Insulin resistance in cardiovascular disease, uremia, and peritoneal dialysis

Sex hormone binding globulin (SHBG) serum levels and insulin resistance in men on chronic hemodialysis

BACKGROUND

In males with end stage renal disease biochemical hypogonadism is a frequent finding. Testosterone and sex hormone binding globulin (SHBG) have been associated with insulin resistance, a well-known condition in uremia. The aim of the present study was to investigate in males on chronic hemodialysis the relationship of testosterone and SHBG serum levels with insulin resistance.

METHODS

In a cross-sectional study we enrolled men treated with chronic hemodialysis who did not suffer from an acute illness or other endocrinopathy, as well as primary hypogonadism, and were not hospitalised. Diabetes mellitus, diabetic nephropathy or previous transplantation were not exclusion criteria. As controls we used a community-based group of healthy males matched for age and Body Mass Index (BMI). We assessed the BMI (kg/m2) from body weight and height, the body fat content (%) by bioelectrical impedance and serum testosterone (ng/ml), SHBG (nmol/L) and estradiol (pg/ml) by standard methods. Testosterone < 3.25 ng/ml defined biochemical hypogonadism. In non-diabetic males, we calculated the homeostasis model assessment index (HOMA-R), an estimate of insulin resistance, from serum fasting insulin and glucose.

RESULTS

27 men (age 54.4 ± 19 years) on chronic hemodialysis (treatment duration 29.1 ± 14.4 months) and 51 healthy men (age 47.1 ± 9.6 years) were included. In men on hemodialysis vs. healthy men there were increased serum levels of SHBG (40.9 ± 26.9 vs. 27.6 ± 11.9 nmol/L; p = 0.031) and a significantly enhanced frequency of biochemical hypogonadism (22.2 vs. 3.9%; p = 0.011). In cases without diabetes (n = 22) a significant correlation was observed between the HOMA-R (r = -0.586, p = 0.004) and the fasting insulin levels (r = -0.650, p = 0.001) on the one hand and the serum SHBG levels on the other.

CONCLUSIONS

Our findings confirm enhanced prevalence of biochemical hypogonadism in males on chronic hemodialysis. In non-diabetic cases the serum levels of SHBG correlated with serum insulin and insulin resistance.

Association Between Peritoneal Glucose Absorption, Lipid Metabolism, and Cardiovascular Disease Risk in Nondiabetic Patients on Peritoneal Dialysis

BACKGROUND

Excessive sugar intake increases the energy metabolic burden and the risk of cardiovascular disease (CVD). Patients on peritoneal dialysis absorb much more glucose than the World Health Organization recommends, but the link to CVD is unclear.

OBJECTIVE

To identify the association between peritoneal glucose absorption, lipid metabolism, and CVD.

METHODS

We applied generalized additive mixed effects and mixed effects Cox proportional hazard models to evaluate the impact of peritoneal glucose absorption on lipid profiles and CVD risk. We performed subgroup analyses by using protein intake (normalized protein nitrogen appearance [nPNA] and normalized protein catabolic rate [nPCR] were used to assess protein intake) and high-sensitivity C-reactive protein (hs-CRP).

RESULTS

After multivariable adjustment, peritoneal glucose absorption per 10 g/d increase was associated with an increase in cholesterol of 0.145 (95% confidence interval [CI]: 0.086-0.204) mmol/L. No link with the total risk of CVD was observed; however, protein intake and hs-CRP levels affected the relationship between glucose absorption and CVD risk. Patients with values for nPNA and nPCR <1.0 g/(kg·d) were associated with a lower risk of CVD (hazard ratio [HR] 95% CI: 0.68 (0.46-0.98)) with glucose absorption per 10 g/d increase. While patients with hs-CRP levels ≥3 mg/d or values for nPNA or nPCR ≥1.0 g/(kg·d) were associated with a higher risk of CVD (HR 95% CI: 1.32 (1.07-1.63); 1.31 (1.02-1.68)) for glucose absorption per 10 g/d increase.

CONCLUSIONS

Our study found a positive correlation between peritoneal glucose absorption and lipid profiles. Increased glucose absorption was associated with a lower risk of CVD in lower protein intake patients and a higher risk of CVD in higher hs-CRP or protein intake levels in patients on peritoneal dialysis.

Associations between estimated glucose disposal rate and arterial stiffness and mortality among US adults with non-alcoholic fatty liver disease

Background

The estimated glucose disposal rate (eGDR), an effective indicator of insulin resistance, has been related to acute coronary syndrome, ischemic stroke and heart failure. This study aims to explore the relationship between eGDR and arterial stiffness, all-cause mortality and cardiovascular mortality in patients with non-alcoholic fatty liver disease (NAFLD).

Methods

Participants with NAFLD were chosen from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018. The main outcomes are arterial stiffness (represented by estimated pulse wave velocity, ePWV), all-cause and cardiovascular mortality. Multiple cox regression models, restricted cubic spline, sensitivity analysis and subgroup analysis were carried out to investigate the correlation between the insulin resistance indicators and mortality and arterial stiffness. Furthermore, receiver operating characteristic curves were used to compare the predictive value of the eGDR with the triglyceride-glucose (TyG) index and the homeostasis model assessment of insulin resistance (HOMA-IR) for all-cause and cardiovascular mortality.

Results

In this study, a total of 4,861 participants were included for analysis. After adjusting confounding factors in the multivariate weighted cox regression model, the eGDR was inversely associated with the all-cause mortality (Q4 vs. Q1, HR =0.65 (0.48-0.89, P=0.01) and cardiovascular mortality (Q4 vs. Q1, HR =0.35 (0.19-0.65, P<0.001). Compared with TyG index and HOMA-IR, the eGDR shows excellent predictive value in all-cause mortality (0.588 vs. 0.550 vs. 0.513, P < 0.001) and cardiovascular mortality (0.625 vs. 0.553 vs. 0.537, P < 0.001). In addition, we found a significant negative correlation between eGDR and arterial stiffness (β=-0.13(-0.14-0.11, P< 0.001). However, TyG index and HOMA-IR showed no significant correlation to arterial stiffness.

Conclusions

Low eGDR (an indicator of insulin resistance) levels are related to an increased risk of arterial stiffness and mortality in NAFLD patients in the United States.

Association between the geriatric nutritional risk index and clinical outcomes among peritoneal dialysis patients: A meta-analysis

BACKGROUND

To identify the relationship between the geriatric nutritional risk index (GNRI) and clinical outcomes in patients receiving peritoneal dialysis (PD).

METHODS

The PubMed, EBASE, Web of Science and CNKI databases were searched for available studies up to December 25, 2023. The primary outcome was all-cause mortality, and the secondary outcomes included the incidence of PD dropout, major adverse cardiac and cerebrovascular events (MACCEs), technique failure and peritonitis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were combined to evaluate the predictive value of the GNRI for the occurrence of the above endpoints.

RESULTS

Ten cohort studies with 3897 patients were included. The pooled results demonstrated that a lower GNRI was significantly associated with a greater incidence of all-cause mortality (HR = 0.71, 95% CI: 0.55-0.91; P = .007). In addition, a decreased GNRI predicted the occurrence of dropout from PD (HR = 0.971, 95% CI: 0.945-0.998, P = .034) and MACCE (HR = 0.95, 95% CI: 0.92-0.98, P = .001). However, no significant associations of the GNRI with technique failure (P = .167) or peritonitis (P = .96) were observed.

CONCLUSION

A low GNRI is significantly associated with poor clinical outcomes and might serve as a novel and valuable prognostic indicator among PD patients.

Muscularity and adiposity are differently associated with inflammatory and nutritional biomarkers among patients on hemodialysis and peritoneal dialysis

PURPOSE

Nutritional alterations are prevalent in patients undergoing hemodialysis (HD) and peritoneal dialysis (PD). We aimed at evaluating whether body composition parameters in HD vs PD are differently associated with nutritional and inflammatory biomarkers.

METHODS

Body composition was assessed by bioimpedance analysis. Neutrophil to lymphocyte ratio (NLR), serum albumin and C-reactive protein were used as nutritional and inflammatory biomarkers. Multivariable linear regression analysis was used to determine association(s) of body composition parameters with biomarkers.

RESULTS

We enrolled a total of 108 patients, 58 on HD and 50 on PD. Fat free mass percent was higher in HD patients than PD (p = 0.006) and higher extracellular water (ECW)/intracellular water (ICW) in HD compared to PD patients (p = 0.023), as well as fat mass index was greater in PD than HD (p = 0.004). In HD patients, albumin positively correlated with fat free mass (r = 0.42; p = 0.001) and ICW/h2 (r = 0.31; p = 0.02). In PD, NLR positively correlated with fat mass (r = 0.36; p = 0.01), fat mass index (r = 0.37; p = 0.01) and ECW (r = 0.41; p = 0.005), and negatively correlated with fat free mass percent (r = -0.30; p = 0.04) and ICW percent (r = -0.34; p = 0.02). By linear regression analysis, in HD fat free mass index was associated with albumin and the absence of diabetes. In PD, the association of fat free mass index was present with NLR. Regarding adiposity, in HD we found no association of ECW/ICW with NLR and CRP, whereas in PD the ECW/ICW was associated with NLR.

CONCLUSION

Inflammation drives body composition changes with differences according to the type of dialysis, as expressed by the modulation of some circulating biomarkers.

Association between triglyceride-glucose index and hypertension: a cohort study based on the China Health and Nutrition Survey (2009-2015)

AIM

Insulin resistance (IR) may participate in the pathogenesis of hypertension by mediating low-grade systemic inflammation. The triglycerides-glucose (TyG) index has recently been suggested as a reliable alternative biochemical marker of IR compared with traditional methods. Herein, we speculated TyG index may also be associated with hypertension.

METHODS

Data of adults were extracted from the China Health and Nutrition Survey (CHNS) in 2009-2015 in this retrospective cohort study. The TyG index was calculated using the formula: TyG = Ln [fasting triglycerides (mg/dL) ×fasting glucose (mg/dL)/2]. Associations between TyG index and hypertension were evaluated by univariate and multivariate logistic regression analyses with odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses of age and gender were also performed. In addition, we assessed the interaction effect between TyG index and body mass index (BMI) on hypertension in participants with different age and gender.

RESULTS

Among 3,413 eligible participants, 1,627 (47.67%) developed hypertension. The average TyG index in hypertension group and non-hypertension group was 8.58 and 8.39 respectively. After adjusting for covariates, we found that compared with participants with TyG index ≤ 8.41 (median value), those who had higher TyG index seemed to have higher odds of hypertension [OR = 1.17, 95%CI: (1.01-1.37)]. Similarly, this association was also discovered in participants who aged ≤ 65 years old [OR = 1.19, 95%CI: (1.01-1.39)] or were female [OR = 1.35, 95%CI: (1.10-1.65)]. Additionally, there was a potential additive interaction effect between obesity and TyG index on hypertension.

CONCLUSION

High TyG index was associated with high odds of hypertension in general population in China, but the causal relationship between them needed further exploration.

Advances in secondary prevention mechanisms of macrovascular complications in type 2 diabetes mellitus patients: a comprehensive review

Type 2 diabetes mellitus (T2DM) poses a significant global health burden. This is particularly due to its macrovascular complications, such as coronary artery disease, peripheral vascular disease, and cerebrovascular disease, which have emerged as leading contributors to morbidity and mortality. This review comprehensively explores the pathophysiological mechanisms underlying these complications, protective strategies, and both existing and emerging secondary preventive measures. Furthermore, we delve into the applications of experimental models and methodologies in foundational research while also highlighting current research limitations and future directions. Specifically, we focus on the literature published post-2020 concerning the secondary prevention of macrovascular complications in patients with T2DM by conducting a targeted review of studies supported by robust evidence to offer a holistic perspective.

A landscape of metabolic variation among clinical outcomes of peritoneal dialysis in end-stage renal disease

BACKGROUND

Peritoneal dialysis (PD) helps prevent lethal complications of end-stage renal disease (ESRD). However, the clinical outcomes are affected by PD-related complications. We investigated metabolic biomarkers to estimate the clinical outcomes of PD and identify patients at high risk of downstream complications and recurrent/relapsing infections.

METHODS

Metabolites of normal control and ESRD patient were compared via an untargeted metabolomic analysis. Potential metabolic biomarkers were selected and quantified using a multiple reaction monitoring-based target metabolite detection method. A nomogram was built to predict the clinical outcomes of PD patients using clinical features and potential metabolic biomarkers with the least absolute shrinkage and selection operator Cox regression model.

RESULTS

Twenty-five endogenous metabolites were identified and analyzed. ESRD-poor clinical outcome-related metabolic modules were constructed. Adenine, isoleucine, tyramine, xanthosine, phenylacetyl-L-glutamine, and cholic acid were investigated using the weighted gene correlation network analysis blue module. Potential metabolic biomarkers were differentially expressed between the NC and ESRD groups and the poor and good clinical outcomes of PD groups. A 3-metabolite fingerprint classifier of isoleucine, cholic acid, and adenine was included in a nomogram predicting the clinical outcomes of PD.

CONCLUSION

Metabolic variations can predict the clinical outcomes of PD in ESRD patients.

Mortality of Peritoneal Dialysis versus Hemodialysis in Older Adults: An Updated Systematic Review and Meta-Analysis

INTRODUCTION

The optimal choice of dialysis modality remains contentious in older adults threatened by advanced age and high risk of comorbidities.

METHODS

We conducted a systematic review and meta-analysis of cohort and case-control studies to assess mortality risk between peritoneal dialysis (PD) and hemodialysis (HD) in older adults using PubMed, Embase, and the Cochrane Library database from inception to June 1, 2022. The outcome of interest is all-cause mortality.

RESULTS

Thirty-one eligible studies with >774,000 older patients were included. Pooled analysis showed that PD had a higher mortality rate than HD in older dialysis population (HR 1.17, 95% CI: 1.10-1.25). When stratified by co-variables, our study showed an increased mortality risk of PD versus HD in older patients with diabetes mellitus or comorbidity who underwent longer dialysis duration (more than 3 years) or who started dialysis before 2010. However, definitive conclusions were constrained by significant heterogeneity.

CONCLUSION

From the survival point of view, caution is needed to employ PD for long-term use in older populations with diabetes mellitus or comorbid conditions. However, a tailored treatment choice needs to take account of what matters to older adults at an individual level, especially in the context of limited survival improvements and loss of quality of life. Further research is still awaited to conclude this topic.

The associations of risk of cardiovascular disease with development stages of diabetes in Chinese population: findings from a retrospective cohort study in QuZhou city

BACKGROUND

Risk analysis is an important area of research in diabetes and cardiovascular disease (CVD), both of which have significant global health burdens. Although there is evidence that patients with prediabetes and diabetes mellitus may have an increased risk of CVD, few studies have been conducted in mainland China.

METHODS

This retrospective cohort study utilized data from the Quzhou City Resident Health Information System and the Zhejiang Province Chronic Disease Surveillance System in China. Prediabetes and diabetes mellitus were the exposure interests, and the outcome event was defined as the onset of cardiovascular and cerebrovascular disease (including coronary heart disease and stroke). The start date of the study was January 1, 2015, and the follow-up deadline was December 31, 2020. Multivariate Cox proportional hazard model were used to assess the associations among prediabetes, diabetes, and CVD risk. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. Our study used follow-up time as the time scale, while adjusting for age, sex, physical activity, smoking, alcohol consumption, BMI in the models Sensitivity analyses were conducted to assess the stability of the results, by excluding participants who smoked and drank alcohol, participants who developed CVD in the first year of follow-up.

RESULTS

In total, 138,970 participants were included in our study, with a mean follow-up of 5.8 years. The mean age of the participants was 58.82 ± 14.44 years, with 42.79% (n = 59,466) males and 57.21% (n = 79,504) females. During the study period 4357 cases of CVD were recorded. Participants with prediabetes (P = 0.003) and diabetes (P < 0.001) had a higher risk of CVD than those who were Normal (HR [95% CI]: 1.14 [1.05-1.24]; 1.68 [1.55-1.81], respectively). Prediabetes and patients living with diabetes had a 14% and 68% increased risk of CVD, respectively. The results of the sensitivity analyses were consistent with those of the main analyses after excluding those who developed CVD within one year of follow-up and those who were concurrent smokers or alcohol drinkers.

CONCLUSIONS

Our research found that prediabetes is significantly associated with the risk of diabetes and CVD.

Glycemic control and cardiovascular outcomes in patients with diabetes and coronary artery disease according to triglyceride-glucose index: a large-scale cohort study

BACKGROUND

The role of triglyceride-glucose (TyG) index, an insulin resistance indicator, in glycemic management for diabetic patients with coronary artery disease (CAD) was still unknown. Therefore, we aimed to explore the association between glycemic control and cardiovascular (CV) outcomes in patients with diabetes and CAD according to different TyG index levels.

METHODS

A total of 9996 diabetic patients with angiograph-proven CAD were consecutively recruited from 2017 to 2018 at Fuwai Hospital. Patients were assigned into 3 groups according to TyG index tertiles (T) (T1: <8.895; T2: 8.895-9.400; T3: ≥9.400). According to American Diabetes Association guidelines, controlled glycemia was defined as targeting glycosylated hemoglobin Alc (HbA1c) < 7%. The primary endpoint was CV events including CV death, nonfatal myocardial infarction, and nonfatal stroke.

RESULTS

During a median 3-year follow-up, 381 (3.8%) CV events occurred. Overall, high TyG index (T3) was associated with increased risk of CV events (hazard ratio [HR]: 1.40; 95% confidence interval [CI]: 1.02-1.94) compared with the lowest TyG index (T1) after multivariable adjustment. Upon stratification by the TyG index, in fully adjusted models, controlled glycemia was associated with reduced risk of CV events in the high TyG index (T3) subgroup (HR: 0.64; 95%CI: 0.42-0.96) but not in the low (T1; HR: 0.79; 95%CI: 0.53-1.16) and moderate (T2; HR: 0.84; 95%CI: 0.56-1.25) TyG index subgroups.

CONCLUSIONS

Controlled glycemia was associated with improved CV outcomes in patients with diabetes and established CAD, especially in those with high TyG index levels. Our study, for the first time, provided valuable information that TyG index could help making risk stratification on the glycemic management in diabetic patients with CAD.

The association between insulin resistance and depressive symptoms - A national representative cross-sectional study

OBJECTIVE

Increasing evidence suggests a positive association between insulin resistance (IR) and depression. However, whether sex-or body mass index-specific differences exist remains controversial, and only few studies have analyzed specific symptom domains. Thus, the present study aimed to analyze the association between IR and depressive symptom domains and to clarify the effects of sex and body mass index.

METHODS

The study sample comprised 4007 participants, aged 19-79, from the Korea National Health and Nutrition Examination Study 2020. Participants completed health interviews and examinations, providing data on circulating insulin and glucose levels, the Patient Health Questionnaire-9 (PHQ-9), and related covariates. IR was calculated using the homeostasis model assessment of insulin resistance. Associations between IR and PHQ-9 were analyzed using negative binomial regression with adjustments for the complex survey design.

RESULTS

The association between log-transformed IR and PHQ-9 total scores was statistically significant (incidence rate ratio [IRR] = 1.17, 95% confidence interval [CI] = 1.07-1.29, p = 0.001). Only body mass index specific differences were statistically significant, as the association was only significant in those without obesity (IRR = 1.21, 95% CI = 1.06-1.38, p = 0.005). IR was associated with cognitive/affective (IRR = 1.23, 95% CI = 1.08-1.41, p = 0.002) and somatic (IRR = 1.14, 95% CI = 1.04-1.25, p = 0.005) depressive symptom domains. Sensitivity analyses revealed similar results.

CONCLUSIONS

IR was positively associated with cognitive/affective and somatic depressive symptoms in non-obese individuals.

Triglyceride-glucose index, renal function and cardiovascular disease: a national cohort study

BACKGROUND

The triglyceride-glucose (TyG) index is a predictor of cardiovascular diseases; however, to what extent the TyG index is associated with cardiovascular diseases through renal function is unclear. This study aimed to evaluate the complex association of the TyG index and renal function with cardiovascular diseases using a cohort design.

METHODS

This study included participants from the China Health and Retirement Longitudinal Study (CHARLS) free of cardiovascular diseases at baseline. We performed adjusted regression analyses and mediation analyses using Cox models. The TyG index was calculated as Ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Renal function was defined by the estimated glomerular filtration rate (eGFR).

RESULTS

A total of 6 496 participants were included in this study. The mean age of the participants was 59.6 ± 9.5 years, and 2996 (46.1%) were females. During a maximum follow-up of 7.0 years, 1 996 (30.7%) people developed cardiovascular diseases, including 1 541 (23.7%) cases of heart diseases and 651 (10.0%) cases of stroke. Both the TyG index and eGFR level were significantly associated with cardiovascular diseases. Compared with people with a lower TyG index (median level) and eGFR ≥ 60 ml/minute/1.73 m2, those with a higher TyG index and decreased eGFR had the highest risk of cardiovascular diseases (HR, 1.870; 95% CI 1.131-3.069). Decreased eGFR significantly mediated 29.6% of the associations between the TyG index and cardiovascular diseases.

CONCLUSIONS

The combination of a higher TyG index and lower eGFR level was associated with the highest risk of cardiovascular diseases. Renal function could mediate the association between the TyG index and cardiovascular risk.

Triglyceride-glucose index in the prediction of clinical outcomes after successful recanalization for coronary chronic total occlusions

BACKGROUND

Triglyceride-glucose index (TyG) has been widely used to predict cardiovascular outcomes. However, it remains unclear whether TyG holds prognostic significance for patients with coronary chronic total occlusions (CTO). Thus, our study aimed to evaluate the predictive accuracy and prognostic value of TyG in individuals who underwent successful percutaneous coronary intervention (PCI) for CTO.

METHODS

A total of 331 consecutive patients with ≥ 1 successful CTO-PCI were included. The baseline and angiographic data were acquired. The duration of follow-up ranged from 32 to 79 months, with a median of 44 months and an interquartile range of 39 to 67 months. The primary outcome measured was the occurrence of major adverse cardiac and cerebrovascular events (MACCE), including mortality, target vessel revascularization, recurrent myocardial infarction, and stroke.

RESULTS

After controlling for confounders, multivariate Cox regression analysis revealed that TyG remained statistically significant, regardless of being a continuous or categorical variable. In the partially adjusted regression model, the Hazard ratio (95%CI) for MACCE was 2.54 (1.12-5.79) in tertile 3 and 1.61 (1.22-2.12) per SD increase in the TyG.Kaplan-Meier survival analysis demonstrated significant differences in MACCE-free survival rates across tertiles of the TyG, as indicated by the log-rank test (p = 0.001). ROC analysis was conducted to evaluate the predictive ability of TyG for MACCE, resulting in an AUC of 0.677.

CONCLUSION

The TyG index demonstrates independent predictive capabilities for MACCE in patients who have undergone successful CTO-PCI. These findings suggest that TyG holds the potential as a valuable tool in risk stratification and the identification of patients who may benefit from early intervention in the management of CTO.

Transcriptomic analysis identifies novel candidates in cardiorenal pathology mediated by chronic peritoneal dialysis

Peritoneal dialysis (PD) is associated with increased cardiovascular (CV) risk. Studies of PD-related CV pathology in animal models are lacking despite the clinical importance. Here we introduce the phenotypic evaluation of a rat model of cardiorenal syndrome in response to chronic PD, complemented by a rich transcriptomic dataset detailing chronic PD-induced changes in left ventricle (LV) and kidney tissues. This study aims to determine how PD alters CV parameters and risk factors while identifying pathways for potential therapeutic targets. Sprague Dawley rats underwent Sham or 5/6 nephrectomy (5/6Nx) at 10 weeks of age. Six weeks later an abdominal dialysis catheter was placed in all rats before random assignment to Control or PD (3 daily 1-h exchanges) groups for 8 days. Renal and LV pathology and transcriptomic analysis was performed. The PD regimen reduced circulating levels of BUN in 5/6Nx, indicating dialysis efficacy. PD did not alter blood pressure or cardiovascular function in Sham or 5/6Nx rats, though it attenuated cardiac hypertrophy. Importantly PD increased serum triglycerides in 5/6Nx rats. Furthermore, transcriptomic analysis revealed that PD induced numerous changed transcripts involved with inflammatory pathways, including neutrophil activation and atherosclerosis signaling. We have adapted a uremic rat model of chronic PD. Chronic PD induced transcriptomic changes related to inflammatory signaling that occur independent of 5/6Nx and augmented circulating triglycerides and predicted atherosclerosis signaling in 5/6Nx LV tissues. The changes are indicative of increased CV risk due to PD and highlight several pathways for potential therapeutic targets.

Leucine-973 is a crucial residue differentiating insulin and IGF-1 receptor signaling

Insulin and IGF-1 receptors (IR and IGF1R) are highly homologous and share similar signaling systems, but each has a unique physiological role, with IR primarily regulating metabolic homeostasis and IGF1R regulating mitogenic control and growth. Here, we show that replacement of a single amino acid at position 973, just distal to the NPEY motif in the intracellular juxtamembrane region, from leucine, which is highly conserved in IRs, to phenylalanine, the highly conserved homologous residue in IGF1Rs, resulted in decreased IRS-1/PI3K/Akt/mTORC1 signaling and increased Shc/Gab1/MAPK cell cycle signaling. As a result, cells expressing L973F-IR exhibited decreased insulin-induced glucose uptake, increased cell growth, and impaired receptor internalization. Mice with knockin of the L973F-IR showed similar alterations in signaling in vivo, and this led to decreased insulin sensitivity, a modest increase in growth, and decreased weight gain when mice were challenged with a high-fat diet. Thus, leucine-973 in the juxtamembrane region of the IR acts as a crucial residue differentiating IR signaling from IGF1R signaling.

Triglyceride glucose index predicts all-cause mortality in oldest-old patients with acute coronary syndrome and diabetes mellitus

BACKGROUND

Acute coronary syndrome (ACS) and diabetes mellitus (DM) are the leading health risks for the elderly. Triglyceride-glucose (TyG) index is a novel and reliable indicator of insulin resistance (IR). This study aims to explore the relationship between the TyG index and all-cause mortality in oldest-old patients with ACS and DM.

METHODS

Seven hundred twenty hospitalized patients with ACS aged ≥ 80 years were enrolled, and 699 patients signed informed consent for the study. During the follow-up period, 37 were lost to follow-up, and the follow-up rate was 94.7%. 231 ACS patients with DM were selected for the study's analyses. Kaplan-Meier curve, Cox regression model and receiver operating characteristic (ROC) curve were used to analyze the association between the TyG index and all-cause mortality.

RESULTS

The mean age of participants was 81.58 ± 1.93 years, and 32.47% were women. Compared to TyG tertile 1, the Hazard Ratio (HR) [95% confidence interval (CI)] of all-cause mortality was 2.04 (1.09, 3.81) for TyG tertile 3 in the fully adjusted model. For the TyG index per standard deviation (SD) increment, the HR (95% CI) of all-cause mortality was 1.44 (1.13, 1.83). Further, the association between the TyG index and all-cause mortality was dose-response (P for trend = 0.026). ROC curve analyses indicated that the TyG index outperformed FBG and TG in the prediction of mortality risk and improved the prognostic value of the Gensini score combined with LVEF.

CONCLUSION

The TyG index predicts the risk of all-cause mortality in the oldest-old ACS patients with DM.

Unique ligand and kinase-independent roles of the insulin receptor in regulation of cell cycle, senescence and apoptosis

Insulin acts through the insulin receptor (IR) tyrosine kinase to exert its classical metabolic and mitogenic actions. Here, using receptors with either short or long deletion of the β-subunit or mutation of the kinase active site (K1030R), we have uncovered a second, previously unrecognized IR signaling pathway that is intracellular domain-dependent, but ligand and tyrosine kinase-independent (LYK-I). These LYK-I actions of the IR are linked to changes in phosphorylation of a network of proteins involved in the regulation of extracellular matrix organization, cell cycle, ATM signaling and cellular senescence; and result in upregulation of expression of multiple extracellular matrix-related genes and proteins, down-regulation of immune/interferon-related genes and proteins, and increased sensitivity to apoptosis. Thus, in addition to classical ligand and tyrosine kinase-dependent (LYK-D) signaling, the IR regulates a second, ligand and tyrosine kinase-independent (LYK-I) pathway, which regulates the cellular machinery involved in senescence, matrix interaction and response to extrinsic challenges.

Spiroganodermaines A-G from Ganoderma species and their activities against insulin resistance and renal fibrosis

Ganoderma mushrooms are a renowned Chinese medicine and functional food used worldwide. Seven undescribed spiro Ganoderma meroterpenoids spiroganodermaines A-G were isolated from Ganoderma species. Their structures were characterized by using spectroscopic, computational and X-ray diffraction methods. Biological studies showed that (+)-spiroganodermaine G significantly activates glucose uptake and IRS1 phosphorylation in insulin resistance C2C12 cells. Furthermore, (-)-spiroganodermaine G inhibits the expressions of fibronectin and α-SMA in TGF-β1 induced NRK-52E cells. These findings demonstrate the potential of Ganoderma meroterpenoids as medicines and dietary supplements.

Oxidative stress: An essential factor in the process of arteriovenous fistula failure

For more than half a century, arteriovenous fistula (AVFs) has been recognized as a lifeline for patients requiring hemodialysis (HD). With its higher long-term patency rate and lower probability of complications, AVF is strongly recommended by guidelines in different areas as the first choice for vascular access for HD patients, and its proportion of application is gradually increasing. Despite technological improvements and advances in the standards of postoperative care, many deficiencies are still encountered in the use of AVF related to its high incidence of failure due to unsuccessful maturation to adequately support HD and the development of neointimal hyperplasia (NIH), which narrows the AVF lumen. AVF failure is linked to the activation and migration of vascular cells and the remodeling of the extracellular matrix, where complex interactions between cytokines, adhesion molecules, and inflammatory mediators lead to poor adaptive remodeling. Oxidative stress also plays a vital role in AVF failure, and a growing amount of data suggest a link between AVF failure and oxidative stress. In this review, we summarize the present understanding of the pathophysiology of AVF failure. Furthermore, we focus on the relation between oxidative stress and AVF dysfunction. Finally, we discuss potential therapies for addressing AVF failure based on targeting oxidative stress.

Fibrosis of Peritoneal Membrane as Target of New Therapies in Peritoneal Dialysis

Peritoneal dialysis (PD) is an efficient renal replacement therapy for patients with end-stage renal disease. Even if it ensures an outcome equivalent to hemodialysis and a better quality of life, in the long-term, PD is associated with the development of peritoneal fibrosis and the consequents patient morbidity and PD technique failure. This unfavorable effect is mostly due to the bio-incompatibility of PD solution (mainly based on high glucose concentration). In the present review, we described the mechanisms and the signaling pathway that governs peritoneal fibrosis, epithelial to mesenchymal transition of mesothelial cells, and angiogenesis. Lastly, we summarize the present and future strategies for developing more biocompatible PD solutions.

Association of Atherogenic Index of Plasma With Angiographic Progression in Patients With Suspected Coronary Artery Disease

The present study aimed to explore the correlation of atherogenic index of plasma (AIP) with angiographic progression of coronary artery disease (CAD). AIP was defined as the base 10 logarithm of the ratio of the triglyceride to high-density lipoprotein cholesterol concentration. The extent of coronary lesion was assessed by the Gensini Score (GS) system and angiographic progression was defined as the GS rate of change per year >1 point. A total of 896 patients with suspected CAD who underwent coronary computed tomography angiography twice at intervals of >6 months were included. Baseline AIP was positively correlated with remnant cholesterol (r = .644, P < .001). When patients were assigned into four groups according to baseline AIP quartiles, the incidence of CAD progression significantly increased across the quartiles of AIP (Q1 [lowest]: 23.7 vs Q2: 29.9 vs Q3: 33.9 vs Q4 [highest]: 34.8%; P = .042). After multivariate adjustment, the odds ratio for CAD progression was 1.89 when comparing the highest to the lowest quartile of AIP (95% confidence interval: 1.18-3.02; P = .008). Therefore, AIP was independently correlated with angiographic progression of CAD beyond conventional risk factors, suggesting that AIP may play a role in early risk stratification as a simple surrogate of residual risk.

Evaluation of the long-term prognostic ability of triglyceride-glucose index for elderly acute coronary syndrome patients: a cohort study

Background

With the advancement of the world population aging, more attention should be paid to the prognosis of elderly patients with acute coronary syndrome (ACS). Triglyceride-glucose (TyG) index is a reliable indicator of insulin resistance (IR) and is closely related to traditional risk factors of cardiovascular disease (CVD). However, the effect of TyG index on the prognosis of long-term adverse events in elderly ACS patients has not been reported. This study evaluated the prognostic power of TyG index in predicting adverse events in elderly ACS patients.

Methods

In this study, 662 ACS patients > 80 years old who were hospitalized from January 2006 to December 2012 were enrolled consecutively and the general clinical data and baseline blood biochemical indicators were collected. The follow-up time after discharge was 40–120 months (median, 63 months; interquartile range, 51‒74 months). In addition, the following formula was used to calculate the TyG index: Ln [fasting TG (mg/dL) × FBG (mg/dL)/2], and patients were divided into three groups according to the tertile of the TyG index.

Results

The mean age of the subjects was 81.87 ± 2.14 years, the proportion of females was 28.10%, and the mean TyG index was 8.76 ± 0.72. The TyG index was closely associated with the traditional risk factors of CVD. In the fully-adjusted Cox regression model, the Hazard ratio (95% CI) of all-cause mortality (in tertile 3) was 1.64 (1.06, 2.54) and major adverse cardiac event (MACE) (in tertile 3) was 1.36 (1.05, 1.95) for each SD increase in the TyG index. The subgroup analyses also confirmed the significant association of the TyG index and long-term prognosis.

Conclusion

The TyG index is an independent predictor of long-term all-cause mortality and MACE in elderly ACS patients.

Association between the Triglyceride-Glucose Index and the Risk of Large Artery Atherosclerotic Stroke

The aim of this study is to evaluate the value of the triglyceride-glucose (TyG) index and the risk of large artery atherosclerotic (LAA) stroke. Information on general demographic and clinical characteristics, magnetic resonance angiography (MRA) examination, and blood biochemical index determination were obtained. Based on age stratification, three models to evaluate the odds ratio (OR) and the 95% confidence interval (95% CI) were employed to determine the correlation between the TyG index and the risk of LAA stroke. The most effective TyG index threshold in predicting a high risk of LAA stroke was identified using receiver operating characteristic (ROC) curve analysis. Logistic regression verified the association between the risk of LAA stroke and the TyG index. Both with and without age stratification, logistic regression analysis showed that the TyG index was a significant predictor of the occurrence of LAA stroke (P < 0.05). The maximum Youden index for determining a high risk of LAA stroke was found at a TyG index of 4.60. The area under the ROC curve was 0.69 (95% CI: 0.646-0.742, P < 0.05), sensitivity was 78.0%, and specificity was 63.4%. An elevated TyG index was remarkably associated with a high risk of LAA stroke.