Insulin resistance and coronary heart disease in nondiabetic individuals

Coronary artery disease risk prediction by combined stratification of low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol levels across different glucose statuses

AIM

To investigate the association between low-density lipoprotein-cholesterol (LDL-C) levels and coronary artery disease (CAD) incidence based on combining high-density lipoprotein-cholesterol (HDL-C) levels and glucose status.

MATERIALS AND METHODS

In this retrospective cohort study, we used data from a nationwide claims database (1,524,289 individuals without a history of CAD or familial hypercholesterolaemia; 2008-2019). Cox proportional hazards modelling identified the risk of incident CAD by a novel combination of four HDL-C levels, seven LDL-C levels and glucose status.

RESULTS

During the follow-up period (mean: 5.5 years), 8301 (0.99/1000 person-years) events occurred. The risk of CAD increased from lower LDL-C levels accompanied by lower HDL-C levels regardless of the glucose status. Using the most favourable levels of HDL-C and LDL-C (i.e. 60-99 mg/dL and <80 mg/dL, respectively) as references, the hazard ratios (95% confidence interval) for the group with HDL-C levels <40 mg/dL and LDL-C levels <80 mg/dL were 2.74 (1.47-5.11), 2.52 (1.30-4.91) and 2.85 (1.68-4.84) for normoglycaemia, borderline glycaemia and diabetes, respectively. Comparison of the most favourable levels of HDL-C and LDL-C with their least favourable levels (i.e. <40 mg/dL and 180-199 mg/dL, respectively) revealed that the risk of new-onset CAD exhibited a 19-, nine- and seven-fold increase in individuals with normoglycaemia, borderline glycaemia and diabetes, respectively.

CONCLUSIONS

To prevent CAD, LDL-C levels should be strictly controlled in patients with low HDL-C levels regardless of glucose tolerance. Individualized treatment, which involves setting target LDL-C levels based on glucose tolerance and HDL-C values, is required.

Genome-wide discovery and integrative genomic characterization of insulin resistance loci using serum triglycerides to HDL-cholesterol ratio as a proxy

Insulin resistance causes multiple epidemic metabolic diseases, including type 2 diabetes, cardiovascular disease, and fatty liver, but is not routinely measured in epidemiological studies. To discover novel insulin resistance genes in the general population, we conducted genome-wide association studies in 382,129 individuals for triglyceride to HDL-cholesterol ratio (TG/HDL), a surrogate marker of insulin resistance calculable from commonly measured serum lipid profiles. We identified 251 independent loci, of which 62 were more strongly associated with TG/HDL compared to TG or HDL alone, suggesting them as insulin resistance loci. Candidate causal genes at these loci were prioritized by fine mapping with directions-of-effect and tissue specificity annotated through analysis of protein coding and expression quantitative trait variation. Directions-of-effect were corroborated in an independent cohort of individuals with directly measured insulin resistance. We highlight two phospholipase encoding genes, PLA2G12A and PLA2G6, which liberate arachidonic acid and improve insulin sensitivity, and VGLL3, a transcriptional co-factor that increases insulin resistance partially through enhanced adiposity. Finally, we implicate the anti-apoptotic gene TNFAIP8 as a sex-dimorphic insulin resistance factor, which acts by increasing visceral adiposity, specifically in females. In summary, our study identifies several candidate modulators of insulin resistance that have the potential to serve as biomarkers and pharmacological targets.

Biological aging mediates the associations of metabolic score for insulin resistance with all-cause and cardiovascular disease mortality among US adults: A nationwide cohort study

AIM

To investigate the associations of metabolic score for insulin resistance (METS-IR) with all-cause and cardiovascular disease (CVD)-specific mortality and the potential mediating role of biological ageing.

METHODS

A cohort of 19 204 participants from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 was recruited for this study. Cox regression models, restricted cubic splines, and Kaplan-Meier survival curves were used to determine the relationships of METS-IR with all-cause and CVD-specific mortality. Mediation analyses were performed to explore the possible intermediary role of biological ageing markers, including phenotypic age (PhenoAge) and biological age (BioAge).

RESULTS

During a median follow-up of 9.17 years, we observed 2818 deaths, of which 875 were CVD-specific. Multivariable Cox regression showed that the highest METS-IR level (Q4) was associated with increased all-cause (hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.14-1.67) and CVD mortality (HR 1.52, 95% CI 1.10-2.12) compared with the Q1 level. Restricted cubic splines showed a nonlinear relationship between METS-IR and all-cause mortality. Only METS-IR above the threshold (41.02 μg/L) was positively correlated with all-cause death. METS-IR had a linear positive relationship with CVD mortality. In mediation analyses, we found that PhenoAge mediated 51.32% (p < 0.001) and 41.77% (p < 0.001) of the association between METS-IR and all-cause and CVD-specific mortality, respectively. For BioAge, the mediating proportions of PhenoAge were 21.33% (p < 0.001) and 15.88% (p < 0.001), respectively.

CONCLUSIONS

This study highlights the detrimental effects of insulin resistance, as measured by METS-IR, on all-cause and CVD mortality. Moreover, it underscores the role of biological ageing in mediating these associations, emphasizing the need for interventions targeting both insulin resistance and ageing processes to mitigate mortality risks in metabolic disorders.

Association between insulin resistance and vascular damage in an adult population in China: a cross-sectional study

There is a relative scarcity of large-scale population studies investigating the relationship between the insulin resistance index of homeostasis model assessment (HOMA-IR) and vascular damage. Therefore, we assessed the association between HOMA-IR and vascular damage in adults aged 18 years and older in China. A total of 17,985 research subjects were included. Vascular damage markers and relevant laboratory tests were measured. HOMA-IR was calculated as (fasting insulin * fasting blood glucose)/22.5. Vascular damage included arteriosclerosis (ba-PWV > 1800 cm/s), peripheral artery disease (ABI < 0.9), and microalbuminuria (UACR > 30 mg/g). The relationship between HOMA-IR and vascular damage was analyzed using the RCS. The restricted cubic spline (RCS) analysis suggested that HOMA-IR was nonlinearly associated with arteriosclerosis (P for no-liner < 0.01), peripheral artery disease (P for no-liner < 0.01), and microalbuminuria (P for no-liner < 0.01). Further segmented regression analyses revealed that in study subjects with HOMA-IR < 5, we found that HOMA-IR was associated with an increased OR for arteriosclerosis (OR: 1.36, 95% CI (1.28, 1.45), P < 0.01), peripheral artery disease (OR: 1.33, 95% CI (1.10, 1.60), P < 0.01) and microalbuminuria (OR: 1.59, 95% CI (1.49, 1.70), P < 0.01). HOMA-IR is an independent risk factor for vascular damage, both macrovascular and microvascular. The phenomenon of saturation of HOMA-IR with vascular damage needs further investigation.

The association between METS-IR, an indirect index for insulin resistance, and lung cancer risk

BACKGROUND

Insulin resistance has been reported to increase the risk of breast, prostate and colorectal cancer. However, the role of insulin resistance and its interaction with genetic risk in the development of lung cancer remains controversial. Therefore, we aimed to explore the association between a novel metabolic score for insulin resistance (METS-IR) and lung cancer risk.

METHODS

A total of 395 304 participants without previous cancer at baseline were included. The Cox proportional hazards regression model was performed to investigate the association between METS-IR and lung cancer risk. In addition, a Mendelian randomization analysis was also performed to explore the causal relationship. The joint effects and additive interactions between METS-IR and polygenetic risk score (PRS) of lung cancer were also investigated.

RESULTS

During a median follow-up of 11.03 years (Inter-quartile range (IQR): 10.30-11.73), a total of 3161 incident lung cancer cases were diagnosed in 395 304 participants. There was a significant association between METS-IR and lung cancer risk, with an HR of 1.28 (95% CI: 1.17-1.41). Based on the Mendelian randomization analysis, however, no causal associations were observed. We observed a joint effect but no interaction between METS-IR and genetic risk. The lung cancer incidence was estimated to be 100.42 (95% CI: 91.45-109.38) per 100 000 person-year for participants with a high METS-IR and PRS, while only 42.76 (95% CI: 36.94-48.59) with low METS-IR and PRS.

CONCLUSIONS

High METS-IR was significantly associated with an increased risk of lung cancer. Keeping a low level of METS-IR might help reduce the long-term incident risk of lung cancer.

Association between estimated glucose disposal rate and subclinical coronary atherosclerosis

BACKGROUND AND AIMS

The estimated glucose disposal rate (eGDR) is an easily accessible clinical parameter for assessing insulin resistance in patients with diabetes mellitus. In this study, we aimed to investigate the link between eGDR and subclinical coronary atherosclerosis in an asymptomatic middle-aged Korean population.

METHODS AND RESULTS

This study involved 4004 subjects who underwent routine health checkups with coronary multidetector computed tomography (MDCT) at Asan Medical Center from 2007 to 2011, among whom 913 had a follow-up analysis through 2014. The eGDR was calculated using: 21.16 - (0.09 ∗ waist circumference [cm]) - (3.41 ∗ hypertension) - (0.55 ∗ glycated hemoglobin [%]). Patients were categorized into three groups according to the tertiles of eGDR. Subclinical coronary atherosclerosis was defined by significant coronary stenosis (≥50%), presence of plaques, coronary artery calcification (CAC) score, and its progression. As a result, a lower eGDR level was associated with higher prevalence of significant coronary stenosis, plaques, moderate to severe CAC, and CAC progression. Compared to other markers or risk scores, eGDR was superior to other biomarkers of insulin resistance but did not provide additional information beyond classic cardiovascular risk models like the Framingham Risk Score and Pooled Cohort Equations.

CONCLUSION

Decreased eGDR values were significantly associated with higher subclinical coronary atherosclerosis burdens in an asymptomatic middle-aged Korean population. However, its clinical implications remain uncertain due to its weaker performance compared to established cardiovascular risk models.

Assessing the impact of body composition, metabolic and oxidative stress parameters on insulin resistance as a prognostic marker for reactive hypoglycemia: a cross-sectional study in overweight, obese, and normal weight individuals

Oxidative stress (OS) plays a pivotal role in the pathogenesis of insulin resistance (IR), particularly in its association with obesity. This study evaluate both the diagnostic and clinical significance of assessing oxidative status in patients affected by overweight and obesity displaying IR, especially with reactive hypoglycemic episodes (RH). A comprehensive examination of OS biomarkers was carried out, encompassing measurements of total oxidative capacity (TOC) and total antioxidant capacity (TAC). Our analysis results reveal noteworthy connections between OS levels and the severity of IR in overweight and obese patients. Moreover, in the study, we demonstrated the diagnostic utility of serum concentrations of TAC and TOC as indicators of the risk of RH, the occurrence of which, even at the stage of overweight, may be associated with increased OS and further development of obesity. Our findings imply that the evaluation of oxidative status could serve as a crucial diagnostic and prognostic tool for patients observed with IR and overweight and obesity. In conclusion, our study underscores the potential utility of assessing oxidative status in the context of IR and highlights the possibility of identifying novel therapeutic targets for the treatment of overweight and obese patients.

Cardiometabolic Disease Staging and Major Adverse Cardiovascular Event Prediction in 2 Prospective Cohorts

BACKGROUND

Cardiometabolic risk prediction models that incorporate metabolic syndrome traits to predict cardiovascular outcomes may help identify high-risk populations early in the progression of cardiometabolic disease.

OBJECTIVES

The purpose of this study was to examine whether a modified cardiometabolic disease staging (CMDS) system, a validated diabetes prediction model, predicts major adverse cardiovascular events (MACE).

METHODS

We developed a predictive model using data accessible in clinical practice [fasting glucose, blood pressure, body mass index, cholesterol, triglycerides, smoking status, diabetes status, hypertension medication use] from the REGARDS (REasons for Geographic And Racial Differences in Stroke) study to predict MACE [cardiovascular death, nonfatal myocardial infarction, and/or nonfatal stroke]. Predictive performance was assessed using receiver operating characteristic curves, mean squared errors, misclassification, and area under the curve (AUC) statistics.

RESULTS

Among 20,234 REGARDS participants with no history of stroke or myocardial infarction (mean age 64 ± 9.3 years, 58% female, 41% non-Hispanic Black, and 18% diabetes), 2,695 developed incident MACE (13.3%) during a median 10-year follow-up. The CMDS development model in REGARDS for MACE had an AUC of 0.721. Our CMDS model performed similarly to both the ACC/AHA 10-year risk estimate (AUC 0.721 vs 0.716) and the Framingham risk score (AUC 0.673).

CONCLUSIONS

The CMDS predicted the onset of MACE with good predictive ability and performed similarly or better than 2 commonly known cardiovascular disease prediction risk tools. These data underscore the importance of insulin resistance as a cardiovascular disease risk factor and that CMDS can be used to identify individuals at high risk for progression to cardiovascular disease.

METS-IR and all-cause mortality in Korean over 60 years old: Korean genome and epidemiology study-health examinees (KoGES-HEXA) cohorts

Background

The metabolic score for insulin resistance index (METS-IR) is a novel non insulin-based marker that indicates the risk for metabolic syndrome and type 2 diabetes mellitus (T2DM). However, METS-IR has not been investigated in relation to all-cause mortality. We investigated the longitudinal effect of METS-IR on all-cause mortality in a significantly large cohort of Korean adults over 60 years old.

Methods

Data were assessed from 30,164 Korean participants over 60 years of age from the Korean Genome and Epidemiology Study-Health Examinees (KoGES-HEXA) cohort data, linked with the death certificate database of the National Statistical Office. The participants were grouped into three according to METS-IR tertiles. We used multivariate Cox proportional-hazard regression models to prospectively assess hazard ratios (HRs) for all-cause mortality with 95% confidence intervals (CIs) over an 11-year postbaseline period.

Results

During the mean 11.7 years of follow-up, 2,821 individuals expired. The HRs of mortality for METS-IR tertiles were 1.16 (95% CI, 1.01-1.34) in T3 after adjustment for metabolic parameters, but the T2 did not show statistical significance towards increases for incident mortality respectively. In subgroup analysis depending on the cause of mortality, higher METS-IR was associated with cancer mortality (HR, 1.23, 95% CI, 1.01-1.51) but not with cardiovascular mortality (HR, 1.14, 95% CI, 0.83-1.57) after adjustment for the same confounding variables.

Conclusion

The METS-IR may be a useful predictive marker for all-cause mortality and cancer mortality, but not for cardiovascular mortality in subjects over 60 years of age. This implies that early detection and intervention strategies for metabolic syndrome could potentially benefit this identified group.

Association of triglyceride glucose index with cardiovascular events: insights from the Isfahan Cohort Study (ICS)

BACKGROUND

There is limited evidence regarding the evaluation of the association between the triglyceride glucose (TyG) index, an indicator of insulin resistance, and the incident risk of cardiovascular disease (CVD). Therefore, we aimed to examine the relationship between the TyG index and CVD incidence in a cohort of Iranian adults.

METHODS

This study was performed in the framework of the Isfahan Cohort Study (ICS). The study population included 5,432 individuals aged ≥ 35 years. CVD events, including acute myocardial infarction (MI), stroke, and unstable angina (UA), were diagnosed by physicians. The TyG index was calculated as Ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. The relationship between the TyG index and CVD events was investigated using Cox regression models. Receiver operating characteristics (ROC) curve analysis was used to determine the best cut-off for the TyG index for predicting CVD outcomes.

RESULTS

During a median follow-up period of 11.2 years, a total number of 819 CVD, 164 MI, 172 stroke, and 384 UA were recorded. Following adjustment for multiple confounders, elevated TyG levels were associated with a higher risk of CVD (HR = 1.48; 95% CI 1.22-1.79; p < 0.001), MI (HR = 2.24; 95% CI 1.42-3.52; p < 0.001), stroke (HR = 1.45; 95% CI 0.96-2.19; p = 0.042), but not UA (HR = 1.28; 95% CI 0.96-1.69). The optimal TyG index cut-off was 8.91 for predicting CVD (sensitivity 58%; specificity 58%), 9.04 for predicting MI (sensitivity 57%; specificity 65%), 8.92 for predicting stroke (sensitivity 57%; specificity 57%), and 8.98 for predicting UA (sensitivity 53%; specificity 61%).

CONCLUSION

We found a robust, direct association between the TyG index and the incidence of CVD events. This emphasizes the significance of observing the TyG index as an indicator of the occurrence of CVD events.

Insulin resistance is a cardiovascular risk factor in hypertensive adults without type 2 diabetes mellitus

BACKGROUND

Metabolic syndrome refers to the association among several cardiovascular risk factors: obesity, dyslipidemia, hyperglycemia, and hypertension. It is associated with increased cardiovascular risk and the development of type 2 diabetes mellitus. Insulin resistance is the underlying mechanism of metabolic syndrome, although its role in increased cardiovascular risk has not been directly identified.

OBJECTIVE

We investigated the association between insulin resistance and increased cardiovascular risk in hypertensive adults without diabetes mellitus.

DESIGN AND PARTICIPANTS

We enrolled participants without diabetes from an outpatient setting in a retrospective, longitudinal study. Several demographic, clinical, and laboratory parameters were recorded during the observation period. Plasma insulin and homeostatic model assessment for insulin resistance (HOMA-IR) were used to determine insulin resistance and four cardiovascular events (acute coronary disease, acute cerebrovascular disease, incident heart failure, and cardiovascular mortality) were combined into a single outcome. Logistic regression and Cox proportional hazards models were fitted to evaluate the association between covariates and outcomes.

RESULTS

We included 1899 hypertensive adults without diabetes with an average age of 53 years (51.3% women, 23% had prediabetes, and 64.2% had metabolic syndrome). In a logistic regression analysis, male sex (odds ratio, OR = 1.66) having high levels of low-density lipoprotein (LDL, OR = 1.01), kidney function (OR = 0.97), and HOMA-IR (OR = 1.06) were associated with the incidence of cardiovascular events; however, in a survival multivariate analysis, only HOMA-IR (hazard ratio, HR 1.4, 95% confidence interval, CI: 1.05-1.87, p = 0.02) and body mass index (HR 1.05, 95% CI: 1.02-1.08, p = 0.002) were considered independent prognostic variables for the development of incident cardiovascular events.

CONCLUSION

Insulin resistance and obesity are useful for assessing cardiovascular risk in hypertensive people without diabetes but with preserved kidney function. This work demonstrates the predictive value of the measurement of insulin, and therefore of insulin resistance, in an outpatient setting and attending to high-risk patients.

Comparison of seven surrogate insulin resistance indexes for prediction of incident coronary heart disease risk: a 10-year prospective cohort study

Background

There were seven novel and easily accessed insulin resistance (IR) surrogates established, including the Chinese visceral adiposity index (CVAI), the visceral adiposity index (VAI), lipid accumulation product (LAP), triglyceride glucose (TyG) index, TyG-body mass index (TyG-BMI), TyG-waist circumference (TyG-WC) and TyG-waist to height ratio (TyG-WHtR). We aimed to explore the association between the seven IR surrogates and incident coronary heart disease (CHD), and to compare their predictive powers among Chinese population.

Methods

This is a 10-year prospective cohort study conducted in China including 6393 participants without cardiovascular disease (CVD) at baseline. We developed Cox regression analyses to examine the association of IR surrogates with CHD (hazard ratio [HR], 95% confidence intervals [CI]). Moreover, the receiver operating characteristic (ROC) curve was performed to compare the predictive values of these indexes for incident CHD by the areas under the ROC curve (AUC).

Results

During a median follow-up period of 10.25 years, 246 individuals newly developed CHD. Significant associations of the IR surrogates (excepted for VAI) with incident CHD were found in our study after fully adjustment, and the fifth quintile HRs (95% CIs) for incident CHD were respectively 2.055(1.216-3.473), 1.446(0.948-2.205), 1.753(1.099-2.795), 2.013(1.214-3.339), 3.169(1.926-5.214), 2.275(1.391-3.719) and 2.309(1.419-3.759) for CVAI, VAI, LAP, TyG, TyG-BMI, TyG-WC and TyG-WHtR, compared with quintile 1. Furthermore, CVAI showed maximum predictive capacity for CHD among these seven IR surrogates with the largest AUC: 0.632(0.597,0.667).

Conclusion

The seven IR surrogates (excepted for VAI) were independently associated with higher prevalence of CHD, among which CVAI is the most powerful predictor for CHD incidence in Chinese populations.

Adipose tissue homeostasis orchestrates the oxidative, energetic, metabolic and endocrine disruption induced by binge drinking in adolescent rats

Binge drinking (BD) is the most common alcohol consumption model for adolescents, and has recently been related to the generation of high oxidation and insulin resistance (IR). White adipose tissue (WAT) is a target organ for insulin action that regulates whole-body metabolism by secreting adipokines. The present study aimed to analyse the oxidative, inflammatory, energetic and endocrine profile in the WAT of BD-exposed adolescent rats, to obtain an integrative view of insulin secretion and WAT in IR progression. Two groups of male adolescent rats were used: control (n = 8) and BD (n = 8). An intermittent i.p. BD model (20% v/v) was used during 3 consecutive weeks. BD exposure led to a pancreatic oxidative imbalance, which was joint to high insulin secretion by augmenting deacetylase sirtuin-1 (SIRT-1) pancreatic expression and serum adipsin levels. However, BD rats had hyperglycaemia and high homeostasis model assessment of insulin resistance value (HOMA-IR). BD exposure in WAT increased lipid oxidation, as well as decreased insulin receptor substrate 1 (IRS-1) and AKT expression, sterol regulatory element-binding protein 1 (SREBP1), forkhead box O3A (FOXO3a) and peroxisome proliferator-activated receptor γ (PPARγ), and adipocyte size. BD also affected the expression of proteins related to energy balance, such as SIRT-1 and AMP activated protein kinase (AMPK), affecting the adipokine secretion profile (increasing resistin/adiponectin ratio). BD altered the entire serum lipid profile, increasing the concentration of free fatty acids. In conclusion, BD led to an oxidative imbalance and IR process in WAT, which modified the energy balance in this tissue, decreasing the WAT lipogenic/lipolytic ratio, affecting adipokine secretion and the systemic lipid profile, and contributing to the progression of IR. Therefore, WAT is key in the generation of metabolic and endocrine disruption after BD exposure during adolescence in rats. KEY POINTS: Adolescent rat binge drinking (BD) exposure leads to hepatic and systemic oxidative stress (OS) via reactive oxygen species generation, causing hepatic insulin resistance (IR) and altered energy metabolism. In the present study, BD exposure in adolescent rats induces OS in the pancreas, with increased insulin secretion despite hyperglycaemia, indicating a role for IR in white adipose tissue (WAT) homeostasis. In WAT, BD produces IR and an oxidative and energetic imbalance, triggering an intense lipolysis where the serum lipid profile is altered and free fatty acids are increased, consistent with liver lipid accumulation and steatosis. BD exposure heightens inflammation in WAT, elevating pro-inflammatory and reducing anti-inflammatory adipokines, favouring cardiovascular damage. This research provides a comprehensive view of how adolescent BD in rats impacts liver, WAT and pancreas homeostasis, posing a risk for future cardiometabolic complications in adulthood.

The Impact of Testosterone Therapy on Cardiovascular Risk Among Postmenopausal Women

Purpose

To summarize the current state of knowledge surrounding the impact of testosterone therapy on cardiovascular risk factors in postmenopausal women.

Methodology

In this scoping review, a comprehensive search of peer-reviewed literature was conducted in adherence to a methodological framework comprising 4 distinct stages: conceptualizing a comprehensive search strategy, screening relevant publications, extracting pertinent data, and organizing and synthesizing the resultant findings. The search used electronic databases, including MEDLINE, Embase, and Google Scholar, to ensure an exhaustive survey of the available literature.

Results

The database search yielded 150 articles, including systematic reviews, registered trials, and peer-reviewed studies, of which 48 duplicates were removed. Following the title/abstract screening, 36 publications were included in the full-text review. On completion of the full-text review, using the inclusion/exclusion criteria, 29 articles were excluded and 7 remained for data extraction and qualitative synthesis.

Main Conclusion

Existing research provides promising insights into the benefits of low-dose testosterone therapy, typically combined with estrogen therapy. These benefits may include positive impacts on body composition, functional capacity, insulin sensitivity, inflammatory markers, and cholesterol. However, there remains a substantial lack of knowledge surrounding the effects and mechanisms behind testosterone therapy in postmenopausal women in relation to its impacts on cardiovascular risk. High-quality, evidence-based clinical intervention research is needed to investigate testosterone therapy's potential implication on cardiovascular risk factors in post-menopausal women.

Binge drinking leads to an oxidative and metabolic imbalance in skeletal muscle during adolescence in rats: endocrine repercussion

Binge drinking (BD) is an especially pro-oxidant model of alcohol consumption, mainly used by adolescents. It has recently been related to the hepatic IR-process. Skeletal muscle is known to be involved in insulin action and modulation through myokine secretion. However, there is no information on muscle metabolism and myokine secretion after BD exposure in adolescents. Two experimental groups of adolescent rats have been used: control and BD-exposed one. Oxidative balance, energy status and lipid, and protein metabolism have been analyzed in muscle, together with myokine serum levels (IL-6, myostatin, LIF, IL-5, fractalkine, FGF21, irisin, BDNF, FSTL1, apelin, FABP3, osteocrin, osteonectin (SPARC), and oncostatin). In muscle, BD affects the antioxidant enzyme balance leading to lipid and protein oxidation. Besides, it also increases the activation of AMPK and thus contributes to decrease SREBP1 and pmTOR and to increase FOXO3a expressions, promoting lipid and protein degradation. These alterations deeply affect the myokine secretion pattern. This is the first study to examine a general myokine response after exposure to BD. BD not only caused a detrimental imbalance in myokines related to muscle turnover, decreased those contributing to increase IR-process, decreased FST-1 and apelin and their cardioprotective function but also reduced the neuroprotective BDNF. Consequently, BD leads to an important metabolic and energetic disequilibrium in skeletal muscle, which contributes to exacerbate a general IR-process.

Association of triglyceride-glucose index and neutrophil-to-lymphocyte ratio with coronary artery disease

OBJECTIVE

The present study aimed to investigate the association of triglyceride-glucose (TyG) index and neutrophil-to-lymphocyte ratio (NLR) with coronary artery disease (CAD), and evaluate the cumulative value of TyG index and NLR in identifying CAD, as well as the severity of CAD.

METHODS

This retrospective study enrolled 2867 patients who underwent coronary angiography (CAG) for the first time between January 2013 and June 2022 in Zhongnan Hospital of Wuhan University. There were 2109 patients with CAD and 758 patients without CAD. The CAD patients were divided into two groups based on the median of Gensini score (mild stenosis CAD group: Gensini score < 26 points; severe stenosis CAD group: Gensini score ≥ 26 points). To further evaluate the cumulative value of TyG index and NLR in identifying CAD and CAD severity, all patients were classified into four groups based on median of TyG index and NLR: (1) the control group: patients with low-TyG and low-NLR; (2) isolated high-NLR group: patients with low-TyG and high- NLR; (3) isolated high- TyG group: patients with high-TyG and low- NLR; (4) high-TyG combined with high-NLR group: patients with high-TyG and high- NLR.

RESULTS

Multivariate logistic regression analysis showed that both the TyG index and NLR were independent risk factors for CAD, and they were also independent risk factors for severe stenosis in CAD (P < 0.05). Compared with the low-TyG and low- NLR group, patients in high-TyG and high- NLR group had a 1.418 times higher odds ratio (OR) of having CAD and a 1.692 times higher OR of having severe stenosis in CAD in the multivariable logistic regression model. It is worth noting that the OR values of the high-TyG and high- NLR group were higher than those of the isolated high-NLR group and the isolated high- TyG group. The ROC analysis showed that the combination of the TyG index and NLR was superior to TyG index or NLR in predicting CAD and CAD severity.

CONCLUSION

Compared to TyG index or NLR, the combination of the TyG index and NLR is beneficial to improve the diagnostic accuracy of CAD and CAD severity.

Insulin sensitization by hepatic FoxO deletion is insufficient to lower atherosclerosis in mice

Background–

Type 2 diabetes is associated with an increased risk of atherosclerotic cardiovascular disease. It has been suggested that insulin resistance underlies this link, possibly by altering the functions of cells in the artery wall. We aimed to test whether improving systemic insulin sensitivity reduces atherosclerosis.

Methods–

We used mice that are established to have improved systemic insulin sensitivity: those lacking FoxO transcription factors in hepatocytes. Three hepatic FoxO isoforms (FoxO1, FoxO3, and FoxO4) function together to promote hepatic glucose output, and ablating them lowers glucose production, lowers circulating glucose and insulin, and improves systemic insulin sensitivity. We made these mice susceptible to atherosclerosis in two different ways, by injecting them with gain-of-function AAV8.mPcsk9D377Y and by crossing with Ldlr-/- mice.

Results–

We verified that hepatic FoxO ablation improves systemic insulin sensitivity in these atherosclerotic settings. We observed that FoxO deficiency caused no reductions in atherosclerosis, and in some cases increased atherosclerosis. These phenotypes coincided with large increases in circulating triglycerides in FoxO-ablated mice.

Conclusions–

These findings suggest that systemic insulin sensitization is insufficient to reduce atherosclerosis.

Association of triglyceride-glucose index with coronary severity and mortality in patients on dialysis with coronary artery disease

BACKGROUND

The triglyceride-glucose (TyG) index is validated as a reliable biomarker of insulin resistance and an independent predictor of cardiovascular prognosis. However, the prognostic value of the TyG index in patients on dialysis with coronary artery disease (CAD) remained unexplored. This study aimed to determine the association between the TyG index and CAD severity and mortality in these patients.

METHODS

A total of 1061 dialysis patients with CAD were enrolled in this multi-center cohort study from January 2015 to June 2021. The extent and severity of CAD were evaluated using the multivessel disease and Gensini score (GS). Patients were followed up for all-cause death and cardiovascular death.

RESULTS

The multivariable logistic regression model indicated that the TyG index was significantly associated with multivessel disease (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.18-1.94, P = 0.001), and high GS (OR 1.33, 95% CI 1.10-1.61, P = 0.003). After adjusting for baseline risk factors, the hazards of all-cause death and cardiovascular death were 1.23 (95% CI 1.06-1.43, P = 0.007), and 1.33 (95% CI 1.11-1.59, P = 0.002), independent of CAD severity. Restricted cubic spline analysis identified a dose-response association between the TyG index and both CAD severity and mortality (all P for nonlinearity > 0.05). When modeling the TyG index as a categorical variable, these independent associations remained. Subgroup analyses did not substantially modify the results. Furthermore, incorporating the TyG index into the existing risk prediction model improved the predictive accuracy for all-cause death and cardiovascular death, as evaluated by C-statistic, continuous net reclassification improvement, and integrated discrimination improvement.

CONCLUSIONS

In patients on dialysis with CAD, the TyG index was significantly associated with more severe CAD as well as mortality. These results highlight the clinical importance of the TyG index for assessing CAD severity and risk stratification in patients on dialysis with CAD.

Insulin and aging - a disappointing relationship

Experimental studies in animal models of aging such as nematodes, fruit flies or mice have observed that decreased levels of insulin or insulin signaling promotes longevity. In humans, hyperinsulinemia and concomitant insulin resistance are associated with an elevated risk of age-related diseases suggestive of a shortened healthspan. Age-related disorders include neurodegenerative diseases, hypertension, cardiovascular disease, and type 2 diabetes. High ambient insulin concentrations promote increased lipogenesis and fat storage, heightened protein synthesis and accumulation of non-functional polypeptides due to limited turnover capacity. Moreover, there is impaired autophagy activity, and less endothelial NO synthase activity. These changes are associated with mitochondrial dysfunction and oxidative stress. The cellular stress induced by anabolic activity of insulin initiates an adaptive response aiming at maintaining homeostasis, characterized by activation of the transcription factor Nrf2, of AMP activated kinase, and an unfolded protein response. This protective response is more potent in the long-lived human species than in short-lived models of aging research resulting in a stronger pro-aging impact of insulin in nematodes and fruit flies. In humans, resistance to insulin-induced cell stress decreases with age, because of an increase of insulin and insulin resistance levels but less Nrf2 activation. These detrimental changes might be contained by adopting a lifestyle that promotes low insulin/insulin resistance levels and enhances an adaptive response to cellular stress, as observed with dietary restriction or exercise.

Daytime napping and coronary heart disease risk in adults: a systematic review and dose-response meta-analysis

PURPOSE

The present study investigated the association between daytime napping and coronary heart disease (CHD) risk among adults.

METHODS

Articles were detected by using PubMed, ISI Web of Science, and Scopus databases until November 8th, 2021. The relevant data were found among the eight included articles and were pooled for meta-analysis in adult participants via a random-effects model.

RESULTS

Among 167,025 adults, the results revealed that daytime napping was associated with an enhanced risk of CHD (risk ratios [RR] = 1.30; 95% CI: 1.06, 1.60; p < 0.001). Subgroup analysis by daytime napping duration also indicated that daytime napping for at least 1 h had three times higher influence on the enhanced risk of CHD (RR = 1.34; 95% CI: 1.14, 1.58; p < 0.001) than that of daytime napping for less than 1 h (RR = 1.10; 95% CI: 1.02, 1.19; p = 0.014). In addition, subgroup analysis by region illustrated that daytime napping was linked with an enhanced risk of CHD in Chinese (RR = 1.41; 95% CI: 1.19, 1.66; p < 0.001), but not in European or American populations. Furthermore, the subgroup analysis of napping duration and risk of CHD suggested that their relation was significant just in those studies that controlled for depressive symptoms (RR = 1.52; 95% CI: 1.29, 1.80; p < 0.001, n = 3) and night sleep duration (RR = 1.42; 95% CI: 1.21, 1.66; p < 0.001, n = 5). The linear dose-response meta-analysis revealed that each 15-min increase in daytime napping was related with a 5% higher risk of CHD (RR = 1.05; 95% CI: 1.02, 1.08; I2 = 58.7%; p < 0.001). Furthermore, nonlinear dose-response meta-analysis revealed a positive linear relationship between daytime napping and CHD risk in adults (p nonlinearity = 0.484, p dose-response = 0.003).

CONCLUSION

Results showed that daytime napping was related with an increased risk of CHD in adults. The evidence from this study suggests that the public should be made conscious of the adverse outcomes of long daytime napping for CHD, notably among the Chinese population. Additional studies are required to confirm potential links between CHD risk and daytime napping.

Independent and joint associations between the triglyceride-glucose index and NT-proBNP with the risk of adverse cardiovascular events in patients with diabetes and acute coronary syndrome: a prospective cohort study

BACKGROUND

Elevated triglyceride-glucose (TyG) index and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are independently associated with increased risk of major adverse cardio-cerebral events (MACCEs) in diabetic patients with the acute coronary syndrome (ACS), but have not been evaluated jointly. We sought to investigate the independent and joint association of the TyG index and NT-proBNP with MACCEs risk.

METHODS

Data from 5046 patients with diabetes and ACS were recorded in the Cardiovascular Center Beijing Friendship Hospital Database Bank between 2013 and 2021, including measurements of fasting triglycerides, plasma glucose, and NT-proBNP. The TyG index was calculated as Ln (fasting triglycerides [mg/dL] × fasting plasma glucose [mg/dL]/2). Associations of the TyG index and NT-proBNP with MACCEs risk were assessed using flexible parametric survival models.

RESULTS

During 13589.9 person-years of follow-up, 985 incident MACCEs of the 5046 patients (65.6 years of age and 62.0% men) were observed. Elevated TyG index (HR: 1.18; 95% CI 1.05‒1.32 per 1 unit increase) and NT-proBNP categories (HR: 1.95; 95% CI: 1.50‒2.54 for > 729 pg/ml compared to < 129 pg/ml) were independently associated with MACCEs risk in the fully adjusted model. According to the joint categories of the TyG index and NT-proBNP, patients with the TyG index > 9.336 and NT-proBNP > 729 pg/ml were at the highest risk of MACCEs (HR: 2.45; 95% CI 1.64‒3.65) than the ones with TyG index < 8.746 and NT-proBNP < 129 pg/ml. The test for interaction was not significant (P _interaction = 0.49). Incorporating these two biomarkers into the established clinical model, the Global Registry of Acute Coronary Events (GRACE) risk score, resulted in a significant improvement in risk stratification.

CONCLUSIONS

The TyG index and NT-proBNP were independently and jointly associated with the risk of MACCEs in patients with diabetes and ACS, suggesting that patients with both markers elevated should be aware of the higher risk in the future.

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 between triglyceride to high-density lipoprotein cholesterol ratio and type 2 diabetes risk in Japanese

Abnormal lipid metabolism is known to increases the risk for metabolic diseases, such as type 2 diabetes mellitus(T2DM). The relationship between baseline ratio of triglyceride to HDL cholesterol (TG/HDL-C) and T2DM in Japanese adults was investigated in this study. Our secondary analysis included 8419 male and 7034 female Japanese subjects who were free of diabetes at baseline. The correlation between baseline TG/HDL-C and T2DM was analyzed by a proportional risk regression model, the nonlinear correlation between baseline TG/HDL-C and T2DM was analyzed by a generalized additive model (GAM), and the threshold effect analysis was performed by a segmented regression model. We conducted subgroup analyses in different populations. During the median 5.39 years follow-up, 373 participants, 286 males and 87 females, developed diabetes mellitus. After full adjustment for confounders, the baseline TG/HDL-C ratio positively correlated with the risk of diabetes (hazard ratio 1.19, 95% confidence interval 1.09-1.3), and smoothed curve fitting and two-stage linear regression analysis revealed a J-shaped relationship between baseline TG/HDL-C and T2DM. The inflection point for baseline TG/HDL-C was 0.35. baseline TG/HDL-C > 0.35 was positively associated with the development of T2DM (hazard ratio 1.2, 95% confidence interval 1.10-1.31). Subgroup analysis showed no significant differences in the effect between TG/HDL-C and T2DM in different populations. A J-shaped relationship was observed between baseline TG/HDL-C and T2DM risk in the Japanese population. When TG/HDL-C was higher than 0.35, there was a positive relationship between baseline TG/HDL-C and the incidence of diabetes mellitus.

Association Between Premorbid Metabolic Syndrome and Coronary Arterial Stenosis: Results from One Medical Center in Taiwan

Background: Although the relationship between metabolic syndrome (MetS) and cardiovascular disease is already well-established, there is limited evidence as to whether individuals are at risk for cardiovascular disease during the premorbid state of MetS. The aim of this study is to explore the relationship between coronary arterial stenosis and MetS in a nonhypertensive and nondiabetic population. Methods: In this cross-sectional study, we analyzed the data of participants who underwent annual health checkups in a medical center. These data were collected from physical examination, blood tests, cardiac computed tomography examinations, and medical charts. We excluded those with established hypertension or diabetes and age of <50 or >75 years. Results: This study recruited 700 participants with a mean age of 59.5 years. More than 31% had MetS, and the overall prevalence of coronary arterial stenosis was 48.0% (grade 1, 2, 3, 4: 16.3%, 20.9%, 8.4%, 2.4%, respectively). In univariate analysis, older age, male sex, smoking, body mass index, elevated fasting plasma glucose (FPG), elevated triglyceride, lower level of high-density lipoprotein cholesterol, and presence of MetS were all positively correlated with coronary arterial stenosis. After adjustment for confounding factors, MetS still showed strong association with high grades of coronary arterial stenosis [odds ratio (OR) 2.86, confidence interval (95% CI) 1.30-4.01]. Specific components of MetS, such as elevated triglyceride [OR 2.02, 95% CI 1.14-3.57] and elevated FPG [OR 2.25, 95% CI 1.31-3.88], were also associated with coronary arterial stenosis. Conclusion: Our study concluded that premorbid MetS was significantly associated with coronary arterial stenosis. As for the individual components, elevated triglyceride and elevated FPG were both correlated with coronary arterial stenosis. Early preventive measures would be suggested at this stage of MetS to prevent future cardiovascular events.

Association of the triglyceride glucose index as a measure of insulin resistance with mortality and cardiovascular disease in populations from five continents (PURE study): a prospective cohort study

BACKGROUND

The triglyceride glucose (TyG) index is an easily accessible surrogate marker of insulin resistance, an important pathway in the development of type 2 diabetes and cardiovascular diseases. However, the association of the TyG index with cardiovascular diseases and mortality has mainly been investigated in Asia, with few data available from other regions of the world. We assessed the association of insulin resistance (as determined by the TyG index) with mortality and cardiovascular diseases in individuals from five continents at different levels of economic development, living in urban or rural areas. We also examined whether the associations differed according to the country's economical development.

METHODS

We used the TyG index as a surrogate measure for insulin resistance. Fasting triglycerides and fasting plasma glucose were measured at the baseline visit in 141 243 individuals aged 35-70 years from 22 countries in the Prospective Urban Rural Epidemiology (PURE) study. The TyG index was calculated as Ln (fasting triglycerides [mg/dL] x fasting plasma glucose [mg/dL]/2). We calculated hazard ratios (HRs) using a multivariable Cox frailty model with random effects to test the associations between the TyG index and risk of cardiovascular diseases and mortality. The primary outcome of this analysis was the composite of mortality or major cardiovascular events (defined as death from cardiovascular causes, and non-fatal myocardial infarction, or stroke). Secondary outcomes were non-cardiovascular mortality, cardiovascular mortality, all myocardial infarctions, stroke, and incident diabetes. We also did subgroup analyses to examine the magnitude of associations between insulin resistance (ie, the TyG index) and outcome events according to the income level of the countries.

FINDINGS

During a median follow-up of 13·2 years (IQR 11·9-14·6), we recorded 6345 composite cardiovascular diseases events, 2030 cardiovascular deaths, 3038 cases of myocardial infarction, 3291 cases of stroke, and 5191 incident cases of type 2 diabetes. After adjusting for all other variables, the risk of developing cardiovascular diseases increased across tertiles of the baseline TyG index. Compared with the lowest tertile of the TyG index, the highest tertile (tertile 3) was associated with a greater incidence of the composite outcome (HR 1·21; 95% CI 1·13-1·30), myocardial infarction (1·24; 1·12-1·38), stroke (1·16; 1·05-1·28), and incident type 2 diabetes (1·99; 1·82-2·16). No significant association of the TyG index was seen with non-cardiovascular mortality. In low-income countries (LICs) and middle-income countries (MICs), the highest tertile of the TyG index was associated with increased hazards for the composite outcome (LICs: HR 1·31; 95% CI 1·12-1·54; MICs: 1·20; 1·11-1·31; p_interaction=0·01), cardiovascular mortality (LICs: 1·44; 1·15-1·80; p_interaction=0·01), myocardial infarction (LICs: 1·29; 1·06-1·56; MICs: 1·26; 1·10-1·45; p_interaction=0·08), stroke (LICs: 1·35; 1·02-1·78; MICs: 1·17; 1·05-1·30; p_interaction=0·19), and incident diabetes (LICs: 1·64; 1·38-1·94; MICs: 2·68; 2·40-2·99; p_interaction <0·0001). In contrast, in high-income countries, higher TyG index tertiles were only associated with an increased hazard of incident diabetes (2·95; 2·25-3·87; p_interaction <0·0001), but not of cardiovascular diseases or mortality.

INTERPRETATION

The TyG index is significantly associated with future cardiovascular mortality, myocardial infarction, stroke, and type 2 diabetes, suggesting that insulin resistance plays a promoting role in the pathogenesis of cardiovascular and metabolic diseases. Potentially, the association between the TyG index and the higher risk of cardiovascular diseases and type 2 diabetes in LICs and MICs might be explained by an increased vulnerability of these populations to the presence of insulin resistance.

FUNDING

Full funding sources are listed at the end of the paper (see Acknowledgments).

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

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.

Can low-carbohydrate diets be recommended for reducing cardiovascular risk?

PURPOSE OF REVIEW

This review provides a rationale for implementing carbohydrate restriction as a dietary therapy to improve biomarkers of cardiovascular health and suggests that this will require a paradigm shift away from what is currently promulgated as a 'heart-healthy' diet.

RECENT FINDINGS

Type 2 diabetes mellitus (T2DM), metabolic syndrome, and related co-morbidities are major risk factors for cardiovascular disease (CVD). Ideally, then, a diet intended to support cardiovascular health should be one that improves or reverses these underlying risk factors. Carbohydrate restriction is effective for this purpose as well as for favorably impacting atherogenic dyslipidemia. Recent consensus reports from select national organizations have endorsed low-carbohydrate diets for improving glycemia and cardiovascular risk. Reluctance among public health organizations and some clinicians to more widely promote this therapeutic nutritional approach is driven primarily by the increase in serum low-density lipoprotein cholesterol (LDL-C) observed in a proportion of individuals who adopt a low-carbohydrate diet. Here we explore the rationale for using carbohydrate restriction to improve cardiovascular health by way of favorably impacting T2DM and insulin resistance, and why this salutary effect outweighs the potential adverse effects of an increase in serum LDL-C.

SUMMARY

Carbohydrate restriction is a logical foundation for a dietary intervention intended to reduce CVD risk, particularly among individuals with T2DM or metabolic syndrome.

Association Between Insulin Resistance and Cardiovascular Disease Risk Varies According to Glucose Tolerance Status: A Nationwide Prospective Cohort Study

OBJECTIVE

To investigate whether the association between insulin resistance and cardiovascular disease (CVD) differs by glucose tolerance status.

RESEARCH DESIGN AND METHODS

We analyzed a nationwide sample of 111,576 adults without CVD at baseline, using data from the China Cardiometabolic Disease and Cancer Cohort Study. Insulin resistance was estimated by sex-specific HOMA of insulin resistance (HOMA-IR) quartiles for participants with normal glucose tolerance, prediabetes, or diabetes, separately, and by 1 SD of HOMA-IR for the overall study participants. We used Cox proportional hazards models to examine the association between insulin resistance and incident CVD according to glucose tolerance status and evaluate the CVD risk associated with the combined categories of insulin resistance and obesity in prediabetes and diabetes, as compared with normal glucose tolerance. Models were adjusted for age, sex, education attainment, alcohol drinking, smoking, physical activity, and diet quality.

RESULTS

In participants with normal glucose tolerance, prediabetes, and diabetes defined by three glucose parameters, multivariable-adjusted hazard ratios (95% CIs) for incident CVD associated with the highest versus the lowest quartile of HOMA-IR were 1.03 (0.82-1.30), 1.23 (1.07-1.42), and 1.61 (1.30-2.00), respectively; the corresponding values for CVD per 1-SD increase in HOMA-IR were 1.04 (0.92-1.18), 1.12 (1.06-1.18), and 1.15 (1.09-1.21), respectively (P for interaction = 0.011). Compared with participants with normal glucose tolerance, in participants with prediabetes, the combination of the highest HOMA-IR quartile and obesity showed 17% (95% CI 2-34%) higher risk of CVD, while the combination of the lowest two HOMA-IR quartiles and nonobesity showed 15-17% lower risk of CVD. In participants with diabetes, the upper two HOMA-IR quartiles exhibited 44-77% higher risk of CVD, regardless of obesity status. Consistent findings were observed for glucose tolerance status defined by different combinations of glycemic parameters.

CONCLUSIONS

Glucose intolerance status exacerbated the association between insulin resistance and CVD risk. Compared with adults with normal glucose tolerance, adults with prediabetes who were both insulin resistant and obese exhibited higher risks of CVD, while in adults with diabetes, the CVD risk related to insulin resistance remained, regardless of obesity.

Separating the direct effects of traits on atherosclerotic cardiovascular disease from those mediated by type 2 diabetes

AIMS/HYPOTHESIS

Type 2 diabetes and atherosclerotic CVD share many risk factors. This study aimed to systematically assess a broad range of continuous traits to separate their direct effects on coronary and peripheral artery disease from those mediated by type 2 diabetes.

METHODS

Our main analysis was a two-step Mendelian randomisation for mediation to quantify the extent to which the associations observed between continuous traits and liability to atherosclerotic CVD were mediated by liability to type 2 diabetes. To support this analysis, we performed several univariate Mendelian randomisation analyses to examine the associations between our continuous traits, liability to type 2 diabetes and liability to atherosclerotic CVD.

RESULTS

Eight traits were eligible for the two-step Mendelian randomisation with liability to coronary artery disease as the outcome and we found similar direct and total effects in most cases. Exceptions included fasting insulin and hip circumference where the proportion mediated by liability to type 2 diabetes was estimated as 56% and 52%, respectively. Six traits were eligible for the analysis with liability to peripheral artery disease as the outcome. Again, we found limited evidence to support mediation by liability to type 2 diabetes for all traits apart from fasting insulin (proportion mediated: 70%).

CONCLUSIONS/INTERPRETATION

Most traits were found to affect liability to atherosclerotic CVD independently of their relationship with liability to type 2 diabetes. These traits are therefore important for understanding atherosclerotic CVD risk regardless of an individual's liability to type 2 diabetes.

Biochemical mechanism underlying the pathogenesis of diabetic retinopathy and other diabetic complications in humans: the methanol-formaldehyde-formic acid hypothesis

Hyperglycemia in diabetic patients is associated with abnormally-elevated cellular glucose levels. It is hypothesized that increased cellular glucose will lead to increased formation of endogenous methanol and/or formaldehyde, both of which are then metabolically converted to formic acid. These one-carbon metabolites are known to be present naturally in humans, and their levels are increased under diabetic conditions. Mechanistically, while formaldehyde is a cross-linking agent capable of causing extensive cytotoxicity, formic acid is an inhibitor of mitochondrial cytochrome oxidase, capable of inducing histotoxic hypoxia, ATP deficiency and cytotoxicity. Chronic increase in the production and accumulation of these toxic one-carbon metabolites in diabetic patients can drive the pathogenesis of ocular as well as other diabetic complications. This hypothesis is supported by a large body of experimental and clinical observations scattered in the literature. For instance, methanol is known to have organ- and species-selective toxicities, including the characteristic ocular lesions commonly seen in humans and non-human primates, but not in rodents. Similarly, some of the diabetic complications (such as ocular lesions) also have a characteristic species-selective pattern, closely resembling methanol intoxication. Moreover, while alcohol consumption or combined use of folic acid plus vitamin B is beneficial for mitigating acute methanol toxicity in humans, their use also improves the outcomes of diabetic complications. In addition, there is also a large body of evidence from biochemical and cellular studies. Together, there is considerable experimental support for the proposed hypothesis that increased metabolic formation of toxic one-carbon metabolites in diabetic patients contributes importantly to the development of various clinical complications.

Insulin Resistance Is Cheerfully Hitched with Hypertension

Cardiovascular diseases and type 2 diabetes mellitus (T2DM) have risen steadily worldwide, particularly in low-income and developing countries. In the last hundred years, deaths caused by cardiovascular diseases increased rapidly to 35-40%, becoming the most common cause of mortality worldwide. Cardiovascular disease is the leading cause of morbidity and mortality in type 2 diabetes mellitus (T2DM), which is aggravated by hypertension. Hypertension and diabetes are closely interlinked since they have similar risk factors such as endothelial dysfunction, vascular inflammation, arterial remodeling, atherosclerosis, dyslipidemia, and obesity. Patients with high blood pressure often show insulin resistance and have a higher risk of developing diabetes than normotensive individuals. It has been observed that over the last 30 years, the prevalence of insulin resistance (IR) has increased significantly. Accordingly, hypertension and insulin resistance are strongly related to an increased risk of impaired glucose tolerance, diabetes, cardiovascular diseases (CVD), and endocrine disorders. Common mechanisms, for instance, upregulation of the renin-angiotensin-aldosterone system, oxidative stress, inflammation, and activation of the immune system, possibly have a role in the association between diabetes and hypertension. Altogether these abnormalities significantly increase the risk of developing type 2 diabetes.

Triglyceride-Glucose Index and New-Onset Atrial Fibrillation in ST-Segment Elevation Myocardial Infarction Patients After Percutaneous Coronary Intervention

Background

New-onset atrial fibrillation (NOAF) is associated with worse prognostic outcomes in cases diagnosed with ST-segment elevation myocardial infarction (STEMI) patients after percutaneous coronary intervention (PCI). The triglyceride-glucose (TyG) index, as a credible and convenient marker of insulin resistance, has been shown to be predictive of outcomes for STEMI patients following revascularization. The association between TyG index and NOAF among STEMI patients following PCI, however, has not been established to date.

Objective

To assess the utility of the TyG index as a predictor of NOAF incidence in STEMI patients following PCI, and to assess the relationship between NOAF and long-term all-cause mortality.

Methods

This retrospective cohort research enrolled 549 STEMI patients that had undergone PCI, with these patients being clustered into the NOAF group and sinus rhythm (SR) group. The predictive relevance of TyG index was evaluated through logistic regression analyses and the receiver operating characteristic (ROC) curve. Kaplan-Meier curve was employed to explore differences in the long-term all-cause mortality between the NOAF and SR group.

Results

NOAF occurred in 7.7% of the enrolled STEMI patients after PCI. After multivariate logistic regression analysis, the TyG index was found to be an independent predictor of NOAF [odds ratio (OR): 8.884, 95% confidence interval (CI): 1.570–50.265, P = 0.014], with ROC curve analyses further supporting the predictive value of this parameter, which exhibited an area under ROC curve of 0.758 (95% CI: 0.720–0.793, P < 0.001). All-cause mortality rates were greater for patients in the NOAF group in comparison with the SR group over a median 35-month follow-up period (log-rank P = 0.002).

Conclusions

The TyG index exhibits values as an independent predictor of NOAF during hospitalization, which indicated a poorer prognosis after a relatively long-term follow-up.

Chronic Kidney Disease, Metabolic Syndrome and Cardiovascular Risk: Insights and Associated Mechanistic Pathways

Abstract:

This study is a narrative review that aims to address the conceptual, characteristic, pathophysiological, and mechanistic aspects that define the profile of metabolic syndrome and chronic kidney disease. The objective was to investigate current knowledge and elucidate, through discussions on the topic, the main interrelated paths. This review was carried out unsystematically, from March to May 2020, by means of a survey of the literature indexed in the PubMed, Web of Science, and Scopus (Elsevier®) databases. The scientific materials collected showed that the cross-talk between the diseases in question is mainly based on the conditions of resistance to insulin action, endothelial dysfunction, activation pathways of the Renin-Angiotensin-Aldosterone system and adipokine imbalance, also emphasizing the influence of atherosclerotic events in kidney damage. Furthermore, it was reinforced the fact that inflammatory processes play an important role in the worsening and evolution of the clinical condition of patients, especially when they have underlying pathologies chronically treated for subclinical inflammation. It is expected that a greater number of original researches will propose to investigate other possible interactions, with a view to standardized treatment of these diseases or nutritional management.

Association between new markers of cardiovascular risk and hepatic insulin resistance in those at high risk of developing type 2 diabetes

AIM/HYPOTHESIS

Hepatic insulin resistance (HIR) is considered to be an independent predictor of metabolic disorders and plays an important role in systemic inflammation, which contributes to abnormalities in cardiovascular disease (CVD) risk factors. The aim of this study was to investigate the relationship between HIR and new markers of cardiovascular risks, including leptin/adiponectin ratio (L/A), lipoprotein(a) [Lp(a)], and tumor necrosis factor alpha (TNF-α), at comparable whole body insulin sensitivity in non-diabetic individuals with or without CVD and at high risk of developing type 2 diabetes.

METHODS

The HIR index, L/A, Lp(a), and TNF-α were measured in 50 participants with CVD and in 200 without CVD (1:4 ratio). These were also matched for the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda-insulin sensitivity index (ISI) in an observational study design.

RESULTS

The HIR index (1.52 ± 0.14 vs. 1.45 ± 0.17, p < 0.02), L/A (3.22 ± 3.10 vs. 2.09 ± 2.27, p < 0.004), and levels of Lp(a) (66.6 ± 49.5 vs. 37.9 ± 3 6.8 mg/dL, p < 0.0001) and TNF-α (18.9 ± 21.8 vs. 5.4 ± 7.1 pg/mL, p < 0.0001) were higher in those with CVD than those without CVD. HOMA-IR and ISI were not significantly different (p = 0.88 and p = 0.35, respectively). The HIR index was directly correlated with L/A (r = 0.41, p < 0.0001), Lp(a) (r = 0.20, p < 0.002), TNF- α (r = 0.14, p < 0.03), and diastolic blood pressure (DBP) (r = 0.13, p < 0.03). The stepwise model analysis showed that L/A, Lp(a), and TNF-α explained about 20% of the variation in the HIR indices of all the participants (p < 0.02).

CONCLUSIONS/INTERPRETATIONS

Our results suggest a positive association between HIR and new markers of cardiovascular risk [L/A, Lp(a), and TNF- α] at comparable whole body insulin sensitivity in those with or without CVD and at high risk of developing type 2 diabetes.

Network Pharmacology and Molecular Docking-Based Analysis on Bioactive Anticoronary Heart Disease Compounds in Trichosanthes kirilowii Maxim and Bulbus allii Macrostemi

Trichosanthes kirilowii Maxim. and Bulbus allii Macrostemi are the components of Gualou Xiebai decoction (GLXB), a commonly used herbal combination for the treatment of coronary heart disease (CHD) in traditional Chinese medicine. Although GLXB is associated with a good clinical effect, its active compounds and mechanism of action remain unclear, which limits its clinical application and the development of novel drugs. In this study, we explored key compounds, targets, and mechanisms of action for GLXB in the treatment of CHD using the network pharmacology approach. We identified 18 compounds and 21 action targets via database screening. Enrichment analysis indicated that the effects of GLXB in patients with CHD are primarily associated with the regulation of signalling pathways for tumour necrosis factor, nuclear factor-kappa B, hypoxia-inducible factor-1, arachidonic acid metabolism, and insulin resistance. GLXB thus exerts anti-inflammatory, antihypoxic, and antiagglutinating effects; regulates lipid metabolism; and combats insulin resistance in CHD via these pathways, respectively. After reverse targeting, we observed that the main active compounds of GLXB in the treatment of CHD were quercetin, naringenin, β-sitosterol, ethyl linolenate, ethyl linoleate, and prostaglandin B1. To explore the potential of these compounds in the treatment of CHD, we verified the affinity of the compounds and targets via molecular docking analysis. Our study provides a bridge for the transformation of natural herbs and molecular compounds into novel drug therapies for CHD.

The association between triglyceride-glucose index and major adverse cardiovascular events in patients with acute coronary syndrome - dose-response meta-analysis

BACKGROUND AND AIMS

Triglyceride-Glucose (TyG) index is an accurate biomarker of insulin resistance, which is potentially associated with adverse cardiovascular events. We aimed to assess the dose-response relationship between Triglyceride-Glucose (TyG) Index and Major Adverse Cardiovascular Events (MACE) in patients with Acute Coronary Syndrome (ACS).

METHODS AND RESULTS

A systematic literature search was performed using PubMed, Scopus, and Embase for records published from the inception up until 7 February 2021. Studies that fulfilled all of these criteria were included: 1) prospective or retrospective observational studies reporting patients with ACS and 2) assessing the impact of TyG index on MACE with at least three quantitative classifications. The outcome of interest is MACE across the TyG index intervals. MACE was a composite of all-cause mortality, myocardial infarction, unstable angina pectoris, target vessel revascularization, cerebrovascular accidents, and heart failure. The effect estimates were reported as relative risks (RRs). There are 13,684 subjects from 4 studies included in this meta-analysis. This meta-analysis showed that the highest category of TyG index was associated with twofold MACE (RR 2.09 [1.59, 2.76], p < 0.001; I²: 68.4%, p = 0.02) compared to the lowest category in patients with ACS. Dose-response meta-analysis showed that the relationship between TyG index and MACE was non-linear (p < 0.001), with statistical significance reached around TyG index 8.9 and increased non-linearly. The dose-response curve became significantly steeper after TyG index of 9.1-9.2.

CONCLUSION

TyG index was associated with MACE in patients with ACS in a non-linear fashion.

PROSPERO

CRD42021235765.

Impact of triglyceride-glucose index on long-term cardiovascular outcomes in patients with myocardial infarction with nonobstructive coronary arteries

BACKGROUND AND AIMS

Triglyceride-glucose (TyG) index has been reported as a novel surrogate marker of insulin resistance and a risk factor in patients with coronary artery disease. We aimed to investigate the prognostic value of TyG index in a distinct entity with myocardial infarction with nonobstructive coronary arteries (MINOCA).

METHODS AND RESULTS

A total of 1179 MINOCA patients were recruited and divided according to tertile levels of TyG index. The primary endpoint was a composite of major adverse cardiovascular events (MACE), including all-cause death, reinfarction, stroke, revascularization and hospitalization for unstable angina or heart failure. Kaplan-Meier, Cox regression and receiver-operating characteristic analyses were performed. Patients with higher tertiles of TyG index had a significantly higher incidence of MACE (9.6%, 14.9%, 18.0%; p = 0.003) over the median follow-up of 41.7 months. After multivariate adjustment, elevated TyG index was significantly associated with an increased risk of MACE (HR 1.33, 95% CI: 1.04-1.69, p = 0.020). The adjusted risk of MACE also increased with rising tertiles of TyG index (tertile 1 as reference; tertile 2: HR 1.64, 95% CI: 1.06-2.53, p = 0.025; tertile 3: HR 1.85, 95% CI: 1.17-2.93, p = 0.008). The TyG index remained a robust risk factor in overall and subgroups of MINOCA patients (all p < 0.05). Moreover, the TyG index yielded a moderate predictive value of MACE (area under the curve 0.66, 95% CI:0.61-0.71, p < 0.001).

CONCLUSION

Elevated TyG index was independently associated with a poor prognosis after MINOCA. Routine assessment of TyG index may improve risk stratification and facilitate decision making in MINOCA patients.

Positive association between the ratio of triglycerides to high-density lipoprotein cholesterol and diabetes incidence in Korean adults

BACKGROUND

Insulin resistance is associated with the incidence of diabetes and cardiovascular diseases such as myocardial infarction. The ratio of triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) (TG/HDL-C ratio) is positively correlated with insulin resistance. This study aimed to investigate the relationship between the TG/HDL-C ratio and the incidence of diabetes in Korean adults.

METHODS

This retrospective study used data from the National Health Insurance Service-National Health Screening Cohort. The TG/HDL-C ratio was divided into three tertiles, the T₁, T₂, and T₃ groups, based on sex. We estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) for diabetes using multivariate Cox proportional hazards regression analyses.

RESULTS

A total of 80,693 subjects aged between 40 and 79 years were enrolled. The median follow-up period was 5.9 years. The estimated cumulative incidence of diabetes in the T₁, T₂, and T₃ groups was 5.94%, 8.23%, and 13.50%, respectively, in men and 4.12%, 4.72%, and 6.85%, respectively, in women. Compared to T₁, the fully adjusted HRs (95% CIs) of the T₂ and T₃ groups for new-onset diabetes were 1.17 (1.06-1.30) and 1.47 (1.34-1.62), respectively, in men and 1.20 (1.02-1.42) and 1.52 (1.30-1.78), respectively, in women.

CONCLUSIONS

Increased TG/HDL-C ratio was significantly associated with a higher risk of new-onset diabetes in both sexes.

Hiding unhealthy heart outcomes in a low-fat diet trial: the Women's Health Initiative Randomized Controlled Dietary Modification Trial finds that postmenopausal women with established coronary heart disease were at increased risk of an adverse outcome if they consumed a low-fat 'heart-healthy' diet

The Women's Health Initiative Randomized Controlled Dietary Modification Trial (WHIRCDMT) was designed to test whether the US Department of Agriculture's 1977 Dietary Guidelines for Americans protects against coronary heart disease (CHD) and other chronic diseases. The only significant finding in the original 2006 WHIRCDMT publication was that postmenopausal women with CHD randomised to a low-fat 'heart-healthy' diet in 1993 were at 26% greater risk of developing additional CHD events compared with women with CHD eating the control diet. A 2017 WHIRCDMT publication includes data for an additional 5 years of follow-up. It finds that CHD risk in this subgroup of postmenopausal women had increased further to 47%-61%. The authors present three post-hoc rationalisations to explain why this finding is 'inadmissible': (1) only women in this subgroup were less likely to adhere to the prescribed dietary intervention; (2) their failure to follow the intervention diet increased their CHD risk; and (3) only these women were more likely to not have received cholesterol-lowering drugs. These rationalisations appear spurious. Rather these findings are better explained as a direct consequence of postmenopausal women with features of insulin resistance (IR) eating a low-fat high-carbohydrate diet for 13 years. All the worst clinical features of IR, including type 2 diabetes mellitus (T2DM) in some, can be 'reversed' by the prescription of a high-fat low-carbohydrate diet. The Women's Health Study has recently reported that T2DM (10.71-fold increased risk) and other markers of IR including metabolic syndrome (6.09-fold increased risk) were the most powerful predictors of future CHD development in women; blood low-density lipoprotein-cholesterol concentration was a poor predictor (1.38-fold increased risk). These studies challenge the prescription of the low-fat high-carbohydrate heart-healthy diet, at least in postmenopausal women with IR, especially T2DM. According to the medical principle of 'first do no harm', this practice is now shown to be not evidence-based, making it scientifically unjustifiable, perhaps unethical.

Insulin resistance genetic risk score and burden of coronary artery disease in patients referred for coronary angiography

AIMS

Insulin resistance associates with development of metabolic syndrome and risk of cardiovascular disease. The link between insulin resistance and cardiovascular disease is complex and multifactorial. Confirming the genetic link between insulin resistance, type 2 diabetes, and coronary artery disease, as well as the extent of coronary artery disease, is important and may provide better risk stratification for patients at risk. We investigated whether a genetic risk score of 53 single nucleotide polymorphisms known to be associated with insulin resistance phenotypes was associated with diabetes and burden of coronary artery disease.

METHODS AND RESULTS

We genotyped patients with a coronary angiography performed in the capital region of Denmark from 2010-2014 and constructed a genetic risk score of the 53 single nucleotide polymorphisms. Logistic regression using quartiles of the genetic risk score was performed to determine associations with diabetes and coronary artery disease. Associations with the extent of coronary artery disease, defined as one-, two- or three-vessel coronary artery disease, was determined by multinomial logistic regression. We identified 4,963 patients, of which 17% had diabetes and 55% had significant coronary artery disease. Of the latter, 27%, 14% and 14% had one, two or three-vessel coronary artery disease, respectively. No significant increased risk of diabetes was identified comparing the highest genetic risk score quartile with the lowest. An increased risk of coronary artery disease was found for patients with the highest genetic risk score quartile in both unadjusted and adjusted analyses, OR 1.21 (95% CI: 1.03, 1.42, p = 0.02) and 1.25 (95% CI 1.06, 1.48, p<0.01), respectively. In the adjusted multinomial logistic regression, patients in the highest genetic risk score quartile were more likely to develop three-vessel coronary artery disease compared with patients in the lowest genetic risk score quartile, OR 1.41 (95% CI: 1.10, 1.82, p<0.01).

CONCLUSIONS

Among patients referred for coronary angiography, only a strong genetic predisposition to insulin resistance was associated with risk of coronary artery disease and with a greater disease burden.

Hepatic Energy Metabolism Underlying Differential Lipidomic Responses to High-Carbohydrate and High-Fat Diets in Male Wistar Rats

BACKGROUND

Low-carbohydrate diets are suggested to exert metabolic benefits by reducing circulating triacylglycerol (TG) concentrations, possibly by enhancing mitochondrial activity.

OBJECTIVE

We aimed to elucidate mechanisms by which dietary carbohydrate and fat differentially affect hepatic and circulating TG, and how these mechanisms relate to fatty acid composition.

METHODS

Six-week-old, ∼300 g male Wistar rats were fed a high-carbohydrate, low-fat [HC; 61.3% of energy (E%) carbohydrate] or a low-carbohydrate, high-fat (HF; 63.5 E% fat) diet for 4 wk. Parameters of lipid metabolism and mitochondrial function were measured in plasma and liver, with fatty acid composition (GC), high-energy phosphates (HPLC), carnitine metabolites (HPLC-MS/MS), and hepatic gene expression (qPCR) as main outcomes.

RESULTS

In HC-fed rats, plasma TG was double and hepatic TG 27% of that in HF-fed rats. The proportion of oleic acid (18:1n-9) was 60% higher after HF vs. HC feeding while the proportion of palmitoleic acid (16:1n-7) and vaccenic acid (18:1n-7), and estimated activities of stearoyl-CoA desaturase, SCD-16 (16:1n-7/16:0), and de novo lipogenesis (16:0/18:2n-6) were 1.5-7.5-fold in HC vs. HF-fed rats. Accordingly, hepatic expression of fatty acid synthase (Fasn) and acetyl-CoA carboxylase (Acaca/Acc) was strongly upregulated after HC feeding, accompanied with 8-fold higher FAS activity and doubled ACC activity. There were no differences in expression of liver-specific biomarkers of mitochondrial biogenesis and activity (Cytc, Tfam, Cpt1, Cpt2, Ucp2, Hmgcs2); concentrations of ATP, AMP, and energy charge; plasma carnitine/acylcarnitine metabolites; or peroxisomal fatty acid oxidation.

CONCLUSIONS

In male Wistar rats, dietary carbohydrate was converted into specific fatty acids via hepatic lipogenesis, contributing to higher plasma TG and total fatty acids compared with high-fat feeding. In contrast, the high-fat, low-carbohydrate feeding increased hepatic fatty acid content, without affecting hepatic mitochondrial fatty acid oxidation.

Therapeutic potential of targeting oxidative stress in diabetic cardiomyopathy

Even in the absence of coronary artery disease and hypertension, diabetes mellitus (DM) may increase the risk for heart failure development. This risk evolves from functional and structural alterations induced by diabetes in the heart, a cardiac entity termed diabetic cardiomyopathy (DbCM). Oxidative stress, defined as the imbalance of reactive oxygen species (ROS) has been increasingly proposed to contribute to the development of DbCM. There are several sources of ROS production including the mitochondria, NAD(P)H oxidase, xanthine oxidase, and uncoupled nitric oxide synthase. Overproduction of ROS in DbCM is thought to be counterbalanced by elevated antioxidant defense enzymes such as catalase and superoxide dismutase. Excess ROS in the cardiomyocyte results in further ROS production, mitochondrial DNA damage, lipid peroxidation, post-translational modifications of proteins and ultimately cell death and cardiac dysfunction. Furthermore, ROS modulates transcription factors responsible for expression of antioxidant enzymes. Lastly, evidence exists that several pharmacological agents may convey cardiovascular benefit by antioxidant mechanisms. As such, increasing our understanding of the pathways that lead to increased ROS production and impaired antioxidant defense may enable the development of therapeutic strategies against the progression of DbCM. Herein, we review the current knowledge about causes and consequences of ROS in DbCM, as well as the therapeutic potential and strategies of targeting oxidative stress in the diabetic heart.

A novel numerical model of combination levels of C-peptide and insulin in coronary artery disease risk prediction

OBJECTIVE

Insulin resistance is a major risk factor for coronary artery disease (CAD). The C-peptide-to-insulin ratio (C/I) is associated with hepatic insulin clearance and insulin resistance. The current study was designed to establish a novel C/I index (CPIRI) model and provide early risk assessment of CAD.

METHODS

A total of 865 adults diagnosed with new-onset diabetes mellitus (DM) within one year and 54 healthy controls (HC) were recruited to develop a CPIRI model. The CPIRI model was established with fasting C/I as the independent variable and homeostasis model assessment of insulin resistance (HOMA-IR) as the dependent variable. Associations between the CPIRI model and the severity of CAD events were also assessed in 45 hyperglycemic patients with CAD documented via coronary arteriography (CAG) and whom underwent stress echocardiography (SE) and exercise electrocardiography test (EET).

RESULTS

Fasting C-peptide/insulin and HOMA-IR were hyperbolically correlated in DM patients and HC, and log(C/I) and log(HOMA-IR) were linearly and negatively correlated. The respective correlational coefficients were -0.83 (p < 0.001) and -0.76 (p < 0.001). The equations CPIRI(DM) = 670/(C/I)2.24 + 0.25 and CPIRI(HC) = 670/(C/I)2.24 - 1 (F = 1904.39, p < 0.001) were obtained. Patients with insulin resistance exhibited severe coronary artery impairment and myocardial ischemia. In CAD patients there was no significant correlation between insulin resistance and the number of vessels involved.

CONCLUSIONS

CPIRI can be used to effectively evaluate insulin resistance, and the combination of CPIRI and non-invasive cardiovascular examination is of great clinical value in the assessment of CAD.

Synthesis, biological evaluation, and molecular docking study of some new rohitukine analogs as protein tyrosine phosphatase 1B inhibitors

Rohitukine (RH) was extracted from the stem bark of Dysoxylum binectariferum Hook. It was derivatized to different arylsulphanmides by treating with the corresponding aryl sulphonyl chlorides. These derivatives were tested in-vitro on protein tyrosine phosphatase 1B (PTP1B) inhibition. Among these the active compounds K2, K3, K5, and K8 significantly inhibited the PTP1B by 51.3%, 65.6%, 71.9%, and 55.9% respectively at 10 µg/ml, the results were also supported by in-silico docking experiments. The most potent compound K5 was analyzed for antidiabetic and antidyslipidemic activity in vivo. It showed a marked reduction in blood glucose level (random and fasting) and serum insulin level in db/db mice. It improved glucose intolerance as ascertained by the oral glucose tolerance test (OGTT). These NCEs (New Chemical Entities) also lowered cholesterol and triglyceride profiles while improved high-density lipoprotein cholesterol in db/db mice. The K5 was further evaluated for antiadipogenic activity on MDI (Methylisobutylxanthine, dexamethasone, and insulin)-induced adipogenesis. where it significantly inhibited MDI-induced adipogenesis in 3 T3-L1 preadipocytes, at 10 µM and 20 µM concentration. These results were compared with the parent compound RH which inhibited 35% and 45% lipid accumulation while the RH analog K5 inhibited the lipid accumulation by 41% and 51% at 10 and 20 µM concentration, respectively. These results well corroborated with in-silico studies.

Predictive effect of triglyceride‑glucose index on clinical events in patients with type 2 diabetes mellitus and acute myocardial infarction: results from an observational cohort study in China

Background

Triglyceride glucose (TyG) index is considered a reliable alternative marker of insulin resistance and an independent predictor of cardiovascular (CV) outcomes. However, the prognostic value of TyG index in patients with type 2 diabetes mellitus (T₂DM) and acute myocardial infarction (AMI) remains unclear.

Methods

A total of 1932 consecutive patients with T₂DM and AMI were enrolled in this study. Patients were divided into tertiles according to their TyG index levels. The incidence of major adverse cardiac and cerebral events (MACCEs) was recorded. The TyG index was calculated as the ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2].

Results

Competing risk regression revealed that the TyG index was positively associated with CV death [2.71(1.92 to 3.83), p < 0.001], non-fatal MI [2.02(1.32 to 3.11), p = 0.001], cardiac rehospitalization [2.42(1.81 to 3.24), p < 0.001], revascularization [2.41(1.63 to 3.55), p < 0.001] and composite MACCEs [2.32(1.92 to 2.80), p < 0.001]. The area under ROC curve of the TyG index for predicting the occurrence of MACCEs was 0.604 [(0.578 to 0.630), p < 0.001], with the cut-off value of 9.30. The addition of TyG index to a baseline risk model had an incremental effect on the predictive value for MACCEs [net reclassification improvement (NRI): 0.190 (0.094 to 0.337); integrated discrimination improvement (IDI): 0.027 (0.013 to 0.041); C-index: 0.685 (0.663 to 0.707), all p < 0.001].

Conclusions

The TyG index was significantly associated with MACCEs, suggesting that the TyG index may be a valid marker for risk stratification and prognosis in patients with T₂DM and AMI.

Trial registration Retrospectively registered.

Metabolic and Energy Imbalance in Dysglycemia-Based Chronic Disease

Metabolic flexibility is the ability to efficiently adapt metabolism based on nutrient availability and requirement that is essential to maintain homeostasis in times of either caloric excess or restriction and during the energy-demanding state. This regulation is orchestrated in multiple organ systems by the alliance of numerous metabolic pathways under the master control of the insulin-glucagon-sympathetic neuro-endocrine axis. This, in turn, regulates key metabolic enzymes and transcription factors, many of which interact closely with and culminate in the mitochondrial energy generation machinery. Metabolic flexibility is compromised due to the continuous mismatch between availability and intake of calorie-dense foods and reduced metabolic demand due to sedentary lifestyle and age-related metabolic slowdown. The resultant nutrient overload leads to mitochondrial trafficking of substrates manifesting as mitochondrial dysfunction characterized by ineffective substrate switching and incomplete substrate utilization. At the systemic level, the manifestation of metabolic inflexibility comprises reduced skeletal muscle glucose disposal rate, impaired suppression of hepatic gluconeogenesis and adipose tissue lipolysis manifesting as insulin resistance. This is compounded by impaired β-cell function and progressively reduced β-cell mass. A consequence of insulin resistance is the upregulation of the mitogen-activated protein kinase pathway leading to a pro-hypertensive, atherogenic, and thrombogenic environment. This is further aggravated by oxidative stress, advanced glycation end products, and inflammation, which potentiates the risk of micro- and macro-vascular complications. This review aims to elucidate underlying mechanisms mediating the onset of metabolic inflexibility operating at the main target organs and to understand the progression of metabolic diseases. This could potentially translate into a pharmacological tool that can manage multiple interlinked conditions of dysglycemia, hypertension, and dyslipidemia by restoring metabolic flexibility. We discuss the breadth and depth of metabolic flexibility and its impact on health and disease.