Insulin resistance predicts mortality in nondiabetic individuals in the U.S

Association of Appendicular Skeletal Muscle Mass Index and Insulin Resistance With Mortality in Multi-Nationwide Cohorts

BACKGROUND

Although sarcopenia and insulin resistance are closely related, there is limited evidence regarding how they interact to influence mortality across different population groups. The purpose of this study was to examine the relationship between skeletal muscle mass and insulin resistance and its impact on mortality and cardiovascular disease risk using large-scale national data from Korea and the United States.

METHODS

We analysed data from the National Health and Nutrition Examination Survey (NHANES) 1999-2006 and 2011-2018 and the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011, with mortality follow-up through to 2019. Cox regression models were used to assess the effects of muscle mass (appendicular skeletal mass index, ASMI) and insulin resistance on all-cause and major adverse cardiovascular and cerebrovascular events (MACCE)-related mortality. Mediation analysis was performed to examine direct and indirect effects.

RESULTS

The study included 8036 participants from NHANES and 14 449 from KNHANES. The sarcopenia group demonstrated a lower homeostasis model assessment for insulin resistance and better metabolic indices than the normal group despite having a higher mortality rate. Insulin resistance positively correlated with muscle mass (r = 0.203, p < 0.001 in the NHANES; r = 0.143, p < 0.001 in the KNHANES), and both insulin resistance and sarcopenia were identified as independent risk factors for all-cause and MACCE-related mortality. When the participants were categorized into four groups based on the presence or absence of insulin resistance and sarcopenia, those with both conditions exhibited the highest risk of all-cause mortality (hazard ratio [HR]: 2.30, 95% confidence interval [CI]: 1.72-3.08 in the NHANES; HR: 2.60, 95% CI: 2.14-3.16 in the KNHANES) and MACCE-related mortality among the groups (HR: 3.18, 95% CI: 1.99-5.08 in the NHANES; HR: 2.47, 95% CI: 1.66-3.69 in the KNHANES). Mediation analysis revealed that low muscle mass was associated with decreased insulin resistance but directly increased both all-cause mortality and MACCE-related mortality (NHANES: total natural direct effects [TNDE], HR: 2.08, 95% CI: 1.57-2.76; KNHANES: TNDE, HR: 1.69, 95% CI: 1.28-2.23).

CONCLUSIONS

This study found that low ASMI was inversely associated with insulin resistance and positively associated with mortality risk in both cohorts. These findings, consistent across two large national studies, highlight the complex relationships between muscle mass, insulin sensitivity and mortality. Further studies are needed to assess the underlying mechanisms and clinical implications of these associations.

TRIAL REGISTRATION

Clinicaltrials.gov ID: NCT05616013.

Excessively Low Insulin Resistance May Increase the Risk of All-Cause Mortality Among Community-Dwelling Individuals Without Diabetes

Background Epidemiological evidence has indicated that insulin resistance (IR), as measured by a homeostatic model assessment for IR (HOMA-IR), is strongly correlated with body mass index (BMI). However, there is a paucity of studies assessing the complex interaction between BMI and HOMA-IR with respect to all-cause mortality, particularly among Asian individuals without diabetes. Materials and methods The research centered on individuals diagnosed without diabetes, comprising 881 men with a mean age of 62 years (± standard deviation (SD): 14) and 1,159 women with a mean age of 64 years (± 11). The participants were drawn from the Nomura cohort study, consisting of two cohorts: one initiated in 2002 and the other in 2014. To assess the risk of all-cause mortality up to the end of the follow-up period, we applied a Cox proportional hazards model, adjusting for a range of covariates to calculate the hazard ratios (HRs). Results Participants were followed for a median duration of 7,691 days (interquartile range: 4,235-7,761 days). Over the course of the follow-up period, a total of 672 deaths were documented, comprising 338 deaths among men and 334 among women. The interaction between BMI and HOMA-IR (HR: 1.05; 95% confidence interval (CI): 1.02-1.09) was significantly associated with all-cause mortality, along with gender, age, BMI, history of cardiovascular disease, hyperuricemia, and HOMA-IR. Moreover, the HRs for all-cause mortality were examined for each BMI group by dividing the HOMA-IR by one SD. In the BMI < 22.0 kg/m² group, using the third HOMA-IR as the reference, significant HR (J curve) increases were observed in the first, second, and fourth HOMA-IR. In the BMI ≥ 22.0 kg/m² group, using the first HOMA-IR as the reference, a significant increase in HR was observed only in the fourth HOMA-IR. An interaction between BMI and HOMA-IR was identified for all-cause mortality (p = 0.005). Conclusions BMI confounds the association between IR, as measured by HOMA-IR, and the risk of all-cause mortality among Japanese individuals.

Inflammation factors mediate the association between heavy metal and Homa-IR index: An integrated approach from the NHANES (2011∼2016)

INTRODUCTION

The interplay between heavy metals exposure and insulin resistance (IR), specifically through the mediation of inflammation factors, is crucial for understanding metabolic disturbances. This study utilizes data from the NHANES (2011∼2016) to investigate these relationships in a large, diverse U.S.

POPULATION

METHODS

The study analyzed the associations between heavy metals (cadmium (Cd), lead (Pb), mercury (Hg), manganese (Mn)) and the Homeostatic Model Assessment for Insulin Resistance (Homa-IR) index. The analyses included descriptive statistics, Pearson's correlations, linear and non-linear regression models, and advanced statistical models such as Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR). Inflammation factors were assessed for their mediating role in these associations.

RESULTS

The findings highlighted significant positive correlations between specific heavy metals and the Homa-IR index. Both linear and non-linear associations were evident, with certain metals showing a more pronounced impact in the presence of high inflammation markers. It was found that the Homa-IR index was negatively associated with Pb (β (95 %CI) = -0.0126 (-0.0238 ∼ -0.0015), P = 0.0268) and Hg (β (95 %CI) = -0.0090 (-0.0180 ∼ -0.0001), P = 0.0487). The WQS regression indicated an overall positive relationship between heavy metal mixtures (Estimate: 0.0050, P < 0.05) and the Homa-IR index where Cu had the highest weights (0.7741), while BKMR analyses detailed the varying effects of individual metals at different exposure levels. In the mediation analysis, it can be found that monocyte (Mono) mediated the association between Pb and Homa-IR index (direct effect:0.0546, indirect effect:0.0082) and neutrophil (Neu) (direct effect:0.0521, indirect effect:0.0047) can mediate the association between Hg and Homa-IR index.

CONCLUSIONS

This study confirms that exposure to heavy metals is associated with increased insulin resistance and that inflammation significantly mediates this relationship. Understanding these pathways is essential for developing targeted interventions to mitigate the metabolic consequences of environmental exposures.

Effect of a Supervised Aerobic Exercise Training Program and Ginkgo Biloba Extract on Metabolic Parameters and Functional Capacity in HIV-Infected Subjects

Background: A remarkable increase in metabolic comorbidities occur in people living with HIV infection (PLWH). Supervised physical activity provides significant health benefits. Ginkgo biloba (GKB) extract has been reported to have a wide range of metabolic advantages. This study aimed to examine the effects of an exercise training (ET) program and a GKB extract on PLWH. Methods: This was a randomized placebo-controlled double-blind study. Twenty-eight PLWH were assigned to receive a placebo (n = 10), GKB extract (n = 10), or statins (n = 8). All patients underwent a supervised ET program 3-5 times per week. Anthropometric measurements, functional capacities, and metabolic parameters were assessed in all participants at baseline and after 12 weeks of follow-up. Results: After the 12-week intervention, body fat decreased significantly by 2-3% in all groups relative to their baseline values (p < 0.05). Total cholesterol and LDL-c were significantly decreased in the ET + statin group (p = 0.04, and p = 0.007, respectively) compared to baseline values, while HbA1c and the HOMA-IR index were significantly decreased in the ET + GKB group (p = 0.03 and p = 0.02, respectively) compared to baseline values, and a significant increase in CD4+ T cell mean was observed in the ET + placebo group (p = 0.005) compared to baseline values. A significant increase in cardiorespiratory capacity (VO2max) from their baseline values was observed in all groups (p < 0.001) after 12 weeks of intervention from their baseline values. Conclusions: Body fat and cardiorespiratory fitness significantly improved after a 12-week supervised ET program. GKB extract significantly decreased insulin resistance.

Course and trajectories of insulin resistance, incident heart failure and all-cause mortality in nondiabetic people

BACKGROUND

In nondiabetic people, the long-term effects of insulin resistance (IR) on heart failure (HF) and all-cause mortality have not been studied.

OBJECTIVES

To examine the association between IR trajectories and incident HF and all-cause mortality in a nondiabetic population.

METHODS

We studied 7835 nondiabetic participants from the Atherosclerosis Risk in Communities (ARIC) Study. We estimated IR with several methods: Homeostatic Model Assessment-Insulin Resistance (HOMA-IR), triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), triglyceride glucose Index (TyG Index), and metabolic score for insulin resistance (METS-IR). The latent class analysis identified two trajectories for HOMA-IR ('low level' and 'high level'), and three trajectories for TG/HDL-C, TyG index, and METS-IR ('low level', 'moderate level', and 'high level'). Cox proportional hazard models were employed to examine the association.

RESULTS

Participants in the 'high level' group of HOMA-IR trajectory patterns were more likely to have incident HF and all-cause mortality with HRs (95% CIs) of 1.29 (1.11-1.50) and 1.31(1.19-1.44), respectively, compared to the 'low level' group. Similarly, participants in the 'moderate level' and 'high level' groups of TG/HDL-C, TyG index, and METS-IR trajectories had elevated risks of incident HF and all-cause mortality. However, no increased risk was found for all-cause mortality for men in the 'moderate level' and 'high level' group of TG/HDL-C, TyG index, and METS-IR relative to the 'low level' group.

CONCLUSIONS

Long-term moderate and high IR levels were positively associated with increased risks of incident HF for both males and females. For all-cause mortality, however, consistent associations were found only in women.

Predictive value of TG/HDL-C and GFR-adjusted uric acid levels on cardiovascular mortality: the URRAH study

BACKGROUND

Insulin resistance (IR) and serum uric acid (SUA) are closely interconnected: SUA contributes to adversely affects the insulin signaling pathway and contributes to IR, while IR is a known predictor for the development of hyperuricemia. The triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio has been proposed as an easily obtainable marker for IR. This research aimed to investigate the interaction between IR and glomerular filtration rate (GFR)-adjusted uricemia (SUA/GFR ratio) in determining CV risk in a large population cohort study.

METHODS

Data from 18,694 subjects were analyzed from Uric acid Right foR heArt Healt (URRAH) database. The study evaluated the association between TG/HDL-C ratio and SUA/GFR ratio, as well as their impact on the development of outcomes during the follow-up study period. The primary endpoint was CV mortality.

RESULTS

After a mean follow-up of 124 ± 64 months, 2,665 (14.2%) CV deaths occurred. The incidence of fatal and non-fatal CV events increased in parallel with the increase of TG/HDL-C quintiles. TG/HDL-C ratio showed a positive association with increasing of SUA/GFR ratio, even in non-diabetic patients. Multivariate analysis showed that the TG/HDL-C ratio increases the mortality risk even after adjustment for potential confounding factors. Finally, IR and GFR-adjusted hyperuricemia showed an additive effect on CV mortality.

CONCLUSIONS

Both IR and SUA/GFR ratio independently predict CV mortality, regardless of age, gender, BMI, diabetes, hypertension and statin use. The joint effect of the TG/HDL-C ratio and the elevated SUA/GFR ratio was greater than the presence of each single risk factor on CV mortality. This highlights the importance of monitoring these markers to better assess cardiovascular risk.

Analyzing the impact of glycemic metabolic status on cardiovascular mortality and all-cause mortality related to the estimated glucose disposal rate: a nationwide cohort study

Objective

The Estimated Glucose Disposal Rate (eGDR) serves as a surrogate marker for insulin resistance, with numerous studies highlighting its significant prognostic value. This paper aims to analyze the impact of eGDR on cardiovascular and all-cause mortality across different glycemic metabolic statuses, including normal fasting glucose (NFG), prediabetes, and diabetes.

Methods

This study included 46,016 American adults who underwent health examinations as part of the National Health and Nutrition Examination Survey from 1999 to 2018. Multivariable Cox regression was employed to explore the relationships between eGDR and mortality rates under varying glycemic states. Additionally, Kaplan-Meier curves were used to compare the cumulative incidence of cardiovascular and all-cause mortality across different metabolic statuses. Finally, the predictive value of eGDR for mortality was assessed using receiver operating characteristic curves.

Results

During an average follow-up of 115 months, a total of 6,906 (15.01%) participants experienced all-cause mortality, with 1,798 (3.91%) deaths attributed to cardiovascular causes. Kaplan-Meier analysis revealed that higher eGDR levels were associated with gradually reduced mortality rates. After adjusting for confounders, elevated eGDR levels were protective against both cardiovascular and all-cause mortality; the protective effect was notably stronger for cardiovascular mortality [Cardiovascular mortality hazard ratio: 0.92; All-cause mortality hazard ratio: 0.94]. Further interaction tests indicated that glycemic status significantly modified the protective effect of eGDR (P-interaction<0.0001); specifically, high eGDR conferred stronger protection against cardiovascular and all-cause mortality in individuals with NFG and prediabetes compared to those with diabetes. Receiver operating characteristic analysis suggested that eGDR had superior predictive value for mortality in the NFG and prediabetic populations compared to the diabetic group.

Conclusion

eGDR is a straightforward surrogate for insulin resistance, acting as a protective factor against cardiovascular and all-cause mortality in American adults, with glycemic status modifying this protective effect. Specifically, high eGDR levels offer stronger protection in individuals with NFG and prediabetes compared to those with diabetes; moreover, eGDR appears to be more suitable for predicting mortality events in the NFG and prediabetic populations.

Elevated Fasting C-Peptide Levels Correlate with Increased 10-Year Risk of Atherosclerotic Cardiovascular Disease in Newly Diagnosed Type 2 Diabetes Patients

Purpose

This study aims to analyze the impact of serum C-peptide levels in patients with newly diagnosed type 2 diabetes (T2DM) on the 10-year risk of atherosclerotic cardiovascular disease (ASCVD).

Patients and Methods

A total of 1923 patients with newly diagnosed T2DM were selected and categorized into four groups based on the interquartile range of fasting C-peptide (FCP) levels: Q1 group (FCP≤0.568 ng/mL), Q2 group (0.568 < FCP≤0.751 ng/mL), Q3 group (0.751 < FCP≤0.980 ng/mL), and Q4 group (FCP > 0.980 ng/mL). Clinical data were collected, and the China-PAR model was employed to evaluate the risk score of ASCVD within 10 years. Additionally, the correlation between FCP levels and the risk of ASCVD was analyzed.

Results

As the quartiles of FCP increased, the 10-year ASCVD risk exhibited a gradual increase. The risk score in the FCP > 0.980 ng/mL group was significantly higher than that in the other groups, with noted differences related to gender and weight. Multiple linear regression analysis indicated that, even after adjusting for confounding factors such as gender, age, body mass index (BMI), and glycosylated hemoglobin, FCP levels remained a positive predictor of the 10-year ASCVD risk.

Conclusion

High FCP levels are identified as a risk factor for ASCVD within 10 years in patients with newly diagnosed T2DM.

Effects of Various Heavy Metal Exposures on Insulin Resistance in Non-diabetic Populations: Interpretability Analysis from Machine Learning Modeling Perspective

Increasing and compelling evidence has been proved that heavy metal exposure is involved in the development of insulin resistance (IR). We trained an interpretable predictive machine learning (ML) model for IR in the non-diabetic populations based on levels of heavy metal exposure. A total of 4354 participants from the NHANES (2003-2020) with complete information were randomly divided into a training set and a test set. Twelve ML algorithms, including random forest (RF), XGBoost (XGB), logistic regression (LR), GaussianNB (GNB), ridge regression (RR), support vector machine (SVM), multilayer perceptron (MLP), decision tree (DT), AdaBoost (AB), Gradient Boosting Decision Tree (GBDT), Voting Classifier (VC), and K-Nearest Neighbour (KNN), were constructed for IR prediction using the training set. Among these models, the RF algorithm had the best predictive performance, showing an accuracy of 80.14%, an AUC of 0.856, and an F1 score of 0.74 in the test set. We embedded three interpretable methods, the permutation feature importance analysis, partial dependence plot (PDP), and Shapley additive explanations (SHAP) in RF model for model interpretation. Urinary Ba, urinary Mo, blood Pb, and blood Cd levels were identified as the main influencers of IR. Within a specific range, urinary Ba (0.56-3.56 µg/L) and urinary Mo (1.06-20.25 µg/L) levels exhibited the most pronounced upwards trend with the risk of IR, while blood Pb (0.05-2.81 µg/dL) and blood Cd (0.24-0.65 µg/L) levels showed a declining trend with IR. The findings on the synergistic effects demonstrated that controlling urinary Ba levels might be more crucial for the management of IR. The SHAP decision plot offered personalized care for IR based on heavy metal control. In conclusion, by utilizing interpretable ML approaches, we emphasize the predictive value of heavy metals for IR, especially Ba, Mo, Pb, and Cd.

Association between stress hyperglycemia ratio and postoperative major adverse cardiovascular and cerebrovascular events in noncardiac surgeries: a large perioperative cohort study

BACKGROUND

There has been a concerning rise in the incidence of major adverse cardiovascular and cerebrovascular events (MACCE) following noncardiac surgeries (NCS), significantly impacting surgical outcomes and patient prognosis. Glucose metabolism abnormalities induced by stress response under acute medical conditions may be a risk factor for postoperative MACCE. This study aims to explore the association between stress hyperglycemia ratio (SHR) and postoperative MACCE in patients undergoing general anesthesia for NCS.

METHODS

There were 12,899 patients in this perioperative cohort study. The primary outcome was MACCE within 30 days postoperatively, defined as angina, acute myocardial infarction, cardiac arrest, arrhythmia, heart failure, stroke, or in-hospital all-cause mortality. Kaplan-Meier curves visualized the cumulative incidence of MACCE. Cox proportional hazard models were utilized to assess the association between the risk of MACCE and different SHR groups. Restricted cubic spline analyses were conducted to explore potential nonlinear relationships. Additionally, exploratory subgroup analyses and sensitivity analyses were performed.

RESULTS

A total of 592 (4.59%) participants experienced MACCE within 30 days after surgery, and 1,045 (8.10%) within 90 days. After adjusting for confounding factors, compared to the SHR T2 group, the risk of MACCE within 30 days after surgery increased by 1.34 times (95% CI 1.08-1.66) in the T3 group and by 1.35 times (95% CI 1.08-1.68) in the T1 group respectively. In the non-diabetes group, the risk of MACCE within 30 days after surgery increased by 1.60 times (95% CI 1.21-2.12) in the T3 group and by 1.61 times (95% CI 1.21-2.14) in the T1 group respectively, while no statistically significant increase in risk was observed in the diabetes group. Similar results were observed within 90 days after surgery in the non-diabetes group. Additionally, a statistically significant U-shaped nonlinear relationship was observed in the non-diabetes group (30 days: P for nonlinear = 0.010; 90 days: P for nonlinear = 0.008).

CONCLUSION

In this large perioperative cohort study, we observed that both higher and lower SHR were associated with an increased risk of MACCE within 30 and 90 days after NCS, especially in patients without diabetes. These findings suggest that SHR potentially plays a key role in stratifying cardiovascular and cerebrovascular risk after NCS.

Lower Insulin Sensitivity Through 36 Months of Life With in Utero HIV and Antiretroviral Exposure in Botswana: Results From the Tshilo Dikotla Study

BACKGROUND

There are little data on changes in insulin sensitivity during the first few years of life following in utero human immunodeficiency virus (HIV) and antiretroviral (ARV) exposure.

METHODS

The Tshilo Dikotla study enrolled pregnant persons with HIV (PWH) (receiving tenofovir/emtricitabine or lamivudine plus dolutegravir or efavirenz) and pregnant individuals without HIV, as well as their liveborn children. Newborns were randomized to receive either zidovudine (AZT) or nevirapine (NVP) postnatal prophylaxis. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was assessed at birth and 1, 18, 24, and 36 months of life. We fit linear mixed-effects models to evaluate the association between in utero HIV/ARV exposure and average HOMA-IR from birth through 36 months of life, adjusting for confounders.

RESULTS

A total of 419 children were included (287 with in utero HIV/ARV exposure and uninfected [CHEU] and 132 without in utero HIV/ARV exposure [CHUU]). CHEU were born to older women (29.6 vs 25.3 years of age) with higher gravidity (3 vs 1). HOMA-IR was persistently higher in CHEU versus CHUU in adjusted analyses (mean difference of 0.07 in log10 HOMA-IR, P = .02) from birth through 36 months of life. Among CHEU, no differences in HOMA-IR were observed from birth through 36 months by in utero ARV exposure status or between AZT and NVP infant prophylaxis arms.

CONCLUSIONS

In utero HIV/ARV exposure was associated with lower insulin sensitivity throughout the first 36 months of life, indicating persistent early life metabolic disturbances which may raise concern for poorer metabolic health later in life.

Insulin-based or non-insulin-based insulin resistance indicators and risk of long-term cardiovascular and all-cause mortality in the general population: A 25-year cohort study

OBJECTIVE

Although insulin resistance (IR) has been recognized to be a causal component in various diseases, current information on the relationship between IR and long-term mortality in the general population is limited and conclusions varied among different IR indicators and different populations. We aimed to assess associations between different measurements of IR with long-term all-cause mortality and cardiovascular mortality risk for the general population.

RESEARCH DESIGN AND METHODS

We included 13,909 individuals from the Third National Health and Nutrition Examination Survey. Mortality was identified via National Death Index information until December 31, 2019. IR was measured using fasting insulin, homeostasis model assessment of IR (HOMA-IR), homeostasis model assessment of β-cell function, quantitative insulin sensitivity check index (QUICKI), insulin-to-glucose ratio (IGR), triglyceride glucose (TyG) index, TyG-body mass index (TyG-BMI), and hypertriglyceridemic-waist phenotype.

RESULTS

During median 25-year follow-up, 5,306 all-cause mortality events occurred. After multivariate adjustment, variables significantly associated with elevated all-cause mortality risk were (hazard ratio [95 % confidence interval]): higher insulin (1.07 [1.02;1.13]); HOMA-IR (1.08 [1.03;1.13]); IGR (1.05 [1.00;1.11]); TyG (1.07 [1.00;1.14]); TyG-BMI (1.24 [1.02;1.51]); lower QUICKI (0.91 [0.86-0.96]). After stratification by diabetes status, higher insulin, HOMA-IR, TyG-BMI and lower QUICKI were significantly associated with increased risk of all-cause mortality in both diabetes and non-diabetes populations (all P for interaction > 0.05). Higher TyG (adjusted HR 1.17 [1.09;1.26], P for interaction = 0.018) and hypertriglyceridemic-waist phenotype (adjusted HR 1.26 [1.08;1.46], P for interaction = 0.047) were significantly associated with increased risk of all-cause mortality in patients with diabetes, however, these associations could not be seen in people without diabetes. Similar results were observed between the above-mentioned IR indicators and cardiovascular death.

CONCLUSIONS

Fasting insulin, HOMA-IR, TyG-BMI, and QUICKI may indicate mortality risk in diabetes and non-diabetes populations, with TyG and the hypertriglyceridemic-waist phenotype showing particular relevance for individuals with diabetes. Further studies are needed to validate these findings and determine their broader applicability.

Insulin Resistance-Related Cardiometabolic Risk Among Nondiabetic Childbearing Age Females

Background: This study evaluates insulin resistance prevalence in young females without diabetes, assessing risk factors and adiposity indices for early detection of cardiometabolic disorders. Methods: A cross-sectional study was conducted, involving 282 females aged 18-35 years from suburban and rural areas of Sri Lanka. Anthropometric measurements [height, weight, waist circumference (WC)] were obtained and biochemical parameters [fasting glucose, insulin, insulin resistance (IR), total cholesterol, high-density lipoproteins, (HDL), low-density lipoproteins, triglycerides] were measured. The anthropometric and biochemical data were compared between the groups of normal weight controls and overweight/obese cases, as well as between females with or without IR. Results: The prevalence of IR in controls and cases were 48.6% and 57.1%, respectively. Both groups had mean Homeostasis Model Assessment-IR values greater than the normal cutoff value of 2.5. Females with IR showed higher prevalence of dyslipidemia than those without IR. Compared to the controls (2.81%), the prevalence of metabolic syndrome (MetS) was substantially greater among cases (46.42%). Both groups showed a statistically significant association between IR and MetS, but the association was considerably stronger in cases [r = 0.616, odds ratio (OR) >8] than in controls (r = 0.175, OR >1). Controls exhibited lower HDL levels, hypertriglyceridemia, and elevated IR levels (P < 0.05), and their ORs for acquiring MetS were >2, <1, and >3, respectively. Importantly, overweight/obese cases exhibited a significant association (P < 0.05) with all the MetS risk variables. Visceral adiposity index (VAI) proves to be a precise measurement for identifying IR and cardiovascular disease (CVD) among young females (Z = -3.651), surpassing the accuracy of other indices. Body mass index, body round index, a body shape index, and WC were also reliable measurements to assess IR and the risk of CVD (P < 0.05). Conclusion: The study underscores the importance of assessing IR in nondiabetic young females to identify early cardiometabolic risks. VAI emerges as a precise measurement for identifying IR and CVD risk, surpassing the accuracy of other indices.

Effect of combination pioglitazone with sodium-glucose cotransporter-2 inhibitors or glucagon-like peptide-1 receptor agonists on outcomes in type 2 diabetes: A systematic review, meta-analysis, and real-world study from an international federated database

AIMS

To evaluate the efficacy and cardiovascular outcomes of combination pioglitazone with either a glucagon-like peptide-1 receptor agonist (GLP-1RA) or a sodium-glucose cotransporter-2 (SGLT2) inhibitor in individuals with type 2 diabetes (T2D) by conducting a systematic review, meta-analysis, and analysis of a large international real-world database.

METHODS

We searched MEDLINE, SCOPUS and Web of Science to identify relevant articles for inclusion (PROSPERO [CRD: 42023483126]). Nineteen studies assessing pioglitazone + SGLT2 inhibitors or GLP-1RAs versus controls were identified, 16 of which were randomized controlled trials. Risk of bias was assessed using Cochrane-endorsed tools and quality of evidence was assessed using GRADE. We additionally performed a retrospective cohort study of all individuals aged 18 years or over with T2D, using the TriNetX platform. We included propensity-score-matched individuals who were treated for at least 1 year with pioglitazone and a GLP-1RA or pioglitazone and an SGLT2 inhibitor, compared against GLP-1RA and SGLT2 inhibitor monotherapy. Outcomes were all-cause mortality, heart failure, chronic kidney disease and composite stroke and transient ischaemic attack.

RESULTS

The average follow-up in the included studies ranged from 24 to 52 weeks. Combination of pioglitazone with a GLP-1RA reduced glycated haemoglobin (HbA1c) and weight greater than in controls: mean differences -1% (95% confidence interval [CI] -1.27, -0.74) and -1.19 kg (95% CI -1.80, -0.58), respectively. There was no statistically significant difference in systolic blood pressure (SBP) or mortality between groups: mean difference - 1.56 mmHg (95% CI -4.48, 1.35; p = 0.30) and relative risk (RR) 0.29 (95% CI 0.07-1.15; p = 0.08), respectively. Combination of pioglitazone with SGLT2 inhibitors reduced HbA1c, weight and SBP to a greater extent than control treatment: mean differences -0.48% (95% CI -0.67, -0.28), -2.3 kg (95% CI -2.72, -1.88) and -2.4 mmHg (95% CI -4.1, -0.7; p = 0.01), respectively. There was no statistically significant difference in mortality between groups (RR 1.81, 95% CI 0.30-10.97; p = 0.52). The included trials demonstrated a reduction in risk of heart failure with combination treatment. Similarly, from the real-world database (n = 25 230 identified), pioglitazone and SGLT2 inhibitor combination therapy was associated with reduced risk of heart failure compared to monotherapy alone (hazard ratio 0.50, 95% CI 0.38-0.65; p < 0.001).

CONCLUSION

Both our systematic review/meta-analysis and the real-world dataset show that combination of pioglitazone with either GLP-1RAs or SGLT2 inhibitors is associated with increased weight loss and reduced risk of heart failure compared with monotherapy.

Gut permeability is associated with lower insulin sensitivity in youth with perinatally acquired HIV

The relationships between alterations in the intestinal barrier, and bacterial translocation with the development of metabolic complications in youth with perinatally acquired HIV (YPHIV) have not been investigated. The PHACS Adolescent Master Protocol enrolled YPHIV across 15 U.S. sites, including Puerto Rico, from 2007 to 2009. For this analysis, we included YPHIV with HIV viral load 1000 c/ml or less, with at least one measurement of homeostatic assessment of insulin resistance (HOMA-IR) or nonhigh density lipoprotein (non-HDLc) between baseline and year 3 and plasma levels of intestinal fatty-acid binding protein (I-FABP), lipopolysaccharide-binding protein (LBP), and zonulin levels at baseline. We fit linear regression models using generalized estimating equations to assess the association of baseline log 10 gut markers with log 10 HOMA-IR and non-HDLc at all timepoints. HOMA-IR or non-HDLc was measured in 237, 189, and 170 PHIV at baseline, Yr2, and Yr3, respectively. At baseline, median age (Q1, Q3) was 12 years (10, 14), CD4 + cell count was 762 cells/μl (574, 984); 90% had HIV RNA less than 400 c/ml. For every 10-fold higher baseline I-FABP, HOMA-IR dropped 0.85-fold at baseline and Yr2. For a 10-fold higher baseline zonulin, there was a 1.35-fold increase in HOMA-IR at baseline, 1.23-fold increase in HOMA-IR at Yr2, and 1.20-fold increase in HOMA-IR at Yr3 in adjusted models. For a 10-fold higher baseline LBP, there was a 1.23-fold increase in HOMA-IR at baseline in the unadjusted model, but this was slightly attenuated in the adjusted model. Zonulin was associated with non-HDLc at baseline, but not for the other time points. Despite viral suppression, intestinal damage may influence downstream insulin sensitivity in YPHIV.

Prognostic Implications of Insulin Resistance in Heart Failure in Japan

Diabetes mellitus (DM) is a major risk and prognostic factor for heart failure (HF). Insulin resistance (IR) is an important component of DM, but the relationship between IR and HF prognosis has not yet been established across a wide variety of HF populations. We retrospectively evaluated the relationship between IR and clinical outcomes of HF patients at our hospital between 2017 and 2021. IR was defined as a homeostatic model assessment of IR (HOMA-IR) index ≥ 2.5, calculated from fasting blood glucose and insulin concentrations. The primary outcome was a composite of all-cause death and hospitalisation for HF (HHF). Among 682 patients included in the analyses, 337 (49.4%) had IR. The median age was 70 [interquartile range (IQR): 59-77] years old, and 66% of the patients were men. Among the patients, 41% had a left ventricular ejection fraction below 40%, and 32% had DM. The median follow-up period was 16.5 [IQR: 4.4-37.3] months. IR was independently associated with the primary outcome (HR: 1.91, 95% CI: 1.39-2.62, p < 0.0001), death (hazard ratio [HR]: 1.86, 95% confidence interval [CI]: 1.28-2.83, p < 0.01), and HHF (HR: 1.91, 95% CI: 1.28-2.83, p < 0.01). HOMA-IR is an independent prognostic factor of HF in a wide variety of HF populations.

Association between metabolic score for insulin resistance and clinical outcomes: insights from the Tehran lipid and glucose study

BACKGROUND

We aimed to assess the relationship between Metabolic Score for Insulin Resistance (METS-IR) and the incidence of coronary heart disease (CHD), stroke, mortality, diabetes, hypertension, and chronic kidney disease (CKD) in a population from the Middle East and North Africa (MENA) region.

METHOD

Individuals aged ≥ 20 years were enrolled. Cox proportional hazards regression models were applied to assess the association between METS-IR and incident CHD, stroke, all-cause mortality, diabetes, hypertension, and CKD.

RESULTS

Over a median follow-up period of 9-18 years, 1080 (10.6%), 267 (2.6%), 1022 (9.6%), 1382 (16.4%), 2994 (58.5%), and 2002 (23.0%) CHD, stroke, all-cause mortality, diabetes, hypertension, and CKD events occurred, respectively. Compared to the lowest quartile (reference), the hazard ratios (HR) associated with the highest quartile of METS-IR were 1.527 (95% confidence interval [CI]: 1.208-1.930, P for trend 0.001), 1.393 (0.865-2.243, > 0.05), 0.841 (0.682-1.038, > 0.05), 3.277 (2.645-4.060, < 0.001), 1.969 (1.752-2.214, < 0.001), and 1.020 (0.874-1.191, > 0.05) for CHD, stroke, all-cause mortality, diabetes, hypertension, and CKD, respectively. METS-IR, as a continuous variable, was significantly associated with the risk of incident CHD [HR, 95% CI: 1.106, 1.034-1.184], diabetes [1.524, 1.438-1.616], and hypertension [1.321, 1.265-1.380]. These associations were also independent of metabolic syndrome (METS) and remained unchanged in a subgroup of individuals without METS and/or diabetes.

CONCLUSIONS

Increasing levels of METS-IR were significantly associated with a greater risk of incident CHD, diabetes, and hypertension; therefore, this index can be a useful tool for capturing the risk of these clinical outcomes.

Triglyceride-glucose-waist circumference index predicts the incidence of cardiovascular disease in Korean populations: competing risk analysis of an 18-year prospective study

BACKGROUND

The triglyceride and glucose-waist circumference (TyG-WC) index demonstrated a strong association with insulin resistance, especially in Asian population. However, evidence on the association between TyG-WC index and the occurrence of cardiovascular disease (CVD) is limited. This study aimed to verify association between the TyG-WC index and the occurrence of CVD by considering all-cause mortality as a competing risk.

METHODS

The study included 7482 participants divided into four groups based on the TyG-WC index quartiles. Kaplan-Meier curves illustrated cumulative incidence rates of CVD and all-cause mortality during the follow-up period. Log-rank tests determined group differences. The Cox proportional hazard spline curve demonstrates the dose-dependent relationship between the TyG-WC index and incident CVD. Modified Cox regression (Fine and Gray) estimated hazard ratios (HRs) with 95% CIs for incident CVD, treating death as a competing risk. Death event after incident CVD was excluded from the death count.

RESULTS

During the median 15.94 year of follow-up period, a total of 691 (9.24%) new-onset CVD cases and 562 (7.51%) all-cause mortality cases were confirmed. Cox proportional hazard spline curves suggested that TyG-WC index exhibited a dose-dependent positive correlation with incident CVD. The cumulative incidence rate of CVD was significantly higher in the groups with higher TyG-WC index quartiles in Kaplan-Meier curves. The adjusted HR (95% CI) for incident CVD in Q2-Q4, compared with Q1, was 1.47 (1.12-1.93), 1.91 (1.44-2.54) and 2.24 (1.63-3.07), respectively. There was no significant association between TyG-WC index and all-cause mortality. Specifically, angina and stroke were significantly associated with the TyG-WC index, in contrast to myocardial infarction and peripheral artery disease.

CONCLUSIONS

The TyG-WC index was positively associated with incident CVD even considering all-cause mortality as a competing risk. Therefore, TyG-WC index may be a valuable marker for predicting the occurrence of CVD.

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.

Non-linear associations of HOMA2-IR with all-cause mortality in general populations: insights from NHANES 1999-2006

BACKGROUND

The association between homeostatic model assessment (HOMA2-IR) and mortality in obese and non-obese populations has not been clearly explained.

METHODS

A total of 7,085 individuals aged ≥ 20 years from the 1999-2006 National Health and Nutrition Examination Survey were included in the study. Study endpoints were all-cause and cardiovascular mortality. Multivariate Cox proportional hazards regression models with restricted cubic spline analysis were used for analysis.

RESULTS

In the study populations, a total of 1666 all-cause deaths and 555 cardiovascular (CV) deaths were recorded during a mean follow-up of 195.53 months. Notably, a significant difference in obesity was observed in the association between HOMA2-IR and mortality. After adjustment for multiple variables, HOMA2-IR was positively associated with all-cause mortality in all participants, in those with normal BMI, and in those with obesity. Conversely, tertile 2 of HOMA2-IR was associated with a lower risk of all-cause mortality in participants with obesity compared with tertile 1 (adjusted hazard ratio, 0.68; 95% confidence interval, 0.52-0.89; P = 0.005). Results from restricted cubic spline analysis showed a J-shaped association between HOMA2-IR and all-cause and CV mortality. In addition, a nonlinear U-shaped correlation with all-cause (P for nonlinear < 0.001) and CV (P for nonlinear = 0.002) mortality was observed in the population with obesity, with inflection points of HOMA2-IR identified at 1.85 and 1.75. Below the inflection point of 1.85, a negative relationship between HOMA2-IR and all-cause mortality was observed.

CONCLUSIONS

Elevated HOMA2-IR showed a notable correlation with increased risk of all-cause mortality. It was noteworthy that excessively reduced levels of insulin resistance showed a distinct association with increased mortality in individuals with obesity.

Longitudinal changes in body fat and metabolic complications in young people with perinatally acquired HIV

BACKGROUND

The role of body fat on metabolic complications remains poorly understood in young people living with perinatally acquired HIV (YPHIV).

OBJECTIVE

Our objective was to assess the association of changes in adiposity over 2 years with metabolic outcomes in YPHIV.

METHODS

The PHACS Adolescent Master Protocol (AMP) study enrolled YPHIV from 2007 to 2009 across 15 US sites, including Puerto Rico. We included YPHIV aged 7-19 years with body composition data assessed by whole-body dual-energy X-ray absorptiometry (DXA) at baseline and 2 years later. Metabolic outcomes included homeostatic model assessment of insulin resistance (HOMA-IR) and non-high-density lipoprotein cholesterol (non-HDL-C). We fitted linear regression models to assess the association of increase in body fat over 2 years with metabolic outcomes at years 2 and 3.

RESULTS

In all, 232 participants had a second DXA and either HOMA-IR or non-HDL-C measured at year 2. Participant characteristics at the first DXA were: age 12 years (9-14) [median (Q1-Q3)], 69% Black, and median CD4 count 714 cells/μL; 70% with HIV RNA <400 copies/mL. In adjusted analyses for every 1% increase in body fat from baseline to year 2, HOMA-IR was higher by 1.03-fold at year 3 (95% CI: 1.00, 1.05). We observed that for every 1% increase in body fat from baseline to year 2, non-HDL-C was 0.72 mg/dL higher at year 2 (95% CI: -0.04-1.49) and 0.81 mg/dL higher at year 3 (95% CI: -0.05-1.66).

CONCLUSIONS

Increases in adiposity over time may lead to downstream decreased insulin sensitivity and dyslipidaemia in YPHIV.

Estimated glucose disposal rate and risk of arterial stiffness and long-term all-acuse mortality: a 10-year prospective study

BACKGROUND

To assess the applicability of the association between estimated glucose disposal rate (eGDR) and all-cause mortality in the elderly population, and the mediating role of brachial-ankle pulse wave velocity (baPWV).

METHODS

This was a follow-up cohort study based on the cross-sectional survey of community-dwelling elderly. All participants in the study were included between September 2009 and June 2010, and the follow-up time was December 2020. Participants included 1862 Chinese community-dwelling elderly aged 60 years and above. Insulin resistance assessed by eGDR and arterial stiffness assessed by baPWV were the primary exposures of interest. Mortality, which was followed up until December 2020, was the primary outcome. Cox proportional hazards regression models were used to estimate the association of eGDR with mortality. The mediating effect of baPWV in this association was assessed by mediation analysis.

RESULTS

A total of 1826 participants with a mean age of 71.03 years old were included in the study. During the median follow-up of 10.75 years, 334 participants died. The adjusted HR comparing the highest versus the lowest eGDR quartile was 0.22 (95% CI 0.09 to 0.54; p<0.001) in the Cox proportional hazards model. The results of mediation analysis showed that baPWV had a significant mediation impact on the link between eGDR and all-cause mortality both as continuous or categorical variables.

CONCLUSION

eGDR is an independent predictor of all-cause mortality in the elderly population. baPWV partially mediated the association of eGDR and long-term all-cause mortality as a mediator factor.

Exploring the association between triglyceride-glucose index and thyroid function

BACKGROUND

Thyroid dysfunction is associated with abnormal glucose-insulin homeostasis, and the triglyceride-glucose (TyG) index has been recommended as a convenient surrogate of insulin resistance (IR). This study aimed to investigate the relationship between TyG and thyroid function in the US population.

METHODS

 We analyzed data from the National Health and Nutrition Examination Survey (NHANES) conducted from 2007 to 2012 in a cross-sectional manner. Aside from conventional thyroid parameters, our study evaluated the central sensitivity to thyroid hormones (THs) using the thyroid feedback quantile-based index (TFQI), thyrotropin resistance index (TT4RI), and thyrotropin index (TSHI). To evaluate peripheral sensitivity to THs, we calculated the ratio of free triiodothyronine (FT3) to free thyroxine (FT4) and the sum activity of peripheral deiodinases (SPINA-GD). In the 1848 adults, multivariable linear regression, subgroup, and interaction analyses were employed to estimate the association between TyG and thyroid parameters. The nonlinear relationship was addressed by smooth curve fittings and generalized additive models.

RESULTS

After adjusting covariates, we demonstrated a significant negative association between TyG and FT4 (β = - 0.57, p < 0.001), and a positive relationship between TyG and thyroid-stimulating hormone (β = 0.34, p = 0.037), as well as TgAb (β = 17.06, p = 0.005). Subgroup analysis indicated that the association between TyG and TgAb was more pronounced in the female subjects (β = 32.39, p < 0.001, p for interaction = 0.021). We also confirmed an inverse correlation between TyG and central sensitivity to THs, as assessed by TSHI and TT4RI (βTSHI = 0.12, p < 0.001; βTT4RI = 2.54, p = 0.023). In terms of peripheral sensitivity to THs, we found a significant positive correlation between TyG and FT3/FT4 (β = 0.03, p = 0.004), and SPINA-GD (β = 2.93, p = 0.004).

CONCLUSION

The present study established a noteworthy association between TyG and thyroid parameters, indicating a strong link between IR and thyroid dysfunction. Further investigations are warranted to validate these results.

Relationships of neck circumference and abdominal obesity with insulin resistance considering relative handgrip strength in middle-aged and older individuals

PURPOSE

This cross-sectional study evaluated how neck circumference (NC) influences the association between abdominal obesity (AO) and insulin resistance (IR) while considering relative handgrip strength (RHGS) in middle-aged and older people.

METHODS

Using data from the 2019 Korea National Health and Nutrition Examination Survey for 3804 Korean adults aged 40-80 years, AO (waist circumference [WC] ≥90 cm for men, ≥85 cm for women), large NC (sex-specific highest 5th quintile), weak RHGS (sex-specific 1st quintile of HGS/body mass index), and IR (homeostasis model assessment of IR [HOMA-IR] ≥2.5) were defined. A complex sample general linear model and logistic regression analyses were performed after adjusting for confounding factors.

RESULTS

As NC increased, the relationship between WC and HOMA-IR increased (p for interaction <0.001). In the group with AO, large NC, or both, the adjusted odds ratio (AOR) for IR increased in the group with weak RHGS than in the group with normal RHGS. In the group with normal NC, the AOR for IR in those with AO (vs. those without AO) was 3.3 (95% confidence interval, 2.6-4.3) even after controlling for RHGS; however, the AOR was 5.3 (95% confidence interval, 2.7-10.4) in the group with large NC. These relationships of WC, NC, and RHGS with IR were comparable across sex and age groups.

CONCLUSIONS

Large NC increased the association between AO and IR independent of RHGS and the relationships between large NC and AO and insulin resistance varied according to RHGS.

Baseline renal function and the risk of cancer among apparently healthy middle-aged adults

BACKGROUND

The association between mildly impaired renal function with all-site and site-specific cancer risk is not established. We aim to explore this association among apparently healthy adults.

METHODS

We followed 25,073 men and women, aged 40-79 years, free of cancer or cardiovascular disease at baseline who were screened annually in preventive healthcare settings. The estimated glomerular filtration rate (eGFR) was calculated using the CKD Epidemiology Collaboration equation (CKD-EPI) and classified into four mutually exclusive groups: <60, 60-74, 75-89, ≥90 (mL/min/1.73 m²). The primary outcome was all-site cancer while the secondary outcome was site-specific cancer. Cancer data was available from a national registry.

RESULTS

Mean age at baseline was 50 ± 8 years and 7973 (32 %) were women. During a median follow-up of 9 years (IQR 3-16) and 256,279 person years, 2045 (8.2 %) participants were diagnosed with cancer. Multivariable Cox model showed a 1.2 (95 %CI: 1.0-1.4 p = 0.05), 1.2 (95 %CI: 1.0-1.4 p = 0.02), and 1.4 (95 %CI: 1.1-1.7 p = 0.003) higher risk for cancer with eGFR of 75-89, 60-74, and < 60, respectively. Site-specific analysis demonstrated a 1.8 (95 %CI: 1.2-2.6 p = 0.004), 1.7 (95 %CI: 1.2-2.6 p = 0.004) and 2.2 (95 %CI: 1.3-3.6 p = 0.002) increased risk for prostate cancer with eGFR of 75-89, 60-74, and < 60, respectively. eGFR< 60 was associated with a 2.0 (95 %CI: 1.1-3.7 p = 0.03) and 3.7 (95 %CI: 1.1-13.1 p = 0.04) greater risk for melanoma and gynecological caner respectively.

CONCLUSIONS

CKD stage 2 and worse is independently associated with higher risk for cancer incidence, primarily prostate cancer. Early intervention and screening are warranted among these individuals in order to reduce cancer burden.

Predictive values of metabolic score for insulin resistance on risk of major adverse cardiovascular events and comparison with other insulin resistance indices among Chinese with and without diabetes mellitus: Results from the 4C cohort study

AIMS/INTRODUCTION

To investigate the relationship between the metabolic score for insulin resistance (METS-IR) index and major adverse cardiac events (MACEs) and to compare its ability to predict MACEs with other IR indices including homeostatic model assessment for IR (HOMA-IR) and triglyceride glucose (TyG) index-related parameters.

MATERIALS AND METHODS

We conducted a cohort study enrolling 7,291 participants aged ≥40 years. Binary logistic regression and restricted cubic splines were performed to determine the association between METS-IR and MACEs, and the receiver operating curve (ROC) was utilized to compare the predictive abilities of IR indices and to determine the optimal cut-off points.

RESULTS

There were 348 (4.8%) cases of MACEs during a median follow-up of 3.8 years. Compared with participants with a METS-IR in the lowest quartile, the multivariate-adjusted RRs and 95% CIs for participants with a METS-IR in the highest quartile were 1.47 (1.05-2.77) in all participants, 1.42 (1.18-2.54) for individuals without diabetes, and 1.75 (1.11-6.46) for individuals with diabetes. Significant interactions were found between the METS-IR and the risk of MACEs by sex in all participants and by age and sex in individuals without diabetes (all P values for interaction < 0.05). In the ROC analysis, the METS-IR had a higher AUC value than other indices for predicting MACEs in individuals with diabetes and had a comparable or higher AUC than other indices for individuals without diabetes.

CONCLUSIONS

The METS-IR can be an effective clinical indicator for identifying MACEs, as it had superior predictive power when compared with other IR indices in individuals with diabetes.

Development and validation of an insulin resistance model for a population without diabetes mellitus and its clinical implication: a prospective cohort study

Background

Insulin resistance (IR) is associated with diabetes mellitus, cardiovascular disease (CV), and mortality. Few studies have used machine learning to predict IR in the non-diabetic population.

Methods

In this prospective cohort study, we trained a predictive model for IR in the non-diabetic populations using the US National Health and Nutrition Examination Survey (NHANES, from JAN 01, 1999 to DEC 31, 2012) database and the Taiwan MAJOR (from JAN 01, 2008 to DEC 31, 2017) database. We analysed participants in the NHANES and MAJOR and participants were excluded if they were aged <18 years old, had incomplete laboratory data, or had DM. To investigate the clinical implications (CV and all-cause mortality) of this trained model, we tested it with the Taiwan biobank (TWB) database from DEC 10, 2008 to NOV 30, 2018. We then used SHapley Additive exPlanation (SHAP) values to explain differences across the machine learning models.

Findings

Of all participants (combined NHANES and MJ databases), we randomly selected 14,705 participants for the training group, and 4018 participants for the validation group. In the validation group, their areas under the curve (AUC) were all >0.8 (highest being XGboost, 0.87). In the test group, all AUC were also >0.80 (highest being XGboost, 0.88). Among all 9 features (age, gender, race, body mass index, fasting plasma glucose (FPG), glycohemoglobin, triglyceride, total cholesterol and high-density cholesterol), BMI had the highest value of feature importance on IR (0.43 for XGboost and 0.47 for RF algorithms). All participants from the TWB database were separated into the IR group and the non-IR group according to the XGboost algorithm. The Kaplan-Meier survival curve showed a significant difference between the IR and non-IR groups (p < 0.0001 for CV mortality, and p = 0.0006 for all-cause mortality). Therefore, the XGboost model has clear clinical implications for predicting IR, aside from CV and all-cause mortality.

Interpretation

To predict IR in non-diabetic patients with high accuracy, only 9 easily obtained features are needed for prediction accuracy using our machine learning model. Similarly, the model predicts IR patients with significantly higher CV and all-cause mortality. The model can be applied to both Asian and Caucasian populations in clinical practice.

Funding

Taichung Veterans General Hospital, Taiwan and Japan Society for the Promotion of Science KAKENHI Grant Number JP21KK0293.

Islet function changes of post-glucose-challenge relate closely to 15 years mortality of elderly men with a history of hyperglycemia

Aims

We aimed to investigate the relationship between islet function changes during a glucose challenge and 15-year mortality in elderly men.

Methods

Elderly men who did the oral glucose tolerance test in 2005 owing to an abnormal glucose history without diabetes were included. Changes in insulin resistance and secretion were evaluated using the homeostasis model assessment (HOMA) of fast, post-load, and ratios. Comparisons between the dead and the survival groups were analyzed using the Student's t-test (continuous variables) or χ2 test (Categorical variables). Single-factor logistic regression was used to identify the possible affecting factors. Multifactorial logistic regression was used to identify the independent risk factors in total population and in the subgroups. ROC curve was used to assess the predictive ability of risk factor and to determine the cut-off value.

Results

Of the 220 elderly men, 67 died according to 15-year retrospection. Age (OR = 1.243, P = 0.000), diastolic pressure (OR = 0.958, P = 0.027), and HOMA-IR (2 h/0 h) (OR = 1.040, P = 0.010) were independent risk factors for 15-year mortality. Subgroup analysis showed that HOMA-IR (2 h/0 h) was an obvious risk factor, especially for normal glucose tolerance (OR = 1.060, P = 0.030), age 60-70 years (OR = 1.068, P = 0.005), and hypertension (OR = 1.048, P = 0.013); HOMA-β (2 h/0 h) showed some protective effects in the impaired glucose regulation subgroup (OR = 0.779, P = 0.057). HOMA-IR (2 h/0 h) cut-off value was 15.

Conclusions

HOMA-IR (2 h/0 h) higher than 15 was an independent risk factor for 15-year mortality in elderly men with hyperglycemia history.

Bariatric surgery normalizes diabetes risk index by one month post-operation

AIM

The Diabetes risk index (DRI) is a composite of NMR-measured lipoproteins and branched chain amino acids predictive of diabetes mellitus development. Bariatric surgery is indicated in patients with severe obesity, many of whom are at high-risk for developing diabetes. Substantial weight loss occurs following bariatric surgery and sustained weight loss likely contributes to reductions in the development of diabetes and cardiovascular disease. However, some evidence suggests that bariatric surgical procedures themselves may contribute to reducing risk of these conditions independent of weight loss. We aimed to investigate DRI and its association with reductions in body weight and adiposity over one year following bariatric surgery.

METHODS

We examined 51 severely obese premenopausal women without diabetes. DRI, BMI, body weight and waist measurements were made before and at 1, 6 and 12 months after Roux-en-Y Gastric Bypass (RYGB) or Sleeve Gastrectomy. Values were compared to healthy women with normal BMI (18.5-24.9 kg/m2; n = 15).

RESULTS

Non-diabetic women with severe obesity (BMI 44.7 ± 6.2 kg/m2) exhibited significantly elevated DRI scores prior to surgery versus controls (35 [26, 39] vs 12 [1, 20]; p < 0.0001). At 1 month after surgery, BMI decreased 5.1 ± 1.1 kg/m2, but DRI decreased so that it no longer differed from that of normal BMI controls (1.9 [1, 17] vs control 12 [1, 20]; p = 0.35). Subjects continued to lose weight, whereas DRI remained similar, throughout follow-up with DRI 1.0 [1, 7] at 12 months. Changes in DRI did not correlate with changes in BMI, body weight or waist circumference at any time during follow-up. There was no difference in change in DRI between surgical procedures or pre-operative metabolic syndrome status.

CONCLUSIONS

Our analysis of DRI scores supports the capacity of bariatric surgery to reduce risk of developing diabetes in severely obese individuals. Our findings suggest that bariatric surgical techniques may have inherent effects that improve cardiometabolic risk independent of reductions in body weight or adiposity.

Hyperinsulinemia and plasma glucose level independently associated with all-cause and cardiovascular mortality in Chinese people without diabetes-A post-hoc analysis of the 30-year follow-up of Da Qing diabetes and IGT study

AIMS

We aimed to characterize the effect of insulin resistance and plasma glucose on all-cause and cardiovascular disease (CVD) death.

METHODS

A total of 462 individuals without diabetes in the original Da Qing Diabetes and IGT Study were enrolled in the present analysis, and further divided into G1 (low insulin low glucose), G2 (high insulin low glucose), G3 (low insulin high glucose) and G4 (high insulin high glucose) groups according to medians of glucose and insulin level at baseline. The all-cause and CVD death were assessed from 1986 to 2016.

RESULTS

During the 30-year follow-up, compared with G1, G2, G3, and G4 groups were all at increased death risk after adjusting covariates. G2 and G3 were associated with similar risks in both all-cause (G2: HR 1.65, 95%CI 1.02-2.67; G3: HR 1.76, 95%CI 1.11-2.81) and CVD death (G2: HR 2.03, 95%CI 1.01-4.05; G3: HR 1.85, 95%CI 0.93-3.68). The highest risk was observed in G4 (all-cause death: HR 2.32, 95%CI 1.45-3.69; CVD death: HR 2.68, 95%CI 1.35-5.29).

CONCLUSIONS

In this post-hoc study, participants with either high glucose or high insulin were related to increased risk of mortality, implying that strategies targeting eliminating both hyperglycemia and hyperinsulinemia may favor the long-term outcomes.

Evaluating Triglyceride and Glucose Index as a Simple and Easy-to-Calculate Marker for All-Cause and Cardiovascular Mortality

OBJECTIVE

The triglyceride and glucose (TyG) index is a useful marker of insulin resistance and is a predictor of several metabolic diseases. The aim of this study was to evaluate the association between the TyG index and all-cause or cardiovascular mortality using a large population-based cohort study database.

METHODS

A total of 255,508 subjects in the Kangbuk Samsung Health Study cohort were enrolled. Cox proportional hazards models were used to analyze the risk of mortality.

RESULTS

During a median 5.7-year follow-up, the cumulative all-cause and cardiovascular mortality was 0.47% and 0.07%. There was a nonlinear relationship between the TyG index and death, and moving from moderate to high, the TyG index levels were associated with an increase in the risk of death. The hazard ratio (HR) for all-cause and cardiovascular mortality of the TyG index was 1.21 [95% confidence interval (CI) 1.14-1.28] and 1.45 (95% CI 1.26-1.66) in the unadjusted model, respectively. After adjustment for covariates, the association between the TyG index and all-cause and cardiovascular mortality was attenuated. In the multivariable-adjusted model, the TyG index was associated with an elevated risk of all-cause mortality in women (HR 1.13, 95% CI 1.02-1.26) and a decreased risk in men (HR 0.92, 95% CI 0.85-0.99). The association between cardiovascular mortality and the TyG index was not statistically significant among either men or women in the multivariable-adjusted model.

CONCLUSIONS

The TyG index in a young, relatively healthy, population is associated with an elevated risk of all-cause and cardiovascular mortality. This association between the TyG index and all-cause mortality persists in women after multivariable adjustment.

The insulin sensitivity Mcauley index (MCAi) is associated with 40-year cancer mortality in a cohort of men and women free of diabetes at baseline

Background

The association between insulin resistance and cancer-mortality is not fully explored. We investigated the association between several insulin sensitivity indices (ISIs) and cancer-mortality over 3.5 decades in a cohort of adult men and women. We hypothesized that higher insulin resistance will be associated with greater cancer-mortality risk.

Methods

A cohort of 1,612 men and women free of diabetes during baseline were followed since 1979 through 2016 according to level of insulin resistance (IR) for cause specific mortality, as part of the Israel study on Glucose Intolerance, Obesity and Hypertension (GOH). IR was defined according to the Mcauley index (MCAi), calculated by fasting insulin and triglycerides, the Homeostatic Model Assessment (HOMA), the Matsuda Insulin Sensitivity Index (MISI), and the Quantitative Insulin Sensitivity Check Index (QUICKI), calculated by plasma glucose and insulin.

Results

Mean age at baseline was 51.5 ± 8.0 years, 804 (49.9%) were males and 871 (54.0%) had prediabetes. Mean follow-up was 36.7±0.2 years and 47,191 person years were accrued. Cox proportional hazard model and competing risks analysis adjusted for age, sex, country of origin, BMI, blood pressure, total cholesterol, smoking and glycemic status, revealed an increased risk for cancer-mortality, HR = 1.5 (95% CI: 1.1–2.0, p = 0.005) for the MCAi Q₁ compared with Q_2-4. No statistically significant associations were observed between the other ISIs and cancer-mortality.

Conclusion

The MCAi was independently associated with an increased risk for cancer-mortality in adult men and women free of diabetes and should be further studied as an early biomarker for cancer risk.

Linking Mitochondrial Function to Insulin Resistance: Focusing on Comparing the Old and the Young

Long-term intake of high-energy diet can lead to decreased insulin sensitivity and even insulin resistance, eventually leading to diabetes. Diabetes often occurs in middle-aged and elderly people. However, there is growing evidence that the incidence rate of young body is increasing over the years. This means that insulin resistance can be caused by excessive energy intake in both young and old people. In this study, high-fat diet (HFD) and normal diet were fed to rats of elderly experimental group (EE), elderly control group (EC), young experimental group (YE), and young control group (YC), respectively, for 8 weeks, by which insulin resistance model was obtained. Insulin sensitivity was measured, histopathology changes in liver and skeletal muscle tissues were observed, and mitochondrial fusion and division and cell senescence were detected in four groups of rats. The results showed that both young and elderly rats developed significant insulin resistance, fat deposition, decline of mitochondrial function and mitochondrial biosynthesis in liver and skeletal muscle, and cell aging after HFD feeding. In addition, the degree of mitochondrial dysfunction and aging in young rats was similar to that of aged rats fed a normal diet after HFD. This experiment provides a reference for an in-depth study of the regulatory mechanisms of cellular energy metabolism in this state.

Association Between a Novel Metabolic Score for Insulin Resistance and Mortality in People With Diabetes

BACKGROUND

Growing studies have shown that insulin resistance (IR) is associated with poor prognoses among patients with diabetes, whereas the association between IR and mortality has not been determined. Hence we aimed to evaluate the associations between IR and all-cause, cardiovascular diseases (CVDs) and cancer-related mortality in patients with diabetes.

METHODS

We enrolled 2,542 participants with diabetes with an average age of 57.12 ± 0.39 years and 52.8% men from the 1999-2014 National Health and Nutrition Examination Survey (NHANES 1999-2014). A novel metabolic score for insulin resistance (METS-IR) was considered as alternative marker of IR. Mortality data were obtained from the National Death Index records and all participants were followed up until December 31, 2015. Cox proportional hazards regression, restricted cubic spline and Kaplan-Meier survival curves were performed to evaluate the associations between METS-IR and all-cause and cause-specific mortality in patients with diabetes.

RESULTS

During 17,750 person-years of follow-up [median (months), 95% CI: 90, 87-93], 562 deaths were documented, including 133 CVDs-related deaths and 90 cancer-related deaths. Multivariate Cox regression showed that compared with Quintile 1 (METS-IR ≤ 41), METS-IR in Quintile 2, 3, and 4 was all associated with all-cause mortality (Q2 vs. Q1: HR 0.65, 95% CI 0.49-0.87, P = 0.004; Q3 vs. Q1: HR 0.69, 95% CI 0.50-0.96, P = 0.029; Q4 vs. Q1: HR 0.57, 95% CI 0.36-0.91, P = 0.019; respectively). Restricted cubic spline indicated that METS-IR was non-linearly associated with all-cause and CVDs-related mortality. Threshold effect analyses determined that threshold values of METS-IR for all-cause and CVDs-related mortality were both 33.33. Only METS-IR below the threshold was negatively associated with all-cause and CVDs-related mortality (HR 0.785, 95% CI 0.724-0.850, P < 0.001; HR 0.722, 95% CI 0.654-0.797, P < 0.001; respectively). Sensitivity analyses showed that when excluding participants who died within 1 years of follow-up, the results of threshold effect analyses remained consistent, whereas excluding participants with CVDs, METS-IR below the threshold was only negatively correlated with all-cause mortality. Subgroup analyses indicated that for all-cause mortality, the results were still stable in all subgroups except newly diagnosed diabetes, but for CVDs-related mortality, the association persisted only in participants who were ≤ 65 years, male, White, non-White, already diagnosed diabetes, or uesd oral drugs, insulin, insulin sensitizing drugs.

CONCLUSION

METS-IR was non-linearly associated with all-cause and CVDs-related mortality in patients with diabetes, and METS-IR below the threshold was negatively associated with all-cause and CVDs-related mortality.

Association between Relative Handgrip Strength and Insulin Resistance in Korean Elderly Men without Diabetes: Findings of the 2015 Korea National Health Nutrition Examination Survey

BACKGROUND

Evidence regarding the association between handgrip strength (HGS) and insulin resistance in a non-diabetic population is scarce. This study aimed to investigate the association between relative HGS and insulin resistance in older men without diabetes, using a representative sample of the Korean male population.

METHODS

The study population comprised 206 participants aged 65-80 years, selected from the 2015 Korea National Health and Nutrition Examination Survey. Insulin resistance was defined as the upper tertile of the homeostatic model assessment of insulin resistance (HOMA-IR). Odds ratios and 95% confidence intervals for insulin resistance were assessed using multiple logistic regression analyses after adjusting for confounding variables.

RESULTS

The prevalence of insulin resistance decreased with increasing relative HGS. The prevalence in the T1, T2, and T3 groups was 46.0%, 32.2%, and 26.4%, respectively. Compared with the individuals in the highest tertile of relative HGS, the odds ratio (95% confidence interval) for insulin resistance in individuals in the lowest quartile was 2.82 (1.10-7.21) after adjusting for age, smoking, alcohol consumption, aerobic exercise, resistance exercise, systolic blood pressure, total cholesterol, residential area, household income, and education level.

CONCLUSION

Lower relative HGS was inversely associated with an increased risk of insulin resistance in older Korean men without diabetes. In clinical practice, relative HGS, which is a simple and inexpensive tool, could be a useful measure for identifying older men with insulin resistance. Moreover, these findings suggest that muscle strengthening exercises should be considered to reduce insulin resistance and increase insulin sensitivity.

Emerging Glycation-Based Therapeutics-Glyoxalase 1 Inducers and Glyoxalase 1 Inhibitors

The abnormal accumulation of methylglyoxal (MG) leading to increased glycation of protein and DNA has emerged as an important metabolic stress, dicarbonyl stress, linked to aging, and disease. Increased MG glycation produces inactivation and misfolding of proteins, cell dysfunction, activation of the unfolded protein response, and related low-grade inflammation. Glycation of DNA and the spliceosome contribute to an antiproliferative and apoptotic response of high, cytotoxic levels of MG. Glyoxalase 1 (Glo1) of the glyoxalase system has a major role in the metabolism of MG. Small molecule inducers of Glo1, Glo1 inducers, have been developed to alleviate dicarbonyl stress as a prospective treatment for the prevention and early-stage reversal of type 2 diabetes and prevention of vascular complications of diabetes. The first clinical trial with the Glo1 inducer, trans-resveratrol and hesperetin combination (tRES-HESP)-a randomized, double-blind, placebo-controlled crossover phase 2A study for correction of insulin resistance in overweight and obese subjects, was completed successfully. tRES-HESP corrected insulin resistance, improved dysglycemia, and low-grade inflammation. Cell permeable Glo1 inhibitor prodrugs have been developed to induce severe dicarbonyl stress as a prospective treatment for cancer-particularly for high Glo1 expressing-related multidrug-resistant tumors. The prototype Glo1 inhibitor is prodrug S-p-bromobenzylglutathione cyclopentyl diester (BBGD). It has antitumor activity in vitro and in tumor-bearing mice in vivo. In the National Cancer Institute human tumor cell line screen, BBGD was most active against the glioblastoma SNB-19 cell line. Recently, potent antitumor activity was found in glioblastoma multiforme tumor-bearing mice. High Glo1 expression is a negative survival factor in chemotherapy of breast cancer where adjunct therapy with a Glo1 inhibitor may improve treatment outcomes. BBGD has not yet been evaluated clinically. Glycation by MG now appears to be a pathogenic process that may be pharmacologically manipulated for therapeutic outcomes of potentially important clinical impact.

Insulin Resistance and Cardiometabolic Risk Profile Among Nondiabetic American Young Adults: Insights From NHANES

BACKGROUND

The burden of insulin resistance (IR) among young American adults has not been previously assessed. We evaluated (1) the prevalence and trends of IR and cardiometabolic risk factors and (2) the association between measures of adiposity and IR among adults 18 to 44 years of age without diabetes and preexisting cardiovascular disease.

METHODS

Cross-sectional survey data from six consecutive National Health and Nutrition Examination Survey (2007-2008 to 2017-2018) cycles were analyzed. IR was defined by the homeostatic model assessment for IR (HOMA-IR) of ≥2.5. The temporal trends of IR, cardiometabolic risk factors, and the relationship between IR and measures of adiposity were assessed using multivariable-adjusted regression models.

RESULTS

Among 6247 young adults 18 to 44 years of age, the prevalence of IR was 44.8% (95% CI: 42.0%-47.6%) in 2007-2010 and 40.3% (95% CI: 36.4%-44.2%) in 2015-2018 (P for trend = 0.07). There was a modest association of HOMA-IR with higher body mass index (BMI), waist circumference, total lean fat mass, and total and localized fat mass (all Ps < 0.001). Participants with IR had a higher prevalence of hypertension [31.3% (95% CI: 29.2%-33.5%) vs 14.7% (95% CI: 13.2%-16.2%)], hypercholesterolemia [16.0% (95% CI: 12.4%-19.5%) vs 7.0% (95% CI: 5.8%-8.5%)], obesity [56.6% (95% CI: 53.9%-59.3%) vs 14.7% (95% CI: 13.0%-16.5%)], and poor physical activity levels [18.3% (95% CI: 16.4%-20.2%) vs 11.7% (95%CI: 10.3-13.1%)] compared to participants without IR (all Ps < 0.05).

CONCLUSIONS

Four-in-10 young American adults have IR, which occurs in a cluster with cardiometabolic risk factors. Nearly half of young adults with IR are nonobese. Screening efforts for IR irrespective of BMI may be required.

Lower B-type natriuretic peptide levels predict left ventricular concentric remodelling and insulin resistance

Aims

Natriuretic peptides have reportedly been associated with cardiac hypertrophy and insulin resistance; however, it has not been established if B‐type natriuretic peptide (BNP) is associated with either insulin resistance or cardiac remodelling in a population with normal plasma BNP levels. We investigated the relationship among plasma BNP levels, insulin resistance, and left ventricular (LV) remodelling in a population with normal physiological plasma BNP levels.

Methods and results

Among 1632 individuals who participated in annual health checks between 2005 and 2008 in Arita‐cho, Saga, Japan, 675 individuals [median (interquartile range) for age 62 (51–69) years; 227 men (34%)] with LV ejection fraction 50% and BNP level <35 pg/mL were enrolled in this study. Insulin resistance was assessed using homeostatic model assessment of insulin resistance (HOMA‐IR). LV geometry, including LV concentric remodelling, was classified based on relative wall thickness (RWT) and LV mass index values derived from echocardiographic findings. Factors associated with insulin resistance and LV geometry were investigated using multiple logistic regression analysis. Tertiles of BNP were inversely associated with HOMA‐IR [1st tertile, 1.33 (0.76–1.74); 2nd tertile, 1.05 (0.72–1.59); 3rd tertile, 0.95 (0.66–1.58), P = 0.005]. Lower BNP was associated with the prevalence of insulin resistance, defined as HOMA‐IR ≥1.37, even after full multivariate adjustment [1 SD increment in BNP = adjusted odds ratio (aOR) 0.740; 95% confidence interval (CI) 0.601–0.912; P = 0.005]. LV concentric remodelling (RWT >0.42; LV mass index ≤115 g/m² in men and ≤95 g/m² in women) was observed in 107 (16%) participants, while normal LV geometry (RWT ≤0.42; LV mass index ≤115 g/m² in men and ≤95 g/m² in women) was seen in 423 (63%), and LV hypertrophy (LV mass index >115 g/m² in men and >95 g/m² in women) in 145 (21%). Both low BNP level and higher insulin resistance were independently linked to LV concentric remodelling after multivariate adjustment (1 SD increment in BNP = aOR 0.714, 95% CI 0.544–0.938, P = 0.015; HOMA‐IR ≥ 1.37 vs. <1.37: aOR 1.694, 95% CI 1.004–2.857, P = 0.048, respectively).

Conclusions

Lower BNP levels are linked to either insulin resistance or LV concentric remodelling in a population with normal plasma BNP levels, suggesting that participants with lower natriuretic peptide level might be vulnerable to the development of metabolic disorders and LV morphological abnormalities.

The association between triglyceride-glucose index, cardio-cerebrovascular diseases, and death in Korean adults: A retrospective study based on the NHIS-HEALS cohort

BACKGROUND

The triglyceride-glucose (TyG) index is a reliable indicator of insulin resistance. We aimed to investigate the TyG index in relation to cardio-cerebrovascular diseases (CCVDs and mortality.

METHODS

This retrospective study included 114,603 subjects. The TyG index was categorized into four quartiles by sex: Q1, <8.249 and <8.063; Q2, 8.249‒<8.614 and 8.063‒<8.403; Q3, 8.614‒< 8.998 and 8.403‒<8.752; and Q4, ≥8.998 and ≥8.752, in men and women, respectively. To calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the primary outcomes (CCVDs and all-cause mortality) and secondary outcomes (cardiovascular diseases [CVDs], cerebrovascular diseases [CbVDs], CCVD-related deaths, or all-cause deaths), Cox proportional hazards regression models were adopted.

RESULTS

Compared to Q1, the HRs (95% CIs) for the primary outcomes of Q2, Q3, and Q4 were 1.062 (0.981‒1.150), 1.110 (1.024-1.204), and 1.151 (1.058-1.252) in men and 1.099 (0.986-1.226), 1.046 (0.938-1.166), and 1.063 (0.954-1.184) in women, respectively, after adjusted for age, smoking status, drinking status, physical activity, body mass index, systolic blood pressure, low-density lipoprotein cholesterol, economic status, and anti-hypertensive medications. Fully adjusted HRs (95% CIs) for CVDs of Q2, Q3, and Q4 were 1.114 (0.969-1.282), 1.185 (1.031-1.363), and 1.232 (1.068-1.422) in men and 1.238 (1.017-1.508), 1.183 (0.971-1.440), and 1.238 (1.018-1.505) in women, respectively. The adjusted HRs (95% CIs) for ischemic CbVDs of Q2, Q3, and Q4 were 1.005 (0.850-1.187), 1.225 (1.041-1.441), and 1.232 (1.039-1.460) in men and 1.040 (0.821-1.316), 1.226 (0.981-1.532), and 1.312 (1.054-1.634) in women, respectively, while the TyG index was negatively associated with hemorrhagic CbVDs in women but not in men. The TyG index was not significantly associated with CCVD-related death or all-cause death in either sex.

CONCLUSIONS

Elevated TyG index was positively associated with the primary outcomes (CCVDs and all-cause mortality) in men and predicted higher risk of CVDs and ischemic CbVDs in both sexes.

Insulin resistance-related differences in the relationship between left ventricular hypertrophy and cardiorespiratory fitness in hypertensive Black sub-Saharan Africans

BACKGROUND

Left ventricular hypertrophy (LVH) is associated with impaired cardiorespiratory fitness (CRF), a surrogate marker of poor outcome. Insulin resistance (IR) plays a central role in all stages of cardiovascular disease continuum. This study evaluates IR-related differences in the relationship between left ventricular mass (LVM) and CRF in asymptomatic newly diagnosed hypertensive Black sub-Saharan Africans.

METHODS

In this cross-sectional observational study, 126 asymptomatic newly diagnosed hypertensive participants (50.5 ± 9.5 years) underwent comprehensive resting transthoracic echocardiographic examination and maximal incremental cardiopulmonary exercise test (CPET). CRF was estimated in maximal oxygen uptake (VO2max). CPET results were compared between participants with and without LVH. Multivariate analysis examined the influence of IR on the observed differences.

RESULTS

Those with LVH had lower VO2max (15.7 ± 5.5 mL min^-1 kg^-1 vs. 18.4 ± 3.7 mL min^-1 kg^-1; P = 0.001) than those without LVH. In patients with IR, LVM (r = -0.261, P = 0.012), LVM indexed to body surface area (LVMIbsa; r = -0.229, P = 0.027), and LVM indexed to height to an allometric power of 2.7 (LVMIh^2.7; r = -0.351, P = 0.001), and VO2max were negatively correlated. In hypertensive patients without IR, these same parameters and VO2max have no significant correlation. Body mass index (BMI), LVM, and LVMIbsa emerged as independent determinants of VO2max, explaining 46.9% of its variability (overall P = 0.001) in IR participants, a relationship not found in participants without IR.

CONCLUSIONS

IR may participate in the deterioration of CRF associated with LVH. Measures to improve insulin sensitivity should be considered for improving CRF and therefore the prognosis of insulin-resistant hypertensive patients. Targeting IR in hypertensive patients with LVH could improve prognosis.

Current trends in epidemiology of cardiovascular disease and cardiovascular risk management in type 2 diabetes

With the advances in diabetes care, the trend of incident cardiovascular disease (CVD) in patients with type 2 diabetes mellitus (T2DM) has been decreasing over past decades. However, given that CVD is still a major cause of death in patients with diabetes and that the risk of CVD in patients with T2DM is more than twice that in those without DM, there are still considerable challenges to the prevention of CVD in diabetes. Accordingly, there have been several research efforts to decrease cardiovascular (CV) risk in T2DM. Large-scale genome-wide association studies (GWAS) and clinical cohort studies have investigated the effects of factors, such as genetic determinants, hypoglycaemia, and insulin resistance, on CVD and can account for the unexplained CV risk in T2DM. Lifestyle modification is a widely accepted cornerstone method to prevent CVD as the first-line strategy in T2DM. Recent reports from large CV outcome trials have proven the positive CV effects of sodium-glucose cotransporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RAs) in patients with high CVD risk. Overall, current practice guidelines for the management of CVD in T2DM are moving from a glucocentric strategy to a more individualised patient-centred approach. This review will discuss the current epidemiologic trends of CVD in T2DM and the risk factors linking T2DM to CVD, including genetic contribution, hypoglycaemia, and insulin resistance, and proper care strategies, including lifestyle and therapeutic approaches.

Reversal of Insulin Resistance in Overweight and Obese Subjects by trans-Resveratrol and Hesperetin Combination-Link to Dysglycemia, Blood Pressure, Dyslipidemia, and Low-Grade Inflammation

The dietary supplement, trans-resveratrol and hesperetin combination (tRES-HESP), induces expression of glyoxalase 1, countering the accumulation of reactive dicarbonyl glycating agent, methylglyoxal (MG), in overweight and obese subjects. tRES-HESP produced reversal of insulin resistance, improving dysglycemia and low-grade inflammation in a randomized, double-blind, placebo-controlled crossover study. Herein, we report further analysis of study variables. MG metabolism-related variables correlated with BMI, dysglycemia, vascular inflammation, blood pressure, and dyslipidemia. With tRES-HESP treatment, plasma MG correlated negatively with endothelial independent arterial dilatation (r = -0.48, p < 0.05) and negatively with peripheral blood mononuclear cell (PBMC) quinone reductase activity (r = -0.68, p < 0.05)-a marker of the activation status of transcription factor Nrf2. For change from baseline of PBMC gene expression with tRES-HESP treatment, Glo1 expression correlated negatively with change in the oral glucose tolerance test area-under-the-curve plasma glucose (ΔAUGg) (r = -0.56, p < 0.05) and thioredoxin interacting protein (TXNIP) correlated positively with ΔAUGg (r = 0.59, p < 0.05). Tumor necrosis factor-α (TNFα) correlated positively with change in fasting plasma glucose (r = 0.70, p < 0.001) and negatively with change in insulin sensitivity (r = -0.68, p < 0.01). These correlations were not present with placebo. tRES-HESP decreased low-grade inflammation, characterized by decreased expression of CCL2, COX-2, IL-8, and RAGE. Changes in CCL2, IL-8, and RAGE were intercorrelated and all correlated positively with changes in MLXIP, MAFF, MAFG, NCF1, and FTH1, and negatively with changes in HMOX1 and TKT; changes in IL-8 also correlated positively with change in COX-2. Total urinary excretion of tRES and HESP metabolites were strongly correlated. These findings suggest tRES-HESP counters MG accumulation and protein glycation, decreasing activation of the unfolded protein response and expression of TXNIP and TNFα, producing reversal of insulin resistance. tRES-HESP is suitable for further evaluation for treatment of insulin resistance and related disorders.

Dual effects of insulin resistance on mortality and function in non-diabetic older adults: findings from the Toledo Study of Healthy Aging

Insulin signalling declines with increasing age and impacts skeletal muscle function and longevity in animal models. Our aim was to assess the relationships between insulin resistance (IR) and frailty and mortality in a unique community-dwelling cohort of older people. 991 non-diabetic subjects from the Toledo Study of Healthy Ageing (TSHA) cohort were included. IR was estimated by the homeostasis model assessment index (HOMA-IR) at baseline while frailty was determined by frailty phenotype (FP) and Frailty Trait Scale (FTS) at baseline and after 5-year follow-up. Deaths were also determined. Multivariate regression models were used to analyze the effects of HOMA-IR on outcomes. Age, gender, BMI, education level, cardio- and cerebro-vascular disease, glomerular filtration rate, and disability were included as potential confounding variables in progressive adjustment models. IR determined as increasing log HOMA-IR was inversely associated with risk of mortality. The association remained significant for all adjustment models (HR: 0.64-0.69). When we analyzed survival curves, the higher the HOMA-IR tertile, the lower the mortality rate (highest vs lowest tertile, p = 0.0082). In contrast, IR increased the risk of incident frailty determined by FP (OR 1.81 [1.14-2.87]) as well as deterioration of frailty status determined by worsening in FTS score (OR 1.28 [1.01-1.63]) at 5-year follow-up. In non-diabetic older subjects, IR significantly increases the risk for frailty and functional decline but decreased the risk of death at 5-year follow-up. This finding raises the need of assessing the effect of biomarkers on different outcomes before establishing their role as biomarkers of aging.

Glucodensities: A new representation of glucose profiles using distributional data analysis

Biosensor data have the potential to improve disease control and detection. However, the analysis of these data under free-living conditions is not feasible with current statistical techniques. To address this challenge, we introduce a new functional representation of biosensor data, termed the glucodensity, together with a data analysis framework based on distances between them. The new data analysis procedure is illustrated through an application in diabetes with continuous-time glucose monitoring (CGM) data. In this domain, we show marked improvement with respect to state-of-the-art analysis methods. In particular, our findings demonstrate that (i) the glucodensity possesses an extraordinary clinical sensitivity to capture the typical biomarkers used in the standard clinical practice in diabetes; (ii) previous biomarkers cannot accurately predict glucodensity, so that the latter is a richer source of information and; (iii) the glucodensity is a natural generalization of the time in range metric, this being the gold standard in the handling of CGM data. Furthermore, the new method overcomes many of the drawbacks of time in range metrics and provides more in-depth insight into assessing glucose metabolism.

Whole-life body composition trajectory and longevity: role of insulin

The present study assessed the body composition trajectory of rats (N = 96) placed into 5 groups according to lifespan, using dual-energy x-ray absorptiometry every 6 months until end-of-life. A striking linearity between lifespan and bone mass percentage (not absolute bone mass) was observed. Long-lived rats show a higher bone mass percentage with a delayed insulin rise to a similar peak level as short-lived counterparts, followed by insulin declines and bone mass loss. Decreasing insulin after streptozotocin (STZ) injection caused a rapid bone mass loss (-10.5%) with a decreased 5-day survival rate to 35% in old rats (20 months). Insulin replacement to STZ-injected rats completely blocked bone mass loss and increased the survival rate to 71%. Normal old rats (20 months) had faster lean mass loss despite greater myofiber regeneration (centronucleation) compared with the young rats (4 months). Increased CD68⁺ and CD163⁺ cell infiltration into insulin-depleted muscle suggests a bone marrow cell exhaustion by aging muscle. Bone produces stem cells and phagocytes to continuously rejuvenate peripheral tissues. Our data suggests that aging and unsustainable life is associated with development of disproportionality between bone and the growing body size, partly due to insulin reversal from hyperinsulinemia during late life.

Investigating the relationship between insulin resistance and adipose tissue in a randomized Tehrani population

OBJECTIVES

Insulin resistance is the most common metabolic change associated with obesity. The present study aimed to investigate the relationship between insulin resistance and body composition especially adipose tissue in a randomized Tehrani population.

METHODS

This study used data of 2,160 individuals registered in a cross-sectional study on were randomly selected from among subjects who were referred to nutrition counseling clinic in Tehran, from April 2016 to September 2017. Insulin resistance was calculated by homeostasis model assessment formula. The odds ratio (95% CI) was calculated using logistic regression models.

RESULTS

The mean age of the men was 39 (±10) and women were 41 (±11) (the age ranged from 20 to 50 years). The risk of increased HOMA-IR was 1.03 (95% CI: 1.01-1.04) for an increase in one percent of Body fat, and 1.03 (95% CI: 1.00-1.05) for an increase in one percent of Trunk fat. Moreover, the odds ratio of FBS for an increase in one unit of Body fat percent and Trunk fat percent increased by 1.05 (adjusted odds ratio [95% CI: 1.03, 1.06]) and 1.05 (95% CI: 1.02, 1.08). Also, the risk of increased Fasting Insulin was 1.05 (95% CI: 1.03-1.07) for an increase in one unit of Body fat percent, and 1.05 (95% CI: 1.02-1.08) for an increase in one unit of Trunk fat percent.

CONCLUSIONS

The findings of the present study showed that there was a significant relationship between HOMA-IR, Fasting blood sugar, Fasting Insulin, and 2 h Insulin with percent of Body fat, percent of Trunk fat.

Insulin resistance, diabetic kidney disease, and all-cause mortality in individuals with type 2 diabetes: a prospective cohort study

BACKGROUND

It is unclear whether insulin resistance (IR) contributes to excess mortality in patients with type 2 diabetes independent of diabetic kidney disease (DKD), which is strongly associated with IR and is a major risk factor for cardiovascular disease (CVD), the main cause of death in these individuals. We tested this hypothesis in patients with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events Italian Multicentre Study.

METHODS

This observational, prospective, cohort study enrolled 15,773 patients with type 2 diabetes attending 19 Italian Diabetes Clinics in 2006-2008. Insulin sensitivity was assessed as estimated glucose disposal rate (eGDR), which was validated against the euglycaemic-hyperinsulinemic clamp technique. Vital status on October 31, 2015, was retrieved for 15,656 patients (99.3%). Participants were stratified by eGDR tertiles from T1 (≥ 5.35 mg/kg/min) to T3 (≤ 4.14 mg/kg/min, highest IR).

RESULTS

CVD risk profile was worse in T2 and T3 vs T1. eGDR tertiles were independently associated with micro- and macroalbuminuria and the albuminuric DKD phenotypes (albuminuria with preserved or reduced estimated glomerular filtration rate [eGFR]) as well as with eGFR categories or the nonalbuminuric DKD phenotype. Over a 7.4-year follow-up, unadjusted death rates and mortality risks increased progressively across eGDR tertiles, but remained significantly elevated after adjustment only in T3 vs T1 (age- and gender- adjusted death rate, 22.35 vs 16.74 per 1000 person-years, p < 0.0001, and hazard ratio [HR] adjusted for multiple confounders including DKD, 1.140 [95% confidence interval [CI], 1.049-1.238], p = 0.002). However, eGDR was independently associated with mortality in participants with no DKD (adjusted HR, 1.214 [95% CI, 1.072-1.375], p = 0.002) and in those with nonalbuminuric DKD (1.276 [1.034-1.575], p = 0.023), but not in those with the albuminuric DKD phenotypes. Moreover, the association was stronger in males and in younger individuals and was observed in those without but not with prior CVD, though interaction was significant only for age.

CONCLUSIONS

The proxy of insulin sensitivity eGDR predicts all-cause mortality in type 2 diabetes, independent of confounders including DKD. However, the impact of IR in individuals with albuminuric DKD may be mediated by its relationship with albuminuria.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT00715481, retrospectively registered 15 July 2008.

Dicarbonyl stress, protein glycation and the unfolded protein response

The reactive dicarbonyl metabolite, methylglyoxal (MG), is increased in obesity and diabetes and is implicated in the development of insulin resistance, type 2 diabetes mellitus and vascular complications of diabetes. Dicarbonyl stress is the metabolic state of abnormal high MG concentration. MG is an arginine-directed glycating agent and precursor of the major advanced glycation endproduct, arginine-derived hydroimidazolone MG-H1. MG-H1 is often formed on protein surfaces and an uncharged hydrophobic residue, inducing protein structural distortion and misfolding. Recent studies indicate that dicarbonyl stress in human endothelial cells and fibroblasts in vitro induced a proteomic response consistent with activation of the unfolded protein response (UPR). The response included: increased abundance of heat shock proteins and ubiquitin ligases catalysing the removal of proteins with unshielded surface hydrophobic patches and formation of polyubiquitinated chains to encapsulate misfolded proteins; and increased low grade inflammation. Activation of the UPR is implicated in insulin resistance. An effective strategy to counter increased MG is inducing increased expression of glyoxalase-1 (Glo1). An optimized inducer of Glo1 expression, trans-resveratrol and hesperetin combination, normalized increased MG concentration, corrected insulin resistance and decreased low grade inflammation in overweight and obese subjects. We propose that dicarbonyl stress, through increased formation of MG-glycated proteins, may be an important physiological stimulus of the UPR and Glo1 inducers may provide a route to effective suppression and therapy. With further investigation and validation, this may provide key new insight into physiological activators of the UPR and association with dicarbonyl stress.

Impact of insulin resistance on subclinical left ventricular dysfunction in normal weight and overweight/obese japanese subjects in a general community

BACKGROUND

Insulin resistance carries increased risk of heart failure, although the pathophysiological mechanisms remain unclear. LV global longitudinal strain (LVGLS) assessed by speckle-tracking echocardiography has emerged as an important tool to detect early LV systolic abnormalities. This study aimed to investigate the association between insulin resistance and subclinical left ventricular (LV) dysfunction in a sample of the general population without overt cardiac disease.

METHODS

We investigated 539 participants who voluntarily underwent extensive cardiovascular health check including laboratory test and speckle-tracking echocardiography. Glycemic profiles were categorized into 3 groups according to homeostatic model assessment of insulin resistance (HOMA-IR): absence of insulin resistance (HOMA-IR < 1.5), presence of insulin resistance (HOMA-IR ≥ 1.5) and diabetes mellitus (DM). Multivariable logistic regression models were conducted to evaluate the association between abnormal glucose metabolism and impaired LVGLS (> - 16.65%).

RESULTS

Forty-five (8.3%) participants had DM and 66 (12.2%) had abnormal HOMA-IR. LV mass index and E/e' ratio did not differ between participants with and without abnormal HOMA-IR, whereas abnormal HOMA-IR group had significantly decreased LVGLS (- 17.6 ± 2.6% vs. - 19.7 ± 3.1%, p < 0.05). The prevalence of impaired LVGLS was higher in abnormal HOMA-IR group compared with normal HOMA-IR group (42.4% vs. 14.0%) and similar to that of DM (48.9%). In multivariable analyses, glycemic abnormalities were significantly associated with impaired LVGLS, independent of traditional cardiovascular risk factors and pertinent laboratory and echocardiographic parameters [adjusted odds ratio (OR) 2.38, p = 0.007 for abnormal HOMA-IR; adjusted OR 3.02, p = 0.003 for DM]. The independent association persisted even after adjustment for waist circumference as a marker of abdominal adiposity. Sub-group analyses stratified by body mass index showed significant association between abnormal HOMA-IR and impaired LVGLS in normal weight individuals (adjusted OR 4.59, p = 0.001), but not in overweight/obese individuals (adjusted OR 1.62, p = 0.300).

CONCLUSIONS

In the general population without overt cardiac disease, insulin resistance carries independent risk for subclinical LV dysfunction, especially in normal weight individuals.

Pathophysiology-based subphenotyping of individuals at elevated risk for type 2 diabetes

The state of intermediate hyperglycemia is indicative of elevated risk of developing type 2 diabetes1. However, the current definition of prediabetes neither reflects subphenotypes of pathophysiology of type 2 diabetes nor is predictive of future metabolic trajectories. We used partitioning on variables derived from oral glucose tolerance tests, MRI-measured body fat distribution, liver fat content and genetic risk in a cohort of extensively phenotyped individuals who are at increased risk for type 2 diabetes2,3 to identify six distinct clusters of subphenotypes. Three of the identified subphenotypes have increased glycemia (clusters 3, 5 and 6), but only individuals in clusters 5 and 3 have imminent diabetes risks. By contrast, those in cluster 6 have moderate risk of type 2 diabetes, but an increased risk of kidney disease and all-cause mortality. Findings were replicated in an independent cohort using simple anthropomorphic and glycemic constructs4. This proof-of-concept study demonstrates that pathophysiological heterogeneity exists before diagnosis of type 2 diabetes and highlights a group of individuals who have an increased risk of complications without rapid progression to overt type 2 diabetes.