Insulin resistance and hyperglycaemia in cardiovascular disease development

Identification of candidate metabolite biomarkers for metabolic syndrome and its five components in population-based human cohorts

BACKGROUND

Metabolic Syndrome (MetS) is characterized by risk factors such as abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), hypertension, and hyperglycemia, which contribute to the development of cardiovascular disease and type 2 diabetes. Here, we aim to identify candidate metabolite biomarkers of MetS and its associated risk factors to better understand the complex interplay of underlying signaling pathways.

METHODS

We quantified serum samples of the KORA F4 study participants (N = 2815) and analyzed 121 metabolites. Multiple regression models adjusted for clinical and lifestyle covariates were used to identify metabolites that were Bonferroni significantly associated with MetS. These findings were replicated in the SHIP-TREND-0 study (N = 988) and further analyzed for the association of replicated metabolites with the five components of MetS. Database-driven networks of the identified metabolites and their interacting enzymes were also constructed.

RESULTS

We identified and replicated 56 MetS-specific metabolites: 13 were positively associated (e.g., Val, Leu/Ile, Phe, and Tyr), and 43 were negatively associated (e.g., Gly, Ser, and 40 lipids). Moreover, the majority (89%) and minority (23%) of MetS-specific metabolites were associated with low HDL-C and hypertension, respectively. One lipid, lysoPC a C18:2, was negatively associated with MetS and all of its five components, indicating that individuals with MetS and each of the risk factors had lower concentrations of lysoPC a C18:2 compared to corresponding controls. Our metabolic networks elucidated these observations by revealing impaired catabolism of branched-chain and aromatic amino acids, as well as accelerated Gly catabolism.

CONCLUSION

Our identified candidate metabolite biomarkers are associated with the pathophysiology of MetS and its risk factors. They could facilitate the development of therapeutic strategies to prevent type 2 diabetes and cardiovascular disease. For instance, elevated levels of lysoPC a C18:2 may protect MetS and its five risk components. More in-depth studies are necessary to determine the mechanism of key metabolites in the MetS pathophysiology.

Sex difference in the association of the triglyceride glucose index with obstructive coronary artery disease

Insulin resistance (IR) is associated with cardiovascular disease in non-diabetic patients. The triglyceride-glucose (TyG) index, incorporating serum glucose and insulin concentrations, is a surrogate insulin resistance marker. We investigated its association with obstructive coronary artery disease (CAD) and sex differences therein. Patients with stable angina pectoris requiring invasive coronary angiography between January 2010 and December 2018 were enrolled. They were divided into two groups according to TyG index. Two interventional cardiologists diagnosed obstructive CAD by angiography review. Demographic characteristics and clinical outcomes were compared between groups. Relative to lower index, patients with higher (≥ 8.60) TyG index had higher BMIs and more prevalent hypertension, diabetes, and elevated lipid profiles [total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), fasting plasma glucose (FPG)]. Higher TyG index increased women's obstructive CAD risk after multivariate adjustment (adjusted odds ratio (aOR) 2.15, 95% confidence interval (95% CI) 1.08-4.26, p = 0.02) in non-diabetic populations compared with men. No sex difference was found for diabetic patients. Higher TyG index significantly increased the obstructive CAD risk, overall and for non-diabetic women. Larger-scale studies are needed to confirm our findings.

Association of triglyceride-glucose index with myocardial injury post-stroke in older patients with first-ever ischemic stroke

BACKGROUND

Myocardial injury post-stroke is a common sequela of acute stroke. Triglyceride-glucose index (TyG index), a valuable surrogate indicator of insulin resistance, has been suggested to be closely related to cardiovascular outcomes. However, it is unknown whether the TyG index is independently associated with a higher risk of myocardial injury post-stroke. We therefore investigated the longitudinal association between TyG index and risk of myocardial injury post-stroke in older patients with first-ever ischemic stroke and no prior cardiovascular comorbidities.

METHODS

We included older patients with first-ever ischemic stroke and no prior cardiovascular comorbidities between January 2021 to December 2021. The individuals were stratified into low and high TyG index groups according to the optimal cutoff value with TyG index. We performed logistic regression analysis, propensity score matching (PSM) analysis, restricted cubic spline analysis, and subgroup analyses to explore the longitudinal association between TyG index and risk of myocardial injury post-stroke.

RESULTS

We included 386 individuals with a median age of 69.8 years (interquartile range: 66.6, 75.3). The optimal TyG index cut-off for predicting myocardial injury post-stroke was 8.9 (sensitivity 67.8%; specificity 75.5%; area under curve 0.701). Multivariate logistic regression analysis revealed that the risk of genesis of myocardial injury post-stroke increased with elevated TyG index (odds ratio [OR], 2.333; 95% confidence interval [CI], 1.201-4.585; P = 0.013). Furthermore, all covariates were well balanced between the two groups. The longitudinal association between TyG index and myocardial injury post-stroke remained significantly robust (OR: 2.196; 95% CI: 1.416-3.478; P < 0.001) after PSM adjustment.

CONCLUSION

Individuals with an elevated TyG index were more susceptible to having an increased risk of myocardial injury post-stroke. TyG index thus might be served as a complementary approach for optimized-for-risk stratification in older patients with first-ever ischemic stroke and no prior cardiovascular comorbidities.

Association between triglyceride-glucose index trajectories and carotid atherosclerosis progression

BACKGROUND

The triglyceride-glucose (TyG) index has been recognized as being an alternative cardiometabolic biomarker for insulin resistance associated with the development and prognosis of cardiovascular disease (CVD). However, the prospective relationship between baseline and long-term trajectories of the TyG index and carotid atherosclerosis (CAS) progression has yet to be investigated.

METHODS

This longitudinal prospective cohort study included 10,380 adults with multiple general health checks at Peking University Third Hospital from January 2011 to December 2020. The TyG index was calculated as ln (fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2). The latent class trajectory modeling method was used to analyze the TyG index trajectories over the follow-up. Based on univariate and multivariate Cox proportional hazards analyses, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for the baseline and trajectory of the TyG index.

RESULTS

During a median follow-up period of 757 days, 1813 participants developed CAS progression. Each 1-standard deviation (SD) increase in the TyG index was associated with a 7% higher risk of CAS progression after adjusting for traditional CVD risk factors (HR = 1.067, 95% CI 1.006-1.132). Similar results were observed when the TyG index was expressed as quartiles. According to different trajectory patterns, participants were categorized into low-stable, moderate-stable, and high-increasing groups. After multivariate adjustment, the moderate-stable group had a 1.139-fold (95% CI 1.021-1.272) risk of CAS progression. The high-increasing trajectory of the TyG index tended to be associated with CAS progression (HR = 1.206, 95% CI 0.961-1.513).

CONCLUSIONS

Participants with higher baseline and moderate-stable trajectory of the TyG index were associated with CAS progression. Long-term trajectories of the TyG index can help to identify individuals at a higher risk of CAS progression who deserve specific preventive and therapeutic approaches.

New index using triglyceride glucose-body mass index for predicting mortality in patients with antineutrophil cytoplasmic antibody-associated vasculitis

Background

This study aimed to investigate whether triglyceride glucose-body mass index (TyG-BMI) and a new index using TyG-BMI (NITGB) could predict all-cause mortality in non-obese patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Methods

The medical records of 78 non-obese AAV patients (BMI < 23.0 kg/m² for Asians) were retrospectively reviewed. TyG-BMI was calculated by the equation: Ln (triglyceride × fasting glucose/2) × BMI. To develop NITGB, we assigned a weight of a number close to an 0.1 decimal integer to each variable according to the slopes for independent variables with P-value < 0.1 in the multivariable Cox analysis.

Results

The median age was 54.3 years and five patients died. When non-obese AAV patients were divided into two groups based on TyG-BMI ≥ 187.74, those with TyG-BMI ≥ 187.74 exhibited a significantly higher risk for all-cause mortality than those without (RR 9.450). Since age (HR 1.324), Birmingham vasculitis activity score (BVAS; HR 1.212), and TyG-BMI ≥ 187.74 (HR 12.168) were independently associated with all-cause mortality, NITGB was developed as follows: age + 0.2 × BVAS + 2.5 × TyG-BMI ≥ 187.74. When non-obese AAV patients were divided into two groups based on NITGB ≥ 27.36, those with NITGB ≥ 27.36 showed a significantly higher risk for all-cause mortality than those without (RR 284.000). Both non-obese AAV patients with TyG-BMI ≥ 187.74 and those with NITGB ≥ 27.36 exhibited significantly higher cumulative rates of all-cause mortality than those without.

Conclusion

NITGB along with TyG-BMI could predict all-cause mortality in non-obese AAV patients.

Association of the triglyceride-glucose index with subclinical left ventricular dysfunction in type 2 diabetes mellitus patients: A retrospective cross-sectional study

AIMS/INTRODUCTION

The triglyceride-glucose (TyG) index is a simple and reliable indicator of insulin resistance, and is associated with the development and poor outcomes of cardiovascular disease. Subclinical left ventricular dysfunction (SLVD) is frequently detected in approximately one-third of diabetes patients, but it has not been established whether the TyG index correlates with SLVD. We carried out this research to evaluate the relationship between the TyG index and SLVD in type 2 diabetes mellitus patients.

MATERIALS AND METHODS

This was a cross-sectional and observational study of 183 type 2 diabetes mellitus inpatients at Nanjing Drum Tower Hospital, Nanjing, China. The TyG index and homeostasis model assessment 2 estimates for insulin resistance (HOMA2-IR) were calculated from biochemical measurements, and speckle-tracking echocardiography was carried out. According to global longitudinal strain (GLS) by echocardiography, participants were categorized into the SLVD (GLS <18%) group or the non-SLVD (GLS ≥18%) group.

RESULTS

In comparison with non-SLVD participants, SLVD participants had higher insulin resistance, as reflected by elevated TyG and HOMA2-IR indices, as well as a higher body mass index, waist circumference and triglyceride level (P < 0.05 for each). When grouped by TyG index tertiles, an elevated TyG index was correlated with other cardiometabolic risk factors, as well as a decrease in GLS. In the multivariate logistic regression analyses, the TyG index was an independent risk factor for SLVD in type 2 diabetes mellitus patients (odds ratio 2.047, 95% confidence interval 1.07-3.914, P  = 0.03), whereas HOMA2-IR was not.

CONCLUSIONS

The TyG index is independently associated with SLVD in type 2 diabetes mellitus patients and is a more reliable indicator of SLVD than HOMA2-IR.

Dietary patterns explaining variations in blood biomarkers in young adults are associated with the 30-year predicted cardiovascular disease risks in midlife: A follow-up study

BACKGROUND AND AIMS

To examine a combined effect of dietary intakes, blood lipid and insulin resistance in young adulthood on the risk of predicted CVD through midlife.

METHODS AND RESULTS

Data of young adults from a birth cohort study in Australia were used. Reduced rank regression (RRR) and partial least squares (PLS) methods identified dietary patterns rich in meats, refined grains, processed and fried foods, and high-fat dairy and low in whole grains and low-fat dairy from dietary intakes obtained at 21-years, and blood lipids and measures of insulin resistance measured at 30-years of age. Using standard CVD risk factors measured at 30-years of age, the Framingham Heart Study risk-prediction algorithms were used to calculate the 30-year predicted Framingham CVD risk scores. The scores represent Hard CVD events; coronary death, myocardial infarction and stroke and Full CVD events; Hard CVD plus coronary insufficiency and angina pectoris, transient ischaemic attack, intermittent claudication, and congestive heart failure in midlife. Sex-specific upper quartiles of CVD risk scores were used to define high-risk groups. Modified Poisson regression models were used to estimate relative risks (RRs) with 95% CI. Greater adherence to the diet identified applying RRR in young adulthood was associated with higher risks of predicted Hard CVD (RR: 1.60; 1.14, 2.25) and Full CVD (RR: 1.46; 1.04, 2.05) events in midlife. The diet from PLS showed similar trend of association for the risk of predicted Hard CVD events (RR: 1.49; 1.03, 2.16) in adjusted models.

CONCLUSION

Dietary patterns associated with variations in blood lipids and insulin resistance in young adulthood are associated with increased risks of predicted CVD events in midlife. The findings suggest that diet induced altered blood lipids and insulin resistance in the life course of young adulthood could increase the risks of CVD events in later life.

Neutrophil (dys)function due to altered immuno-metabolic axis in type 2 diabetes: implications in combating infections

Metabolic and inflammatory pathways are highly interdependent, and both systems are dysregulated in Type 2 diabetes (T2D). T2D is associated with pre-activated inflammatory signaling networks, aberrant cytokine production and increased acute phase reactants which leads to a pro-inflammatory 'feed forward loop'. Nutrient 'excess' conditions in T2D with hyperglycemia, elevated lipids and branched-chain amino acids significantly alter the functions of immune cells including neutrophils. Neutrophils are metabolically active cells and utilizes energy from glycolysis, stored glycogen and β-oxidation while depending on the pentose phosphate pathway for NADPH for performing effector functions such as chemotaxis, phagocytosis and forming extracellular traps. Metabolic changes in T2D result in constitutive activation and impeded acquisition of effector or regulatory activities of neutrophils and render T2D subjects for recurrent infections. Increased flux through the polyol and hexosamine pathways, elevated production of advanced glycation end products (AGEs), and activation of protein kinase C isoforms lead to (a) an enhancement in superoxide generation; (b) the stimulation of inflammatory pathways and subsequently to (c) abnormal host responses. Neutrophil dysfunction diminishes the effectiveness of wound healing, successful tissue regeneration and immune surveillance against offending pathogens. Hence, Metabolic reprogramming in neutrophils determines frequency, severity and duration of infections in T2D. The present review discusses the influence of the altered immuno-metabolic axis on neutrophil dysfunction along with challenges and therapeutic opportunities for clinical management of T2D-associated infections.

Association between hypertension and the prevalence of liver steatosis and fibrosis

BACKGROUND

Hypertension (HTN) and non-alcoholic fatty liver disease (NAFLD) frequently coexist and share pathophysiological symptoms. Based on the liver stiffness measurement and controlled attenuation parameter obtained by performing liver transient ultrasound elastography (TUE), we determined the relationship between HTN status and the rates of liver steatosis and fibrosis in this study.

METHODS

To perform this cross-sectional study, data were obtained from the National Health and Nutrition Examination Survey for 2017-March 2020 Pre-pandemic cycle. The relationship between HTN and the rates of liver steatosis and fibrosis was analyzed by constructing a multivariate logistic regression model. The VCTE was performed using a FibroScan® system (model 502, V2 Touch), and CAP was measured at ≥ 274 dB/m for liver steatosis, and the LSM result (median, ≥ 8 kPa) confirmed fibrosis. We also conducted subgroup analyses based on the age, sex, ethnicity, and body mass index (BMI) of the patients.

RESULTS

In total, 4,705 participants were recruited, including 2,287 participants with HTN and 2,418 without HTN. After adjusting possible confounders, HTN was positively related to the liver steatosis rate (OR = 1.4, 95% CI: 1.1-1.8). Such HTN-associated prevalence was higher among males (OR = 1.6, 95% CI: 1.1-2.2), non-Hispanic African American individuals (OR = 2.1, 95% CI: 1.1-3.7), and participants with BMI ≥ 25 < 30 kg/m² (OR = 1.7, 95% CI: 1.1-2.5). Additionally, HTN was positively associated with the fibrosis rate (OR = 2.0, 95% CI: 1.3-3.0), especially among females (OR = 2.6, 95% CI: 1.3-5.2), among individuals who were 40-59 years old (OR = 2.1, 95% CI: 1.0-4.3), 60-80 years old (OR = 2.4, 95% CI:1.3-4.6), non-Hispanic Caucasian (OR = 2.9, 95% CI: 1.5-5.6), among those with BMI ≥ 25 < 30 kg/m² (OR = 3.0, 95% CI: 1.1-8.2), and those with BMI ≥ 30 kg/m² (OR = 2.1, 95% CI: 1.4-3.2).

CONCLUSION

The results of this study revealed that HTN status was associated with higher rates of liver steatosis and fibrosis, particularly in subjects with BMI ≥ 25 kg/m². The ethnicity of the participants also had an impact on the relationship.

Identification and validation of diagnostic biomarkers of coronary artery disease progression in type 1 diabetes via integrated computational and bioinformatics strategies

OBJECTIVE

Our study aimed to identify early peripheral blood diagnostic biomarkers and elucidate the immune mechanisms of coronary artery disease (CAD) progression in patients with type 1 diabetes mellitus (T1DM).

METHODS

Three transcriptome datasets were retrieved from the Gene Expression Omnibus (GEO) database. Gene modules associated with T1DM were selected with weighted gene co-expression network analysis. Differentially expressed genes (DEGs) between CAD and acute myocardial infarction (AMI) peripheral blood tissues were identified using limma. Candidate biomarkers were selected with functional enrichment analysis, node gene selection from a constructed protein-protein interaction (PPI) network, and 3 machine learning algorithms. Candidate expression was compared, and the receiver operating characteristic curve (ROC) and nomogram were constructed. Immune cell infiltration was assessed with the CIBERSORT algorithm.

RESULTS

A total of 1283 genes comprising 2 modules were detected as the most associated with T1DM. In addition, 451 DEGs related to CAD progression were identified. Among them, 182 were common to both diseases and mainly enriched in immune and inflammatory response regulation. The PPI network yielded 30 top node genes, and 6 were selected using the 3 machine learning algorithms. Upon validation, 4 genes (TLR2, CLEC4D, IL1R2, and NLRC4) were recognized as diagnostic biomarkers with the area under the curve (AUC) > 0.7. All 4 genes were positively correlated with neutrophils in patients with AMI.

CONCLUSION

We identified 4 peripheral blood biomarkers and provided a nomogram for early diagnosing CAD progression to AMI in patients with T1DM. The biomarkers were positively associated with neutrophils, indicating potential therapeutic targets.

Effect of insulin resistance on CAC scores in cancer survivors

BACKGROUND

Many ca. survivors exhibit signs of IR, an important risk factor for the development of CAD. CAC scans offer a risk assessment of CV disease before cardiac damage has occurred. We investigated how IR affects CAC scores in cancer survivors.

OBJECTIVES

The aim of this study was to show that CAC scores differ significantly between insulin-sensitive- and -resistant cancer survivors.

METHODS

We enrolled 90 cancer survivors of a large community hospital from March 2021 to January 2022 into this pilot study. Patients were subdivided into three groups: insulin-sensitive (IS), insulin-resistant/prediabetic and insulin-resistant/diabetic. All patients received a CAC scan.

RESULTS

70% of asymptomatic survivors overall and 81% of asymptomatic IR patients show CAD on CAC scans. 17 CAC scans in the IS group, 6 CAC scans in the IR/prediabetic group and 5 CAC scans in the IR/diabetic group showed an Agatston score of 0. The p-value between the three groups was statistically significant (p = 0.005) whereas the IR/prediabetic- and the IR/diabetic group did not differ statistically from each other. The mean MESA 10-year CHD risk with CAC was 7.8. There was a highly significant difference between the 3 groups (p < 0.001). The two IR groups did not differ statistically (p = 0.076).

CONCLUSIONS

Survivors with IR including prediabetes have less frequent zero CAC scores than insulin-sensitive survivors. Our study also showed that IR including prediabetes significantly increases the MESA 10-yr. CHD Risk with CAC in cancer survivors. This trial highlights the importance of screening survivors for IR and draws attention to the association of IR to CAC not only in diabetes but also in prediabetes. The high fraction of asymptomatic survivors with CAD is concerning and calls for further investigation. CAC scans are an inexpensive and efficient way of screening asymptomatic cancer survivors for CAD.

Cardiovascular complications in insulin resistance and endocrine diseases

Cerebrovascular diseases, such as stroke and cardiovascular disease, are one of the leading causes of death in Japan. Type 2 diabetes is the most common form of diabetes and an important risk factor for these diseases. Among various pathological conditions associated with type 2 diabetes, insulin resistance has already been reported to be an important risk factor for diabetic complications. The major sites of insulin action in glucose metabolism in the body include the liver, skeletal muscle, and adipose tissue. However, insulin signaling molecules are also constitutively expressed in vascular endothelial cells, vascular smooth muscle, and monocytes/macrophages. Forkhead box class O family member proteins (FoxOs) of transcription factors play important roles in regulating glucose and lipid metabolism, oxidative stress response and redox signaling, and cell cycle progression and apoptosis. FoxOs in vascular endothelial cells strongly promote arteriosclerosis by suppressing nitric oxide production, enhancing inflammatory response, and promoting cellular senescence. In addition, primary aldosteronism and Cushing's syndrome are known to have adverse effects on the cardiovascular system, apart from hypertension, diabetes, and dyslipidemia. In the treatment of endocrine disorders, hormonal normalization by surgical treatment and receptor antagonists play an important role in preventing cardiovascular complications.

Association of the triglycerides and glucose index and the homeostatic model assessment of insulin resistance with lipoprotein(a), apolipoprotein AI, and apolipoprotein B concentrations in children with normal-weight

The aim of this study was to compare the association of the triglycerides and glucose (TyG) index and homeostatic model assessment of insulin resistance (HOMA-IR) with lipoprotein(a) (lp[a]), apolipoprotein AI (apoAI), and apoliprotein B (apoB) concentrations in children with normal-weight. Children with normal weight aged 6-10 years and Tanner 1 stage were included in a cross-sectional study. Underweight, overweight, obesity, smoking, alcohol intake, pregnancy, acute or chronic illnesses, and any kind of pharmacological treatment were exclusion criteria. According to the lp(a) levels, children were allocated into the groups with elevated concentrations and normal values. A total of 181 children with normal weight and an average age of 8.4 ± 1.4 years were enrolled in the study. The TyG index showed a positive correlation with lp(a) and apoB in the overall population (r = 0.161 and r = 0.351, respectively) and boys (r = 0.320 and r = 0.401, respectively), but only with apoB in the girls (r = 0.294); while the HOMA-IR had a positive correlation with lp(a) levels in the overall population (r = 0.213) and boys (r = 0.328). The linear regression analysis showed that the TyG index is associated with lp(a) and apoB in the overall population (B = 20.72; 95%CI 2.03-39.41 and B = 27.25; 95%CI 16.51-37.98, respectively) and boys (B = 40.19; 95%CI 14.50-65.7 and B = 29.60; 95%CI 15.03-44.17, respectively), but only with apoB in the girls (B = 24.22; 95%CI 7.90-40.53). The HOMA-IR is associated with lp(a) in the overall population (B = 5.37; 95%CI 1.74-9.00) and boys (B = 9.63; 95%CI 3.65-15.61).   Conclusion: The TyG index is associated with both lp(a) and apoB in children with normal-weight. What is Known: • The triglycerides and glucose index has been positively associated with an increased risk of cardiovascular disease in adults. What is New: • The triglycerides and glucose index is strongly associated with lipoprotein(a) and apolipoprotein B in children with normal-weight. • The triglycerides and glucose index may be a useful tool to identify cardiovascular risk in children with normal-weight.

Association of triglyceride-glucose index with atherosclerotic cardiovascular disease and mortality among familial hypercholesterolemia patients

BACKGROUND

Familial hypercholesterolemia (FH) is an inherited metabolic disorder with a high level of low-density lipoprotein cholesterol and the worse prognosis. The triglyceride-glucose (TyG) index, an emerging tool to reflect insulin resistance (IR), is positively associated with a higher risk of atherosclerotic cardiovascular disease (ASCVD) in healthy individuals, but the value of TyG index has never been evaluated in FH patients. This study aimed to determine the association between the TyG index and glucose metabolic indicators, insulin resistance (IR) status, the risk of ASCVD and mortality among FH patients.

METHODS

Data from National Health and Nutrition Examination Survey (NHANES) 1999-2018 were utilized. 941 FH individuals with TyG index information were included and categorized into three groups: < 8.5, 8.5-9.0, and > 9.0. Spearman correlation analysis was used to test the association of TyG index and various established glucose metabolism-related indicators. Logistic and Cox regression analysis were used to assess the association of TyG index with ASCVD and mortality. The possible nonlinear relationships between TyG index and the all-cause or cardiovascular death were further evaluated on a continuous scale with restricted cubic spline (RCS) curves.

RESULTS

TyG index was positively associated with fasting glucose, HbA1c, fasting insulin and the homeostatic model assessment of insulin resistance (HOMA-IR) index (all p < 0.001). The risk of ASCVD increased by 74% with every 1 unit increase of TyG index (95%CI: 1.15-2.63, p = 0.01). During the median 114-month follow-up, 151 all-cause death and 57 cardiovascular death were recorded. Strong U/J-shaped relations were observed according to the RCS results (p = 0.0083 and 0.0046 for all-cause and cardiovascular death). A higher TyG index was independently associated with both all-cause death and cardiovascular death. Results remained similar among FH patients with IR (HOMA-IR ≥ 2.69). Moreover, addition of TyG index showed helpful discrimination of both survival from all-cause death and cardiovascular death (p < 0.05).

CONCLUSION

TyG index was applicable to reflect glucose metabolism status in FH adults, and a high TyG index was an independent risk factor of both ASCVD and mortality.

Association between triglyceride glucose index and subclinical left ventricular systolic dysfunction in patients with type 2 diabetes

BACKGROUND

The triglyceride glucose (TyG) index has been considered a new biomarker for the diagnosis of angiocardiopathy and insulin resistance. However, the association of the TyG index with subclinical left ventricular (LV) systolic dysfunction still lacks comprehensive exploration. This study was carried out to examine this relationship in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 150 T2DM patients with preserved LV ejection fraction (LVEF ≥ 50%) from June 2021 to December 2021 were included in this study. The subclinical LV function was evaluated through global longitudinal strain (GLS), with the predefined GLS < 18% as the cutoff for subclinical LV systolic dysfunction. The TyG index calculation was obtained according to ln (fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2), which was then stratified into quartiles (TyG index-Q).

RESULTS

Analyses of clinical characteristics in the four TyG indexes-Q (Q1 (TyG index ≤ 8.89) n = 38, Q2 (8.89 < TyG index ≤ 9.44) n = 37, Q3 (9.44 < TyG index ≤ 9.83) n = 38, and Q4 (TyG index > 9.83) n = 37) were conducted. A negative correlation of the TyG index with GLS (r = -0.307, P < 0.001) was revealed according to correlation analysis. After gender and age were adjusted in multimodel logistic regression analysis, the higher TyG index (OR 6.86; 95% CI 2.44 to 19.30; P < 0.001, Q4 vs Q1) showed a significant association with GLS < 18%, which was still maintained after further adjustment for related clinical confounding factors (OR 5.23, 95% CI 1.12 to 24.51, p = 0.036, Q4 vs Q1). Receiver operator characteristic analysis indicated a diagnostic capacity of the TyG index for GLS < 18% (area under curve: 0.678; P < 0.001).

CONCLUSIONS

A higher TyG index had a significant association with subclinical LV systolic dysfunction in T2DM patients with preserved ejection fraction, and the TyG index may have the potential to exert predictive value for myocardial damage.

The impact of the metabolic score for insulin resistance on cardiovascular disease: a 10-year follow-up cohort study

PURPOSE

To investigate whether the metabolic score for insulin resistance (METS-IR) is associated with an increased risk of cardiovascular disease (CVD).

METHODS

A total of 6489 participants aged 35-70 years without a history of CVD were included in this prospective cohort study. The median follow-up time was 10.6 years. The METS-IR was calculated as ln [2 × FPG (mg/dL) + fasting TG (mg/dL)] × BMI (kg/m²)/ln [HDL-C (mg/dL)]. The primary outcome was CVD, defined as the composite of coronary heart disease (CHD) and stroke.

RESULTS

During follow-up, 396 individuals developed CVD. Kaplan-Meier survival curves by quintiles of METS-IR showed statistically significant differences (log-rank test, P < 0.001). Multivariate Cox regression analysis showed that the hazard ratio [95% confidence interval (95% CI)] of CVD was 1.80 (1.24-2.61) in quintile 5 and 1.17 (1.05-1.31) for per standard deviation (SD) increase in METS-IR. In subgroup analysis, the significant association between METS-IR and CVD was mainly observed among females and subjects without diabetes mellitus. A significant interaction was found between gender and METS-IR (P-interaction = 0.001). Moreover, adding METS-IR to models with traditional risk factors yielded a significant improvement in discrimination and reclassification of incident CVD.

CONCLUSION

The elevated METS-IR was independently associated with incident CVD, suggesting that the METS-IR might be a valuable indicator for risk stratification and early intervention of CVD.

Effect of periodontal therapy on insulin resistance in adults with dysglycemia and periodontitis: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aimed to address whether non-surgical periodontal therapy (NSPT) can affect insulin resistance, estimated by the homeostasis model assessment (HOMA), in adults with prediabetes or type 2 diabetes mellitus and periodontitis.

MATERIALS AND METHODS

Six electronic databases and the gray literature were systematically searched for interventional studies reporting NSPT effect on insulin resistance. Seven studies met the eligibility criteria to be synthesized in the qualitative analysis, six reporting change in HOMA-IR, three reporting change in HOMA-%S, and two in HOMA-β. Among them, four were pooled in a meta-analysis of standardized mean difference (SMD) of HOMA-IR; comparing pre- and post-intervention values, three were pooled considering HOMA-%S as outcome, and two studies were summarized considering SMD of HOMA-%S between intervention and control groups. HOMA-β results were qualitatively synthetized.

RESULTS

With low level of certainty, NSPT significantly reduced HOMA-IR, when compared with pre-intervention data (SMD, -0.35, 95% CI -0.63 to 0.07, p=0.02). There were no significant changes in HOMA-%S or in HOMA-β scores. The level of certainty was very low and moderate, respectively.

CONCLUSIONS

Assertions about a causal link between NSPT and insulin resistance are weak and conflicting, although our more robust results point out to the absence of effect. .

CLINICAL RELEVANCE

Because further high-quality studies assessing the relationship between periodontitis and insulin resistance are need, the findings of the current systematic review are limited to give recommendations for clinicians. However, while identifying a lack of research in humans with T2D concerning periodontitis and insulin resistance, this study reinforces the need of multicenter well-designed randomized clinical trials.

A transdermal treatment with MC903 ameliorates diet-induced obesity by reducing visceral fat and increasing myofiber thickness and energy consumption in mice

AIM

MC903 is a synthetic derivative of vitamin D3 that has been designed to diminish its impact on calcium metabolism and is clinically used as a transdermal reagent for psoriasis. Animal studies showed that an oral or intraperitoneal vitamin D3 treatment prevented the development of obesity. In contrast, the bioavailability of orally administered vitamin D3 is reported to be low in obese patients. In the current study, we aimed to investigate the impact of a transdermal treatment with MC903 in established obese mice. We further studied the underlying mechanisms of MC903-mediated metabolic improvement.

MATERIALS AND METHODS

Male C57BL/6 J mice were fed standard chow or a 60% high-fat diet (HFD) for 7 weeks, and a transdermal treatment with MC903 on the ear auricle was initiated thereafter. The metabolic profiles of mice were analyzed during 4 weeks of treatment, and mice were dissected for histological and gene expression analyses. The direct impacts of MC903 and vitamin D3 were investigated using 3T3-L1 adipocytes and C2C12 myotubes in vitro.

RESULTS

HFD-fed mice showed significant increases in body and epididymal white adipose tissue (eWAT) weights with enlarged adipocytes. They exhibited glucose intolerance, decreased oxygen consumption, and chronic inflammation in eWAT. The transdermal treatment with MC903 significantly ameliorated these metabolic abnormalities in HFD-fed mice without affecting food consumption. In accordance with enhanced energy metabolism, myofiber diameters and the expression of uncoupling protein 3 (UCP3) in the gastrocnemius and soleus muscle were significantly increased in MC903-treated HFD mice. In addition, vitamin D3 and MC903 both suppressed adipogenic differentiation and enhanced lipolysis in 3T3-L1 adipocytes, and increased UCP3 expression in cultured C2C12 myotubes. Furthermore, MC903 increased oxygen consumption and UCP3 knockdown significantly decreased them in C2C12 myotubes.

CONCLUSIONS

A transdermal treatment with MC903 increased myofiber diameter and energy metabolism and decreased visceral fat accumulation, thereby improving obesity and glucose intolerance in mice.

7,8-Dihydroxyflavone Attenuates Inflammatory Response and Insulin Resistance Induced by the Paracrine Interaction between Adipocytes and Macrophages

Obesity-induced inflammation and insulin resistance are mediated by macrophage infiltration into adipose tissue. We investigated the effects of 7,8-dihydroxyflavone (7,8-DHF), a flavone found in plants, on the inflammatory response and insulin resistance induced by the interaction between adipocytes and macrophages. Hypertrophied 3T3-L1 adipocytes were cocultured with RAW 264.7 macrophages and treated with 7,8-DHF (3.12, 12.5, and 50 μM). The inflammatory cytokines and free fatty acid (FFA) release were evaluated by assay kits, and signaling pathways were determined by immunoblotting. Coculture of adipocytes and macrophages increased inflammatory mediators, such as nitric oxide (NO), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) and FFA secretion but suppressed the production of anti-inflammatory adiponectin. 7,8-DHF counteracted the coculture-induced changes (p < 0.001). 7,8-DHF also inhibited c-Jun N-terminal kinase (JNK) activation and blocked nuclear factor kappa B (NF-κB) nuclear translocation in the coculture system (p < 0.01). In addition, adipocytes cocultured with macrophages did not increase glucose uptake and Akt phosphorylation in response to insulin. However, 7,8-DHF treatment recovered the impaired responsiveness to insulin (p < 0.01). These findings show that 7,8-DHF alleviates inflammation and adipocyte dysfunction in the coculture of hypertrophied 3T3-L1 adipocytes and RAW 264.7 macrophages, indicating its potential as a therapeutic agent for obesity-induced insulin resistance.

Nomogram model for the risk of insulin resistance in obese children and adolescents based on anthropomorphology and lipid derived indicators

OBJECTIVE

This study aims to screen for measures and lipid-derived indicators associated with insulin resistance (IR) in obese children and adolescents and develop a nomogram model for predicting the risk of insulin resistance.

METHODS

A total of 404 eligible obese children and adolescents aged 10-17 years were recruited for this study from a summer camp between 2019 and 2021. The risk factors were screened using the least absolute shrinkage and selection operator (LASSO)-logistic regression model, and a nomogram model was developed. The diagnostic value of the model was evaluated by plotting the receiver operator characteristic curve and calculating the area under the curve. Internal validation was performed using the Bootstrap method, with 1000 self-samples to evaluate the model stability. The clinical applicability of the model was assessed by plotting the clinical decision curve.

RESULTS

On the basis of the LASSO regression analysis results, three lipid-related derivatives, TG/HDL-c, TC/HDL-c, and LDL-c/HDL-c, were finally included in the IR risk prediction model. The nomogram model AUC was 0.804 (95% CI: 0.760 to 0.849). Internal validation results show a C-Index of 0.799, and the mean absolute error between the predicted and actual risks of IR was 0.015. The results of the Hosmer-Lemeshow goodness-of-fit test show a good model prediction (χ² = 9.523, P = 0.300).

CONCLUSION

Three early warning factors, TG/HDL-c, TC/HDL-c, and LDL-c/HDL-c, were screened, which can effectively predict the risk of developing IR in obese children and adolescents, and the nomogram model has an eligible diagnostic value.

Empagliflozin versus sitagliptin for ameliorating intrahepatic lipid content and tissue-specific insulin sensitivity in patients with early-stage type 2 diabetes with non-alcoholic fatty liver disease: A prospective randomized study

AIM

To compare the effects of sodium-glucose co-transporter-2 (SGLT2) inhibitors and dipeptidyl peptidase-4 inhibitors on ectopic fat accumulation and tissue-specific insulin sensitivity.

MATERIALS AND METHODS

This randomized controlled trial enrolled 44 patients with type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). They were randomly assigned to receive either empagliflozin 10 mg/day or sitagliptin 100 mg/day for 12 weeks. The primary endpoint was the change in intrahepatic lipid content (IHL) measured using proton magnetic resonance spectroscopy (¹ H-MRS). The secondary endpoints included intramuscular and extramuscular lipid content seen in ¹ H-MRS, body composition seen through dual-energy X-ray absorptiometry and tissue-specific insulin sensitivity shown through hyperinsulinaemic-euglycaemic clamp using stable isotopic glucose. Liver biopsy samples were pathologically evaluated at baseline.

RESULTS

At baseline, the mean duration of diabetes, HbA1c level and IHL were 3.7 years, 7.2% and 20.9%, respectively. The median NAFLD activity score was 3.0. IHL was significantly more decreased in the empagliflozin group than that in the sitagliptin group (between-group difference was -5.2% ± 1.1% and -1.9% ± 1.2%, respectively, (95% confidence interval); -3.3 (-6.5, -0.1), P = .044). However, there were no significant between-group differences in the change of insulin sensitivity in the liver, muscle or adipose tissues. Interestingly, hepatic insulin sensitivity was significantly increased only in the empagliflozin group and was significantly negatively associated with the change in IHL.

CONCLUSIONS

Empagliflozin significantly improves hepatic steatosis compared with sitagliptin, and this may protect against subsequent hepatic insulin resistance. Early administration of SGLT2 inhibitors is preferable for T2D patients with NAFLD.

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.

Association between triglyceride-glucose index and arterial stiffness reflected by carotid pulse-wave velocity in stage 1 hypertension and individuals with normal/elevated blood pressure

Evidence of the triglyceride-glucose (TyG) index as an independent predictor of arterial stiffness in stage 1 hypertension patients is scarce. This study aimed to explore the association between TyG index and arterial stiffness in this population. A total of 1041 individuals from 32 centers with normal/elevated blood pressure (BP, <130/80 mmHg; 345 men (33%); median age, 37 years) and 585 stage 1 hypertension patients (BP ≥130/80 and <140/90 mmHg; 305 men (52%); median age, 47 years) were prospectively enrolled. Arterial stiffness was determined by measuring carotid ultrafast pulse-wave velocity (ufPWV). TyG index was calculated as ln (fasting triglyceride (TG) × fasting blood glucose/2). Patients with a higher TyG index tended to have higher ufPWV. The TyG index was positively associated with ufPWV at the end of systole in stage 1 hypertension patients after adjusting for confounding factors (β for per unit .48), and restricted cubic spline analysis confirmed a linear association. Subgroup analyses in terms of age, sex, and body mass index yielded similar results. However, no significant relationship was observed between the TyG index and ufPWV in the population with normal/elevated BP. The fully adjusted β between ufPWV and the TyG index was higher than the TG/high-density lipoprotein cholesterol ratio, TG, and pulse pressure. In conclusion, patients with a higher TyG index had greater arterial stiffness, and the TyG index independently and positively correlated with arterial stiffness in stage 1 hypertension patients. The TyG index may provide a simple and reliable marker to monitor arterial stiffness in hypertensive patients.

Cardiovascular risk factors in diabetic patients with and without metabolic syndrome: a study based on the Rafsanjan cohort study

Cardiovascular disease (CVD) is the leading cause of death and disability in people with diabetes mellitus (DM), since finding the correlation between DM and CVD risk factors can be effective in preventing the incidence of morbidity and mortality in patients. This study aimed to determine the prevalence of cardiovascular risk factors in people with and without metabolic syndrome (MtS) in DM. This cross-sectional study was part of the Rafsanjan Cohort Study as part of the comprehensive Persian (Prospective Epidemiological Research Studies in IRAN) on 35-70-year old adults with and without MtS in DM. Indicators of CVD risk factors, including gender, age, blood pressure, dyslipidemia, smoking, alcohol consumption, fasting blood sugar, creatinine, blood urea, waist circumference, body mass index, family history, physical inactivity, and fruit and vegetable consumption, were collected in the Persian Cohort Questionnaire. The data was analyzed by SPSS software version 22. The prevalence of MtS in 1933 participants was estimated to be 80% (95% confidence interval 78.1-81.8%). In the logistic regression model, smoking, alcohol consumption, and triglycerides were identified as the factors associated with MtS. Our results show that, based on our study, the prevalence of cardiovascular risk factors in DM was high. The suggested solutions in this field are to reduce smoking and alcohol consumption, as well as to control hypertension, hyperlipidemia, and being overweight.

The association of meal-specific food-based dietary inflammatory index with cardiovascular risk factors and inflammation in a sample of Iranian adults

BACKGROUND

This study aimed to evaluate the association of meals-specific food-based dietary inflammatory index (FDII), with cardiovascular (CVD) risk factors and inflammation among Iranian adults.

METHODS

In this cross-sectional study, we recruited 816 participants living in Tehran via two-staged cluster sampling. Three non-consecutive 24-h dietary recalls (two working days and one day off) were obtained from individuals to specify the main meals and meal-specific FDIIs. Anthropometric measures were done. Insulin and high-sensitivity c-reactive protein (hs-CRP) were measured. Multiple linear regressions were used to investigate the association of FDII with Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), hs-CRP, Triglyceride Glucose Index (TyG), and Lipid Accumulation Product Index (LAP).

RESULTS

The range of FDIIs for breakfast, lunch, and dinner were (-2.47,1.98), (-2.66,3.23) and (-4.09,3.13) in order, and the mean age was 42.2 ± 10.5 years. We found that there was no significant association between FDII and hs-CRP level in the three meals (β = -0.003; 95% CI: -0.030, 0.025 for breakfast,β = -0.020; 95% CI: -0.041, 0.001 for lunch, and β = 0.006; 95% CI: -0.016, 0.028 for dinner) after adjusting for age, sex, education, occupation, maritage, physical activity, smoking, morningness-eveningness score, energy, body mass index, and other FDIIs. Also, we found no significant association between breakfast, lunch, and dinner-specific FDII and HOMA-IR (β = -0.368, -0.223, 0.122), TyG index (β = -0.009, 0.060, -0.057) and LAP (β = 2.320, -0.278, -0.297).

CONCLUSIONS

We found no associations between meal-based FDII scores and CVD and inflammation. Further research of prospective nature is needed to confirm these findings.

Role of prostaglandin E2 in macrophage polarization: Insights into atherosclerosis

Atherosclerosis, a trigger of cardiovascular disease, poses grave threats to human health. Although atherosclerosis depends on lipid accumulation and vascular wall inflammation, abnormal phenotypic regulation of macrophages is considered the pathological basis of atherosclerosis. Macrophage polarization mainly refers to the transformation of macrophages into pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes, which has recently become a much-discussed topic. Increasing evidence has shown that M2 macrophage polarization can alleviate atherosclerosis progression. PGE₂ is a bioactive lipid that has been observed to be elevated in atherosclerosis and to play a pro-inflammatory role, yet recent studies have reported that PGE₂ promotes anti-inflammatory M2 macrophage polarization and mitigates atherosclerosis progression. However, the mechanisms by which PGE₂ acts remain unclear. This review summarizes current knowledge of PGE₂ and macrophages in atherosclerosis. Additionally, we discuss potential PGE₂ mechanisms of macrophage polarization, including CREB, NF-κB, and STAT signaling pathways, which may provide important therapeutic strategies based on targeting PGE₂ pathways to modulate macrophage polarization for atherosclerosis treatment.

Prognostic significance of the triglyceride-glucose index for patients with ischemic heart failure after percutaneous coronary intervention

BACKGROUND

In previous studies, the TyG index (triglyceride-glucose index) has been proven to be closely associated with the prognosis of cardiovascular disease. However, the impact of TyG index on the prognosis of patients with ischemic HF (heart failure) undergoing PCI (percutaneous coronary intervention) is still unclear.

METHOD

In this study, 2055 patients with ischemic HF were retrospectively enrolled and classified into four groups based on quartiles of the TyG index. The primary endpoint was MACE (major adverse cardiovascular events) consisting of all-cause mortality, non-fatal MI (myocardial infarction), and any revascularization. The incidence of the endpoints among the four groups was assessed through Kaplan-Meier survival analysis. The independent correlation between TyG index and endpoints was analyzed with multivariate Cox regression models. Besides, the RCS (restricted cubic spline) analysis was performed to examine the nonlinear relationship between TyG index and MACE.

RESULT

The incidence of MACE was significantly higher in participants with a higher TyG index. The positive association between the TyG index and MACE was also confirmed in the Kaplan-Meier survival analyses. Multivariate cox proportional hazards analysis indicated that the TyG index was independently associated with the increased risk of MACE, regardless of whether TyG was a continuous [TyG, per 1-unit increase, HR (hazard ratio) 1.41, 95% CI (confidence interval) 1.22-1.62, P < 0.001] or categorical variable [quartile of TyG, the HR (95% CI) values for quartile 4 was 1.92 (1.48-2.49), with quartile 1 as a reference]. In addition, the nonlinear association of TyG index with MACE was shown through RCS model and the risk of MACE increased as the TyG index increased in general (Nonlinear p=0.0215). Besides, no obvious interaction was found in the association of TyG with MACE between the DM (diabetes mellitus) group and the no-DM group.

CONCLUSION

Among patients with ischemic HF undergoing PCI, the TyG index was correlated with MACE independently and positively.

Vitamin D deficiency leads to the abnormal activation of the complement system

Vitamin D deficiency can damage the human immune system, and the complement system is a key component of the immune system. This study aimed to elucidate the mechanism by which vitamin D affects the immune system by analyzing the changes in the protein expression of the complement system under different vitamin D levels. We selected 40 participants and divided them into three groups according to their serum levels of 25-hydroxyvitamin D (25(OH)VD): group A, 25(OH)VD ≥ 40 ng/mL; group B, 30 ng/mL ≤ 25(OH)VD < 40 ng/mL; and group C, 25(OH)VD < 30 ng/mL. Serum samples were subjected to biochemical analysis, followed by proteomic analysis using high-throughput untargeted proteomic techniques. Vitamin D deficiency increased the levels of fasting blood sugar, fasting serum insulin, and homeostasis model assessment (HOMA) of insulin resistance and decreased the secretion of HOMA of β-cell function, which led to insulin resistance and glucose metabolism disorder. Moreover, vitamin D deficiency resulted in the abnormal expression of 56 differential proteins, among which the expression levels of complement factor B, complement component C9, inducible co-stimulator ligand, and peptidase inhibitor 16 significantly changed with the decrease in vitamin D content. Functional enrichment analysis of these differential proteins showed that they were mainly concentrated in functions and pathways related to insulin secretion and inflammation. In conclusion, vitamin D deficiency not only contributes to insulin resistance and glucose metabolism disorder but also causes abnormal protein expression, resulting in the abnormal activation of the complement system. This study provides a novel theoretical basis for further studies on the relationship between vitamin D and the immune system.

Activation of POMC neurons to adiponectin participating in EA-mediated improvement of high-fat diet IR mice

Background

Insulin resistance (IR) is one of the common pathological manifestations of metabolic-related diseases, and the prevalence of relevant diseases is high. Acupuncture is beneficial to IR patients, but the central mechanism underlying this treatment remains unclear. This study provides mechanistic insights into how electroacupuncture (EA) improves IR through the response of Pro-opiomelanocortin (POMC) neurons to adiponectin (Adipo).

Methods

Glucose tolerance tests (GTT), Insulin tolerance tests (ITT) and fasting blood glucose (FBG) were detected by glucometer. Serum insulin, Adipo and skeletal muscle adiponectin receptor 1 (AdipoR1) protein levels were examined by ELISA. Homeostasis model assessment estimated insulin resistance (HOMA-IR) was calculated using the following formula: HOMA-IR = fasting insulin (FINS) (mU/L) × FBG (mmol/L)/22.5. The expression levels of AdipoR1 and Adipo mRNA in skeletal muscle were detected by real-time PCR quantification. The co-marking of c-Fos/AdipoR1 and POMC neurons were investigated using immunofluorescence. Spontaneous excitatory postsynaptic currents (sEPSCs) of POMC neurons and the response of POMC neurons to Adipo were detected via electrophysiology.

Results

EA significantly ameliorated HFD-induced impairment of GTT, ITT, FBG, and HOMA-IR which was correlated with recovery of the expression level of AdipoR1 and Adipo in skeletal muscle. The improved response of POMC neurons to Adipo in the hypothalamus may be a key factor in correcting abnormal glucose tolerance and improving IR.

Conclusion

This study demonstrates that EA can ameliorate HFD-induced impaired glucose tolerance through improved response of POMC neurons to Adipo in the hypothalamus, providing insight into the central mechanism of improving IR through EA.

Machine learning of plasma metabolome identifies biomarker panels for metabolic syndrome: findings from the China Suboptimal Health Cohort

BACKGROUND

Metabolic syndrome (MetS) has been proposed as a clinically identifiable high-risk state for the prediction and prevention of cardiovascular diseases and type 2 diabetes mellitus. As a promising "omics" technology, metabolomics provides an innovative strategy to gain a deeper understanding of the pathophysiology of MetS. The study aimed to systematically investigate the metabolic alterations in MetS and identify biomarker panels for the identification of MetS using machine learning methods.

METHODS

Nuclear magnetic resonance-based untargeted metabolomics analysis was performed on 1011 plasma samples (205 MetS patients and 806 healthy controls). Univariate and multivariate analyses were applied to identify metabolic biomarkers for MetS. Metabolic pathway enrichment analysis was performed to reveal the disturbed metabolic pathways related to MetS. Four machine learning algorithms, including support vector machine (SVM), random forest (RF), k-nearest neighbor (KNN), and logistic regression were used to build diagnostic models for MetS.

RESULTS

Thirteen significantly differential metabolites were identified and pathway enrichment revealed that arginine, proline, and glutathione metabolism are disturbed metabolic pathways related to MetS. The protein-metabolite-disease interaction network identified 38 proteins and 23 diseases are associated with 10 MetS-related metabolites. The areas under the receiver operating characteristic curve of the SVM, RF, KNN, and logistic regression models based on metabolic biomarkers were 0.887, 0.993, 0.914, and 0.755, respectively.

CONCLUSIONS

The plasma metabolome provides a promising resource of biomarkers for the predictive diagnosis and targeted prevention of MetS. Alterations in amino acid metabolism play significant roles in the pathophysiology of MetS. The biomarker panels and metabolic pathways could be used as preventive targets in dealing with cardiometabolic diseases related to MetS.

Association of Non-Dipping Blood Pressure Patterns with Diabetic Peripheral Neuropathy: A Cross-Sectional Study among a Population with Diabetes in Greece

Diabetic peripheral neuropathy (DPN) is present in 20-50% of cases with diabetes. The pathophysiology of DPN is not yet clear regarding hypertension (HTN). The aim of this study was to assess the association between the stages of DPN and HTN in a Greek population with diabetes. We examined 102 adults for diabetic neuropathy (DPN) from November 2020 to December 2021, using the Toronto Clinical Neuropathy Scale System (TCNSS) to categorize them into two groups (no/mild DPN versus medium/severe DPN). Ambulatory blood pressure monitoring was performed to evaluate their hypertensive status. Univariate and multivariate logistic regression analyses were performed to assess the association between the stage of DPN and HTN. The multivariate analysis, considering sex, age, and dipping status, did not show statistically significant associations between stages of HTN and DPN. However, in contrast to dippers, non-dippers had an almost four-times higher risk of developing medium-to-severe DPN (odds ratio (OR) 3.93; 95% confidence interval (CI) [1.33-11.64]); females, in contrast to males, had a 65% lower risk of developing moderate/severe DPN (OR 0.35; 95%CI [0.14-0.92]). In conclusion, our findings showed no statistically significant associations between DPN and HTN; however, dipping status, hyperglycemia, and female sex were shown to play a role in the pathophysiology of DPN.

Influence of age on the association between the triglyceride-glucose index and all-cause mortality in patients with cardiovascular diseases

BACKGROUND

In patients with cardiovascular diseases, it is reported that the triglyceride-glucose index (TGI) potentially indicates prognosis. However, the results are controversial. Moreover, whether age has an impact on the predictive value of TGI remains unclear.

METHODS

Participants with cardiovascular diseases were enrolled using the China Health and Retirement Longitudinal Study (CHARLS) registry. TGI was calculated as ln (triglyceride×glucose/2). The survival status was recorded every 2 years in the follow-up waves. Multivariate regression analysis was carried out to determine the relationship between TGI levels and long-term all-cause mortality in patients grouped by different age. Patients younger than 65 years old were regarded as middle-aged group. Otherwise, they were classified as old group.

RESULTS

In total, 2923 patients with cardiovascular diseases and baseline blood test results were included. After 7 years of follow-up, 242 (8.91%) patients died. Cox regression analysis revealed that higher TGI levels were associated with a higher risk of long-term all-cause mortality in middle-aged participants (hazard ratio [HR], 3.64; 95% confidence interval [CI] 1.44-9.22, P = 0.006) but not in old participants (HR 1.20, 95% CI 0.62-2.32, P = 0.594, P for interaction = 0.017), after adjusting physical activity and other factors. Kaplan-Meier estimate analysis and restricted cubic spline curves showed similar results.

CONCLUSION

TGI was a promising marker for predicting all-cause mortality in middle-aged patients after cardiovascular diseases. Patients younger than 65 years old who have a higher level of TGI may develop a higher risk of all-cause mortality, and they are encouraged to control vascular risk factors and take more physical activity to improve their prognosis. Additionally, whether intervention in regulating TGI levels is beneficial for the prognosis of these patients needs further investigation.

Association between triglyceride glucose index and worsening heart failure in significant secondary mitral regurgitation following percutaneous coronary intervention

BACKGROUND

The triglyceride glucose (TyG) index is an alternative to insulin resistance (IR) as an early indicator of worsening heart failure (HF). Patients with secondary mitral regurgitation (sMR) often experience progressive deterioration of cardiac function. This study aimed to investigate the relationship between the TyG index and worsening of HF in significant sMR (grade  ≥ 2) following percutaneous coronary intervention (PCI).

METHODS

This study enrolled participants with significant sMR following PCI from a multicenter cohort study. The patients were divided into the following 3 groups according to tertiles of TyG index: T1, TyG ≤ 8.51; T2, TyG > 8.51 to ≤ 8.98; and T3, TyG > 8.98. The main clinical outcome was worsening HF including unplanned rehospitalization or unscheduled physician office/emergency department visit due to HF and unplanned mitral valve surgery.

RESULTS

A total of 922 patients (mean ± SD age, 64.1 ± 11.0 years; 79.6% male) were enrolled. The incidence of worsening HF was 15.5% in T1, 15.7% in T2, and 26.4% in T3. In the multivariable model, the highest TyG tertile (T3 group) was more strongly correlated with worsening HF than the lowest tertile (T1 group) after adjusting for confounders (adjusted hazard ratio, 2.44; 95% confidence interval, 1.59-3.72; P < 0.001). The addition of TyG to risk factors such as N-terminal pro brain natriuretic peptide and clinical models improved the predictive ability of TyG for worsening HF.

CONCLUSIONS

Elevated preprocedural TyG index is a significant and independent risk factor for worsening HF in sMR following PCI that can be used for risk stratification.

Comprehensive Review of Cardiovascular Disease Risk in Nonalcoholic Fatty Liver Disease

Nonalcoholic Fatty Liver Disease (NAFLD) is a growing global phenomenon, and its damaging effects in terms of cardiovascular disease (CVD) risk are becoming more apparent. NAFLD is estimated to affect around one quarter of the world population and is often comorbid with other metabolic disorders including diabetes mellitus, hypertension, coronary artery disease, and metabolic syndrome. In this review, we examine the current evidence describing the many ways that NAFLD itself increases CVD risk. We also discuss the emerging and complex biochemical relationship between NAFLD and its common comorbid conditions, and how they coalesce to increase CVD risk. With NAFLD's rising prevalence and deleterious effects on the cardiovascular system, a complete understanding of the disease must be undertaken, as well as effective strategies to prevent and treat its common comorbid conditions.

Association of triglyceride-glucose index and traditional risk factors with cardiovascular disease among non-diabetic population: a 10-year prospective cohort study

BACKGROUND

The triglyceride-glucose (TyG) index is known as a reliable alternative marker of insulin resistance (IR), which has been regarded as a predictor of cardiovascular disease (CVD). However, whether TyG index can predict the risk and occurrence of CVD in non-diabetic population remains uncertain. The aim of this study was to explore the association between the TyG index and cardiovascular risk factors and to clarify the prognostic value of the TyG index for CVD, coronary heart disease (CHD) and stroke in non-diabetic general population in Eastern China.

METHODS

A total of 6095 cases without diagnosed diabetes and CVD were included. The TyG index was calculated as ln (fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2) and the participants were divided into 4 groups according to the TyG index quartiles (Q1, Q2, Q3, Q4). The primary outcome was CVD, including CHD and stroke. Cox proportional hazards regression analysis was used to investigate the association between the TyG index and the risk of CVD.

RESULTS

During the 10-year follow-up, 357 (5.9%) participants of CVD, 224 (3.7%) participants of CHD and 151 (2.5%) participants of stroke were observed. The incidence of CVD increased with the TyG index quartiles. Multivariate Cox regression analysis showed that the hazard ratios [95% confidence interval (CI)] in Q4 group were respectively 1.484 (1.074-2.051) for CVD, 1.687 (1.105-2.575) for CHD and 1.402 (0.853-2.305) for stroke compared to Q1 group. Moreover, adding the TyG index to models with traditional risk factors yielded a significant improvement in discrimination and reclassification of incident CVD and CHD.

CONCLUSIONS

The TyG index is associated with cardiovascular risk factors and can be used as a useful, low-cost predictive marker for CVD and CHD risk in non-diabetic population.

The triglycerides-glucose index and the triglycerides to high-density lipoprotein cholesterol ratio are both effective predictors of in-hospital death in non-diabetic patients with AMI

Background

The triglycerides-glucose index (TyG) and the triglycerides to high-density lipoprotein cholesterol (TG/HDL-C) are simple indicators for assessing insulin resistance in epidemiological studies. We aimed to clarify the relationship between indicators of insulin resistance and prognosis in non-diabetic acute myocardial infarction (AMI) patients.

Methods

A total of 1,648 AMI patients without diabetes were enrolled from the Department of Cardiology, Zhongda Hospital, between 2012.03 and 2018.12. The medical history, laboratory and imaging data of patients were collected through the medical record system, and all-cause death events were recorded. Pearson analysis was used to study the correlation among different variables. Logistic regression analysis was used to analyze the predictive effect of TyG and TG/HDL-C in in-hospital death of AMI patients.

Results

1. In AMI group, the TyG index was significantly increased in death groups compared to no-death groups (P = 0.025). TG/HDL-C was not significantly increased in the death group of AMI patients (P = 0.588). The patients were respectively divided into Q1-Q4 groups and T1-T4 groups according to the quartiles of TyG and TG/HDL-C. The trends of in-hospital mortality in the Q4 group of TyG and T4 group of TG/HDL-C were higher than in other groups, although these differences were not significant. 2. Pearson correlation analysis showed that TyG was positively correlated with lipid-related markers, including ApoB (r = 0.248, P < 0.001), total cholesterol (TC) (r = 0.270, P < 0.001), low-density lipoprotein cholesterol (LDL-C) (r = 0.238, P < 0.001). Spearman analysis showed that TG/HDL-C was also positively associated with TC (r = 0.107, P < 0.001), ApoB (r = 0.180, P < 0.001) and LDL-C (r = 0.164, P < 0.001). 3. Logistic regression analysis showed that TyG (OR = 3.106, 95% CI [2.122-4.547], P < 0.001) and TG/HDL-C (OR = 1.167, 95% CI [1.062-1.282], P = 0.001) were both important factors to predict the in-hospital death of AMI patients without diabetes.

Conclusions

TyG index and TG/HDL-C, as emerged simple markers of insulin resistance, were both important predictors of in-hospital death in AMI patients without diabetes.

Relationship between peripheral arterial disease severity determined by the Glass classification and triglyceride-glucose index; novel association and novel classification system

Peripheral arterial disease is a serious clinical manifestation caused by atherosclerosis. It is one common cause of morbidity and mortality worldwide. It is commonly seen in males, and its (prevelance) increases with age. It is most prevalent with smoking, hypertension, diabetes mellitus and hyperlip-idemia. Novel studies investigate the relationship between triglyceride-glucose index (TyG) and cardiovascular diseases. Studies investigating the association of this index and peripheral arterial disease and disease severity are generally done by using The Trans-Atlantic Inter-Society Consensus (TASC) classification. We aimed to study this association by using the new Global Limb Anatomic Staging System (GLASS) classification. Two hundred patients between 25 to 90 years old diagnosed with peripheral arterial disease and admitted to the hospital for peripheral arterial angiography between July 2021 and December 2021, were evaluated retrospectively with blood parameters and angiographic images. Patients were divided into two groups: moderate (group 1; n=58) and severe (group 2; n=142) according to the GLASS classification. No statistical differences were observed for comorbidities and repeated interventional pro-cedure rates (p=0.164). Triglyceride values were found to be statistically dif-ferent between groups (p=0.040). TyG was found higher in group 2 (p= 0.04). According to the binary logistic regression model, only TyG was found to have a significant effect as a diagnostic factor (p=0.011). TyG was also significantly correlated with the Rutherford (p=0.012) and GLASS classification severity (p<0.001). Peripheral arterial disease and disease severity could be easily moni-tored with simple calculable TyG. In this way, precautions could be taken, and morbidities could be prevented.

Relationship between a novel non-insulin-based metabolic score for insulin resistance (METS-IR) and coronary artery calcification

BACKGROUND AND AIMS

A novel non-insulin-based metabolic score for insulin resistance (METS-IR) index has been proposed as a simple and reliable alternative insulin resistance (IR) marker, but its the predictive value in asymptomatic adults with coronary artery calcification (CAC) remains unclear.

METHODS AND RESULTS

We enrolled 1576 participants without cardiovascular disease (CVD), who underwent multidetector computed tomography. Logistic regression, restricted cubic spline models and receiver operating characteristic (ROC) curves were used to examine the association between METS-IR, the ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) and triglyceride glucose index (TyG index) and CAC. In multivariate logistic regression analysis, the increase in METS-IR was independently associated with a higher prevalence of CAC (all P < 0.05 in Models 1-3). Furthermore, restricted cubic splines indicated that the significance of METS-IR in predicting CAC was higher than that of other IR indexes. In ROC curve analysis, without considering the P value, the area under the curve of CAC predicted by METS-IR was higher than that of other IR indexes (METS-IR, 0.607; TyG index, 0.603; TG/HDL-C, 0.577).

CONCLUSION

Compared with other IR indexes, METS-IR may have better discrimination ability in predicting the incidence of CAC in asymptomatic adults without CVD.

Differences in the impact of impaired glucose status on clinical outcomes in younger and older adults: Over a decade of follow-up in the Tehran lipid and glucose study

Introduction

Studies found that the impact of dysglycemia on microvascular, macrovascular events and mortality outcomes were different between the younger vs. older population. We aimed to investigate the age-specific association of prediabetes with clinical outcomes including type 2 diabetes (T2DM), hypertension, chronic kidney disease (CKD), cardiovascular disease (CVD), and mortality.

Materials and methods

A total of 5,970 Iranians (3,829 women) aged ≥30 years, without T2DM, were included. The age-specific (<60 and ≥60 years; minimum p-value for interaction = 0.001) multivariable-adjusted Cox regression was done to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of the impaired glucose status including impaired fasting glucose (IFG) vs. normal fasting glucose (NFG), impaired glucose tolerance (IGT) vs. normal glucose tolerance (NGT), and IFG&IGT vs. NFG/NGT with each outcome.

Results

Among individuals aged ≥60 years, the prevalence of impaired glucose status (IFG, IGT, or both) was about 2 times higher compared to those aged <60. Age-specific association between prediabetes and incident hypertension was found for those aged <60 years; [HR (95% CI); IFG: 1.38 (1.16–1.65), IGT: 1.51 (1.26–1.81), and IFG&IGT: 1.62 (1.21–2.12)]. For CVD, in all impaired glycemic states, those aged <60 were at higher significant risk [IFG: 1.39 (1.09–1.77), IGT: 1.53 (1.19–1.97), and IFG&IGT: 1.60 (1.14–2.25)]. Stratified analyses showed similar associations for IFG and IGT with non-CV mortality 1.71 (1.04–2.80) and 2.12 (1.30–3.46), respectively, and for all-cause mortality among those aged <60 years [IFG: 1.63 (1.08–2.45) and IGT: 1.82 (1.20–2.76)]. In both age groups, all glycemic status groups were significantly associated with T2DM but not with CKD and CV mortality.

Conclusions

The high prevalence of prediabetes particularly among the elderly population, limited resources, and the observed significant age differences in the impact of prediabetes states on different clinical outcomes calls for multicomponent intervention strategies by policy health makers, including lifestyle and possible pharmacological therapy, with the priority for the young Iranian population.

Triglyceride-glucose index and non-culprit coronary plaque characteristics assessed by optical coherence tomography in patients following acute coronary syndrome: A cross-sectional study

Background

Triglyceride-glucose (TyG) index, a novel surrogate marker of insulin resistance, has been demonstrated to be significantly associated with cardiovascular disease. It remains indistinct regarding the association between TyG index and non-culprit coronary plaque characteristics in patients following acute coronary syndrome (ACS).

Methods

The present study retrospectively recruited patients who were diagnosed with ACS and underwent non-culprit optical coherence tomography (OCT) examination. The study population was divided into 2 groups based on the median of TyG index, which was calculated as Ln [fasting triglyceride (TG) (mg/dL) × fasting blood glucose (FBG) (mg/dL)/2]. The non-culprit plaque characteristics were determined by interpreting OCT images in accordance with the standard of previous consensus.

Results

110 patients (54.8 ± 12.1 years, 24.5% female) with 284 non-culprit plaques were included in the current analysis. TyG index was closely associated with high-risk plaque characteristics. Elevated TyG index was consistent to be an independent indicator for thin-cap fibroatheroma (TCFA) [odds ratio (OR) for per 1-unit increase 4.940, 95% confidence interval (CI) 1.652–14.767, P = 0.004; OR for taking lower median as reference 2.747, 95% CI 1.234–7.994, P = 0.011] and ruptured plaque (OR for per 1–unit increase 7.065, 95% CI 1.910–26.133, P = 0.003; OR for taking lower median as reference 4.407, 95% CI 1.208–16.047, P = 0.025) in fully adjusted model. The predictive value of TyG index for TCFA and ruptured plaque was moderate–to–high, with the area under the receiver operating characteristic curve (AUC) of 0.754 and 0.699 respectively. The addition of TyG index into a baseline model exhibited an incremental effect on the predictive value for TCFA, manifested as an increased AUC (0.681, 95% CI 0.570–0.793 vs. 0.782, 95% CI 0.688–0.877, P = 0.042), and significant continuous net reclassification improvement (0.346, 95% CI 0.235–0.458, P < 0.001) and integrated discrimination improvement (0.221, 95% CI 0.017–0.425, P = 0.034). TyG index failed to play an incremental effect on predicting ruptured plaque.

Conclusion

TyG index, which is simply calculated from fasting TG and FBG, can be served as an important and independent risk predictor for high-risk non-culprit coronary plaques in patients following ACS.

The role of the gut microbiota in health and cardiovascular diseases

The gut microbiota is critical to human health, such as digesting nutrients, forming the intestinal epithelial barrier, regulating immune function, producing vitamins and hormones, and producing metabolites to interact with the host. Meanwhile, increasing evidence indicates that the gut microbiota has a strong correlation with the occurrence, progression and treatment of cardiovascular diseases (CVDs). In patients with CVDs and corresponding risk factors, the composition and ratio of gut microbiota have significant differences compared with their healthy counterparts. Therefore, gut microbiota dysbiosis, gut microbiota-generated metabolites, and the related signaling pathway may serve as explanations for some of the mechanisms about the occurrence and development of CVDs. Several studies have also demonstrated that many traditional and latest therapeutic treatments of CVDs are associated with the gut microbiota and its generated metabolites and related signaling pathways. Given that information, we summarized the latest advances in the current research regarding the effect of gut microbiota on health, the main cardiovascular risk factors, and CVDs, highlighted the roles and mechanisms of several metabolites, and introduced corresponding promising treatments for CVDs regarding the gut microbiota. Therefore, this review mainly focuses on exploring the role of gut microbiota related metabolites and their therapeutic potential in CVDs, which may eventually provide better solutions in the development of therapeutic treatment as well as the prevention of CVDs.

Predictive worth of estimated glucose disposal rate: evaluation in patients with non-ST-segment elevation acute coronary syndrome and non-diabetic patients after percutaneous coronary intervention

BACKGROUND

Measurement of estimated glucose disposal rate (eGDR) has been demonstrated to be an indicator of insulin resistance (IR) and a risk sign for long-term outcomes in those with ischemic heart disease and type 2 diabetes mellitus (T2DM) having coronary artery bypass grafting (CABG). After elective percutaneous coronary intervention (PCI), the usefulness of eGDR for prognosis in those with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and non-diabetes is yet unknown.

METHODS

1510 NSTE-ACS patients with non-diabetes who underwent elective PCI in 2015 (Beijing Anzhen Hospital) were included in this study. Major adverse cardio-cerebral events (MACCEs), such as all-cause mortality, non-fatal myocardial infarction, non-fatal ischemic stroke, and also ischemia-driven revascularization, were the main outcome of follow-up. The average number of follow-up months was 41.84.

RESULTS

After multivariate Cox regression tests with confounder adjustment, the occurrence of MACCE in the lower eGDR cluster was considerably higher than in the higher eGDR cluster, demonstrating that eGDR is an independent prognostic indicator of MACCEs. In particular, as continuous variate: hazard ratio (HR) of 1.337, 95% confidence interval (CI) of 1.201-1.488, P < 0.001. eGDR improves the predictive power of usual cardiovascular risk factors for the primary endpoint. Specifically, the results for the area under the receiver operating characteristic (ROC) curve, this is AUC, were: baseline model + eGDR 0.699 vs. baseline model 0.588; P for contrast < 0.001; continuous net reclassification improvement (continuous-NRI) = 0.089, P < 0.001; and integrated discrimination improvement (IDI) = 0.017, P < 0.001.

CONCLUSION

Low eGDR levels showed a strong correlation with poor NSTE-ACS prognosis for nondiabetic patients undergoing PCI.

The triglyceride glucose index is associated with future cardiovascular disease nonlinearly in middle-aged and elderly Chinese adults

OBJECTIVE

We aimed to investigate the association between triglyceride glucose index and cardiovascular disease (CVD) development in the Chinese middle-aged and elderly population using the China Health and Retirement Longitudinal Study dataset 2011-2018.

METHODS

Basic characteristics of participants, including sociodemographic information, and health conditions, were acquired. Logistic regression analyses and restricted cubic spline regression analyses were conducted to investigate the association between the triglyceride glucose index and future CVD risks. Subgroup analyses were performed to evaluate potential interaction.

RESULTS

Seven hundred fifty-three of 6114 (12.3%) participants have developed CVD in 2018 over an approximately 7-year follow-up. The logistic regression analysis exhibited that compared to the lowest triglyceride glucose index group, the multivariable OR for future CVD was 0.985 (95%CI 0.811-1.198) in the T2 triglyceride glucose index group and 1.288 (95%CI 1.068-1.555) in the T3 TyG index (P for trend 0.006). The restricted cubic spline regression analysis showed the nonlinear association between triglyceride glucose index and CVD incidence; the cut-off values were 8.07 and 8.57, respectively, after total adjustment. Gender, fast blood glucose, and triglycerides interacted with triglyceride glucose index and CVD except for BMI.

CONCLUSION

The triglyceride glucose index was nonlinearly related to the risk of future cardiovascular disease in the middle-aged and elderly Chinese population.

Role of insulin action in the pathogenesis of diabetic complications

Among the various pathological conditions associated with type 2 diabetes, insulin resistance has long been reported to be a potent risk factor for diabetic complications. The liver, skeletal muscle, and adipose tissue are the major organs of action of insulin in systemic glucose metabolism, but insulin receptors and their downstream insulin signaling molecules are also constitutively expressed in vascular endothelial cells, vascular smooth muscle, and monocytes/macrophages. Forkhead box class O family member proteins (FoxOs) of transcription factors are essential regulators of cellular homeostasis, including glucose and lipid metabolism, oxidative stress response and redox signaling, cell cycle progression and apoptosis. In vascular endothelial cells, FoxOs strongly promote atherosclerosis via suppressing nitric oxide production and enhancing inflammatory responses. In liver sinusoidal endothelial cells, FoxOs induces hepatic insulin resistance by inducing nitration of insulin receptor in hepatocytes. Insulin resistance in adipose tissue limits capacity of lipid accumulation in adipose tissue, which promotes ectopic lipid accumulation and organ dysfunction in liver, vascular, and kidney. Modulation of insulin sensitivity in adipose tissue to induce healthy adipose expansion is expected to be a promising strategy for diabetic complications.

Incremental prognostic value of triglyceride glucose index additional to coronary artery calcium score in asymptomatic low-risk population

BACKGROUND

The triglyceride glucose (TyG) index has been suggested as a reliable surrogate marker of insulin resistance which is a substantial risk factor for atherosclerotic cardiovascular disease (ASCVD). Several recent studies have shown the relationship between the TyG index and cardiovascular disease; however, the role of the TyG index in coronary artery calcification (CAC) progression has not been extensively assessed especially in low-risk population.

METHODS

We enrolled 5775 Korean adults who had at least two CAC evaluations. We determined the TyG index using ln (fasting triglycerides [mg/dL] x fasting glucose [mg/dL]/2). The CAC progression was defined as either incident CAC in a CAC-free population at baseline or an increase of ≥ 2.5 units between the square roots of the baseline and follow-up coronary artery calcium scores (CACSs) of subjects with detectable CAC at baseline.

RESULTS

CAC progression was seen in 1,382 subjects (23.9%) during mean 3.5 years follow-up. Based on the TyG index, subjects were stratified into four groups. Follow-up CACS and incidence of CAC progression were markedly elevated with rising TyG index quartiles (group I [lowest]:17.6% vs. group II:22.2% vs. group III:24.6% vs. group IV [highest]: 31.3%, p < 0.001). In multivariate logistic regression analysis, the TyG index was independent predictor of CAC progression (odds ratio: 1.57; 95% confidence interval: 1.33 to 1.81; p < 0.001) especially in baseline CACS ≤ 100 group.

CONCLUSION

The TyG index is an independent predictor of CAC progression in low-risk population. It adds incremental risk stratification over established factors including baseline CACS.

Cystatin C-based eGFR predicts cardiovascular disease in patients with overweight/obesity and hyperglycemia

Background

Although many clinical parameters have been identified as predictors for cardiovascular disease (CVD) development in the general population, the accurate predictor for CVD in patients with obesity is still unknown.

Objective

The study aimed to explore an additional risk factor and predictor for CVD in patients with overweight/obesity considering the interaction of obesity-related pathophysiology.

Methods

The Japan Obesity and Metabolic Syndrome study, a multicenter prospective study, enrolled 787 outpatients, of which 318 eligible patients were analyzed. Patients with fasting plasma glucose (FPG) levels ≥6.11 and < 6.11 mmol/L were considered to have high FPG (HFPG) and normal FPG (NFPG), respectively. Thirty-six patients who developed CVD during the 5 years follow-up were assigned to the CVD group.

Results

Cox's proportional hazards model revealed no significant association between CVD and cystatin C-based estimated glomerular filtration rate (eGFRcys) or creatinine-based eGFR (eGFRcr) in the NFPG group. In the HFPG group, lower eGFRcys, but not eGFRcr, was significantly associated with CVD development. A generalized linear mixed model demonstrated greater reduction in eGFRcys levels over time with HFPG than with NFPG. Although the CVD group showed gradual reduction in eGFRcys levels, the non-CVD group-matched using propensity scores-did not show a decline in eGFRcys levels.

Conclusions

Lower eGFRcys levels may be more accurate than eGFRcr in predicting CVD development in patients with overweight/obesity and hyperglycemia. Furthermore, eGFRcys reduction over time is associated with CVD development.

Clinical Trial Registry Number

UMIN000000559.

Do obesity, hypertension and dyslipidemia pose significant risks for coronary artery disease among Bangladeshi diabetics?

Background and objectives: For decades the global population has been experiencing diabetic epidemic. The risks related to obesity, diabetes mellitus (DM) and coronary artery diseases (CAD) are well known. This study aimed to assess the prevalence of coronary artery disease (CAD) and its related risks in Bangladeshi diabetics. Materials and methods: The study was conducted at Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM), a largest referral center for diabetes in Bangladesh. Socio-demographic and clinical history including biochemical investigation report were collected from the BIRDEM registry. The eligible criteria of study participants were: age 30 – 60 year, having DM, non-smoker, free from retinopathy, nephropathy and neuropathy. The prevalence of CAD, systolic hypertension (SHTN) and diastolic hypertension (DHTN) in the registered diabetic patients were estimated. Additionally, the study addressed the risk and predictors of CAD among those with DM. Investigations included – anthropometry, blood pressure, blood glucose, serum lipids and electrocardiogram (ECG). CAD was diagnosed on: (a) history of angina plus positive ECG - either on rest or on stress, post-myocardial infarction (MI) with Q-wave MI or non-Q-MI or echocardiographic evidences. Lipids namely triglycerides (TG), total cholesterol (T-Chol), high density lipoproteins (HDL) and low-density lipoproteins (LDL) were estimated by Hitachi-704 auto-analyzer using enzymatic method. Results: A total of 693 (M /W =295/398) participants volunteered. The prevalence of CAD, SHTN, DHTN and mean arterial hypertension (MAH) were 18.6%, 23.2%, 13.6% and 17.7%, respectively. Their mean (±SD) values of age, body mass index (BMI - kg/m2), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and mean arterial pressure (MAP) were 47 (8.6) years, 24.6 (3.5), 0.98(0.05), 0.56(0.06) and 101(11.3) mmHg, respectively. The mean (±SD) of FBG (mmol/L), T-Chol, TG and HDL (mg/dl) were 10.2 ± 4.0, 206 ± 44, 218 ± 86 and 47.5 ± 9.3 respectively. The women had significantly higher BMI (p<0.001), WHtR (p<0.001), SBP (<0.001), MAP (p<0.001), T-Chol (p<0.001) and TG (p=0.043) than men. The risk variables were categorized into quartiles and Chi-sq trend determined whether the increasing prevalence of CAD were significant. Higher quartile of age was found consistently significant (p<0.001). Of the obesity indices, only higher quartile of WHtR was significant (p< 0.05). For BP measures, higher MAP quartiles showed the trend significant (p<0.001). Likewise, for lipids, higher quartiles of TG (p<0.001) and lower quartile of HDL (p<0.001) were significant. Finally, logistic regression estimated the risk related to CAD. The highest age-quintile (>55y: 95% CI: 1.09 - 43.7) and highest TG-quintile (281mg/dl: 95% CI: 1.45-59.7) were proved to be significant predictor of CAD and HDL highest quintile (>54mg/dl) was proved to be significant protecting factor for CAD (95% CI: 0.005-0.583). Conclusion: The study observed the importance of MAP, TG, HDL, T-Chol/HDLR (T-Chol -to HDL ratio) and TG/HDLR (triglycerides-to HDL ratio) as risks for CAD among diabetics. Further study with investigations of echocardiogram, ETT, coronary angiogram and coronary calcium scoring would be helpful in confirming these findings related to CAD risks. IMC J Med Sci. 2023; 17(1): 002. DOI: https://doi.org/10.55010/imcjms.17.002 *Correspondence: M Abu Sayeed, Department of Community Medicine, Ibrahim Medical College, 1/A, Ibrahim Sarani, Segunbagicha, Dhaka 1000, Bangladesh. Email: sayeed1950@gmail.com

Association between the triglyceride-glucose index and severity of coronary artery disease

Background

The triglyceride–glucose (TyG) index, which is a reliable surrogate marker of insulin resistance (IR), has been associated with cardiovascular diseases. However, evidence of the impact of the TyG index on the severity of coronary artery disease (CAD) is limited. This study investigated the relationship between the TyG index and CAD severity of individuals with different glucose metabolic statuses.

Methods

This study enrolled 2792 participants with CAD in China between January 1, 2018 and December 31, 2021. All participants were divided into groups according to the tertiles of the TyG index as follows: T1 group, TyG index < 6.87; T2 group, TyG index ≥ 6.87 to < 7.38; and T3 group, TyG index ≥ 7.38. The glucose metabolic status was classified as normal glucose regulation, pre-diabetes mellitus (pre-DM), and diabetes mellitus according to the standards of the American Diabetes Association. CAD severity was determined by the number of stenotic vessels (single-vessel CAD versus multi-vessel CAD).

Results

We observed a significant relationship between the TyG index and incidence of multi-vessel CAD. After adjusting for sex, age, body mass index, smoking habits, alcohol consumption, hypertension, estimated glomerular filtration rate, antiplatelet drug use, antilipidemic drug use, and antihypertensive drug use in the logistic regression model, the TyG index was still an independent risk factor for multi-vessel CAD. Additionally, the highest tertile of the TyG group (T3 group) was correlated with a 1.496-fold risk of multi-vessel CAD compared with the lowest tertile of the TyG group (T1 group) (odds ratio [OR], 1.496; 95% confidence interval [CI], 1.183–1.893; P < 0.001) in the multivariable logistic regression model. Furthermore, a dose–response relationship was observed between the TyG index and CAD severity (non-linear P = 0.314). In the subgroup analysis of different glucose metabolic statuses, the T3 group (OR, 1.541; 95% CI 1.013–2.344; P = 0.043) were associated with a significantly higher risk of multi-vessel CAD in individuals with pre-DM.

Conclusions

An increased TyG index was associated with a higher risk of multi-vessel CAD. Our study indicated that TyG as an estimation index for evaluating IR could be a valuable predictor of CAD severity, especially for individuals with pre-DM.

Reducing VEGFB expression regulates the balance of glucose and lipid metabolism in mice via VEGFR1

In recent years, studies have demonstrated that vascular endothelial growth factor B (VEGFB) can affect the metabolism of fatty acids and glucose, and it is expected to become a target for the diagnosis and treatment of metabolic diseases such as obesity and diabetes. At present, the specific mechanism that VEGFB regulates lipid and glucose metabolism balance is not completely understood. The present study used systemic VEGFB gene-knockout mice to investigate the effects of downregulation of the VEGFB gene on lipid metabolism and insulin secretion, and to explore the mechanism of the VEGFB pathway involved in the regulation of glucose and lipid metabolism. The morphological changes in the liver and pancreas of mice after VEGFB gene deletion were observed under a light microscope and a scanning electron microscope, and the effects of VEGFB gene deletion on lipid metabolism and blood glucose balance were detected by a serological technique. The detection indexes included total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol. Simultaneously, fasting blood glucose, glycosylated hemoglobin A1c (HbA1c), fasting insulin and glucagon were measured. Insulin sensitivity was assessed by using the insulin tolerance tests and glucose tolerance tests, and function of β-cell islets was evaluated by using the insulin resistance index (HOMA-IR) and pancreatic β-cell secretion index (HOMA-β). Τhe protein expression changes of vascular endothelial growth factor receptor 1 (VEGFR1) and vascular endothelial growth factor receptor 2 (VEGFR2) in mouse islets were detected by western blotting and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) after the VEGFB gene was knocked down to analyze the mechanism of VEGFB that may be involved in glucose and lipid metabolism. It was observed that after VEGFB was knocked down, mouse hepatocytes exhibited steatosis and increased secretory vesicles in islet cells. The lipid metabolism indexes such as TG, TC and LDL increased significantly; however, the levels of FBS, postprandial blood glucose and HbA1c decreased, whereas the glucose tolerance increased. Serum insulin secretion increased and HOMA-IR decreased since VEGFB was knocked down. Western blotting and RT-qPCR results revealed that the expression levels of VEGFR1 and neuropilin-1 decreased after the VEGFB gene was knocked down, while the expression levels of VEGFA and VEGFR2 increased. The absence of VEGFB may be involved in the regulation of glucose and lipid metabolism in mice by activating the VEGFA/VEGFR2 signaling pathway. VEGFB is expected to become a new target for the treatment of metabolic diseases such as obesity and diabetes. At present, the mechanism of VEGFB involved in regulating lipid metabolism and glucose metabolism is not completely clear. It was identified that downregulating VEGFB improved lipid metabolism and insulin resistance. The role of VEGFB/VEGFR1 pathway and other family members in regulating glucose and lipid metabolism was detected, which provided a theoretical and experimental basis for VEGFB to affect the regulation of glucose and lipid metabolism balance.