathway. Microarray analysis was performed to screen differentially expressed genes associated with obesity. To verify whether Anxa2 was differentially expressed in IR triggered by obesity, IR mouse models were established in connection with a high-fat diet (HFD). In the mouse IR model, the role of differentially expressed Anxa2 in glycometabolism and IR was subsequently detected. To investigate the effect of Anxa2 on IR and its correlation with inflammation, a palmitic acid (PA)-induced IR cell model was established, with the relationship between Anxa2 and the NF-κB signaling pathway investigated accordingly. Anxa2 was determined to be highly expressed in IR. Silencing Anxa2 was shown to inhibit IR triggered by obesity. When Anxa2 was knocked down, elevated expression of phosphorylated insulin receptor substrate 1 (IRS1), IRS1 and peroxisome proliferator-activated receptor coactivator-1a, and glucose tolerance and insulin sensitivity along with 2-deoxy-d-glucose uptake was detected, whereas decreased expression of suppressor of cytokine signaling 3, IL-6, IL-1β, TNF-α, and p50 was observed. Taken together, the current study ultimately demonstrated that Anxa2 may be a novel drug strategy for IR disruption, indicating that Anxa2 gene silencing is capable of alleviating PA or HFD-induced IR and inflammation through its negative regulatory role in the process of p50 nuclear translocation of the NF-κB signaling pathway.