Limitation of the validity of the homeostasis model assessment as an index of insulin resistance in Korea

The triglyceride glucose (TyG) index is associated with decreased myocardial mechano-energetic efficiency in individuals with different glucose tolerance status

BACKGROUND

This investigation had two main objectives: (1) to compare the triglyceride-glucose (TyG) index with the homeostasis model assessment of insulin resistance (HOMA-IR) in relation to insulin-stimulated myocardial glucose metabolic rate (MrGlu), measured by a dynamic positron emission tomography (PET) scan using 18F-fluorodeoxyglucose (18F-FDG) coupled with a euglycemic-hyperinsulinemic clamp; and (2) to assess whether the TyG index correlates with myocardial mechano-energetic efficiency (MEE).

METHODS

We evaluated MrGlu in 46 participants who had no prior diagnosis of coronary heart disease. Myocardial MrGlu was quantified by 18F-FDG PET during a euglycemic-hyperinsulinemic clamp. In a larger cohort of 1820 individuals, myocardial MEE per gram of left ventricular mass (MEEi) was measured echocardiographically. The TyG index was computed as the Ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2].

RESULTS

When compared to HOMA-IR, the TyG index exhibited a stronger correlation with myocardial MrGlu (Pearson's r = -.566 for TyG vs. -.471 for HOMA-IR). Within the larger cohort, individuals in the highest TyG quartile showed significantly reduced MEEi compared to those in the lowest quartile (p < .001). Stepwise multivariate linear regression confirmed that the TyG index was the most significant determinant of MEEi, independent of traditional cardio-metabolic risk factors.

CONCLUSIONS

Our findings suggest that the TyG index is superior to HOMA-IR as an indicator of cardiac insulin resistance and that it independently correlates with MEEi. Thus, the TyG index may serve as a valuable, readily available tool to identify subjects at elevated cardiovascular risk.

Comparison of SPISE and METS-IR and Other Markers to Predict Insulin Resistance and Elevated Liver Transaminases in Children and Adolescents

BACKGRUOUND

Studies on predictive markers of insulin resistance (IR) and elevated liver transaminases in children and adolescents are limited. We evaluated the predictive capabilities of the single-point insulin sensitivity estimator (SPISE) index, metabolic score for insulin resistance (METS-IR), homeostasis model assessment of insulin resistance (HOMA-IR), the triglyceride (TG)/ high-density lipoprotein cholesterol (HDL-C) ratio, and the triglyceride-glucose index (TyG) for IR and alanine aminotransferase (ALT) elevation in this population.

METHODS

Data from 1,593 participants aged 10 to 18 years were analyzed using a nationwide survey. Logistic regression analysis was performed with IR and ALT elevation as dependent variables. Receiver operating characteristic (ROC) curves were generated to assess predictive capability. Proportions of IR and ALT elevation were compared after dividing participants based on parameter cutoff points.

RESULTS

All parameters were significantly associated with IR and ALT elevation, even after adjusting for age and sex, and predicted IR and ALT elevation in ROC curves (all P<0.001). The areas under the ROC curve of SPISE and METS-IR were higher than those of TyG and TG/HDL-C for predicting IR and were higher than those of HOMA-IR, TyG, and TG/HDL-C for predicting ALT elevation. The proportions of individuals with IR and ALT elevation were higher among those with METS-IR, TyG, and TG/ HDL-C values higher than the cutoff points, whereas they were lower among those with SPISE higher than the cutoff point.

CONCLUSION

SPISE and METS-IR are superior to TG/HDL-C and TyG in predicting IR and ALT elevation. Thus, this study identified valuable predictive markers for young individuals.

Insulin-related traits and prostate cancer: A Mendelian randomization study

Investigating the causal relationship between insulin secretion and prostate cancer (PCa) development is challenging due to the multifactorial nature of PCa, which complicates the isolation of the specific impact of insulin-related factors. We conducted a Mendelian randomization (MR) study to investigate the associations between insulin secretion-related traits and PCa. We used 36, 60, 56, 23, 48, and 49 single nucleotide polymorphisms (SNPs) as instrumental variables for fasting insulin, insulin sensitivity, proinsulin, and proinsulin in nondiabetic individuals, individuals with diabetes, and individuals receiving exogenous insulin, respectively. These SNPs were selected from various genome-wide association studies. To clarify the causal relationship between insulin-related traits and PCa, we utilized a multivariable MR analysis to adjust for obesity and body fat percentage. Additionally, two-step Mendelian randomization was conducted to assess the role of insulin-like growth factor 1 (IGF-1) in the relationship between proinsulin and PCa. Two-sample MR analysis revealed strong associations between genetically predicted fasting insulin, insulin sensitivity, proinsulin, and proinsulin in nondiabetic individuals and the development of PCa. After adjustment for obesity and body fat percentage using multivariable MR analysis, proinsulin remained significantly associated with PCa, whereas other factors were not. Furthermore, two-step MR analysis demonstrated that proinsulin acts as a negative factor in prostate carcinogenesis, largely independent of IGF-1. This study provides evidence suggesting that proinsulin may act as a negative factor contributing to the development of PCa. Novel therapies targeting proinsulin may have potential benefits for PCa patients, potentially reducing the need for unnecessary surgical treatments.

Impaired insulin sensitivity measured by estimated glucose disposal rate is associated with decreased myocardial mechano-energetic efficiency in non-diabetic individuals

BACKGROUND AND AIMS

Impaired myocardial mechano-energetic efficiency (MEE) has been associated with cardiac insulin resistance measured by dynamic positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) combined with euglycemic-hyperinsulinemic clamp. Estimate glucose disposal rate (eGDR) index has a good correlation with whole-body insulin sensitivity. It remains unsettled whether eGDR index is a suitable proxy of cardiac insulin sensitivity as well as its association with myocardial MEE. The aims of this study were: 1) to compare eGDR index with HOMA-IR, QUICKI and FIRI indexes for association with myocardial glucose metabolic rate (MrGlu); and 2) to determine the association of eGDR index with myocardial MEE.

METHODS

We evaluated MrGlu using PET with 18F-FDG combined with euglycemic-hyperinsulinemic clamp in 50 individuals without history of coronary heart disease. Myocardial MEE per gram of left ventricular mass (MEEi) was measured in 1181 subjects by echocardiography. eGDR (mg kg-1/min) was calculated as: 21.158 - (0.09 × waist circumference in cm) - (3.407 × hypertension, 1 = yes 0 = no) - (0.551 × HbA1c%).

RESULTS

eGDR index was more strongly associated with myocardial MrGlu than HOMA-IR, QUICKI, and FIRI indexes (r = -0.662, r = -0.492, r = 0.570, and r = -0.492, respectively). Individuals in the lower tertiles of eGDR exhibited a significant reduction of MEEi as compared to those in the highest tertile (P < 0.001). In a stepwise multivariate linear regression analysis eGDR index was the major determinant of MEEi independently of well-established cardio-metabolic risk factors.

CONCLUSIONS

These data suggest that the eGDR index may be a useful marker to identifying individuals at high cardiovascular risk.

Non-Insulin-Based Indices of Insulin Resistance for Predicting Incident Albuminuria: A Nationwide Population-Based Study

BACKGROUND

Studies have shown that incident albuminuria is associated with insulin resistance (IR); however, an IR marker that best predicts the prevalence of albuminuria has not yet been established. This study explored the association between IR and incident albuminuria using various IR indices, including the homeostasis model assessment of IR (HOMA-IR), metabolic score for IR (METS-IR), and triglyceride-glucose (TyG) index, and compared their predictive abilities for the prevalence of albuminuria.

METHODS

A total of 4,982 Korean adults from the 2019 Korea National Health and Nutritional Examination Survey were analyzed. The odds of albuminuria were determined using the quartiles of the IR indices. Receiver operating characteristic (ROC) curves were used to calculate the area under the ROC curve and predictability. The cutoff values for albuminuria detection were also computed.

RESULTS

An increase in the quartiles of all three IR indices was associated with incident albuminuria, even after full adjustment for covariates (HOMA-IR: odds ratio [OR], 1.906; 95% confidence interval [CI], 1.311-2.772; P=0.006; METS-IR: OR, 2.236; 95% CI, 1.353-3.694; P=0.002; TyG index: OR, 1.757; 95% CI, 1.213-2.544; P=0.003). The area under the ROC curve for incident albuminuria based on the HOMA-IR, METS-IR, and TyG indices was 0.594 (95% CI, 0.568-0.619), 0.633 (95% CI, 0.607-0.659), and 0.631 (95% CI, 0.606-0.656), respectively. The optimal cutoff values for predicting albuminuria were 2.38, 35.38, and 8.72 for the HOMA-IR, METS-IR, and TyG indices, respectively.

CONCLUSION

The METS-IR and TyG indices outperformed HOMA-IR in predicting incident albuminuria.

Hepatic and metabolic outcomes induced by sub-chronic exposure to polystyrene microplastics in mice

Microplastics (MPs) have attracted significant attention due to their global distribution in living environments. Although some studies have reported MP-induced hepatotoxicity in mouse models, a systematic approach to MP-mediated liver toxicity was still lacking. Therefore, we used a mouse model to study the sub-chronic effects of MP exposure on the liver. Female C57BL/6 mice, aged 6 weeks, received an oral administration of 0.3 mg of Nile Red-labeled polystyrene (PS) microplastics, with particle sizes of 0.5 µm (submicron) and 5 µm (micron), via gavage, while control mice received vehicle only. Each mouse was exposed to MPs twice a week for 12 weeks. After sacrifice, the levels of MP accumulation, oxidative stress, inflammation, and pathological changes were measured in the mouse liver, and blood samples were collected for serum biochemistry analysis. Our results demonstrated that 0.5 µm PS-MPs were accumulated in mouse livers post-MP exposure, but not in the 5 µm MP exposure group. Simultaneously, increased levels of glucose, triglyceride, alanine transaminase (ALT), aspartate transaminase (AST), superoxide dismutase, 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), interleukin-6, and lipid droplets were found in the 0.5 µm MP exposure group, while the fewer responses, including elevated liver weight index, glucose, high-density lipoprotein, AST, and decreased HNE-MA were observed in 5 µm MP exposure group. These results indicate that sub-chronic exposure to submicron MPs causes MP deposition in mouse livers, which further induces oxidative stress, increases inflammatory cytokines and perturbs glucose and lipid homeostasis, which might trigger more severe metabolic dysfunction or non-alcoholic steatohepatitis-like hepatotoxicity.

Prediction of insulin resistance and elevated liver transaminases using serum uric acid and derived markers in children and adolescents

OBJECTIVE

To investigate the relationship of serum uric acid (Uacid) and derived parameters as predictors of insulin resistance (IR) and elevated liver transaminases in children and adolescents METHODS: Data of 1648 participants aged 10-18 years was analyzed using nationwide survey. Logistic regression analysis was performed with IR and elevated liver transaminases as dependent variables, and odds ratios (ORs) and 95% confidence intervals (CIs) for tertiles 2 and 3 of each parameter in comparison to tertile 1, which served as the reference. Receiver operating characteristic (ROC) curves were generated to assess predictability of the parameters for IR and elevated liver transaminases.

RESULTS

Hyperuricemia, IR, and elevated liver transaminases were significantly associated with each other. All Uacid and derived markers showed continuous increase in ORs and 95% CIs for IR and elevated liver transaminases across the tertiles of several biochemical and metabolic variables of interest (all p < 0.001), and were also significantly predictive in ROC curve. Overall, Uacid combined with obesity indices showed higher ORs and area under the curve (AUC) compared to Uacid alone. Uacid-body mass index (BMI) standard deviation score presented the largest AUC for IR. For elevated liver transaminases, Uacid-BMI and Uacid-waist-to-height ratio showed the largest AUC.

CONCLUSIONS

Uacid combined with obesity indices are robust markers for prediction of IR and elevated liver transaminases in children and adolescents. Uacid and derived markers have potential as simple markers which do not require fasting for screening of IR and elevated liver transaminases in children and adolescents.

Relationship between the triglyceride-glucose index and depression in individuals with chronic kidney disease: A cross-sectional study from National Health and Nutrition Examination Survey 2005-2020

Accumulating evidence indicates that individuals with chronic kidney disease (CKD) are at an increased risk of experiencing depressive disorders, which may accelerate its progression. However, the relationship between the triglyceride-glucose (TyG) index and depression in CKD individuals remains unclear. Therefore, this cross-sectional study aimed to assess whether such a relationship exists. To this end, the CKD cohort of the National Health and Nutrition Examination Survey from 2005 to 2020 was analyzed using multivariable logistic regression analyses and a generalized additive approach. A recursive algorithm was employed to pinpoint the turning point, constructing a dual-segment linear regression model. The study included 10,563 participants. After controlling for all variables, the odds ratios and 95% confidence intervals indicated a 1.24 (range, 1.09-1.42) relationship between the TyG index and depression in the CKD cohort. The findings underscored an asymmetrical association, with a pivotal value at a TyG index 9.29. Above this threshold, the adjusted odds ratio (95% confidence interval) was 1.10 (range, 0.93-1.31). This relationship was significant among the obese subgroups. The study results highlight the complex relationship between the TyG index and depression among American adults with CKD.

Baseline and change in serum uric acid level over time and resolution of nonalcoholic fatty liver disease in young adults: The Kangbuk Samsung Health Study

AIMS

To determine the association between: (i) baseline serum uric acid (SUA) level and (ii) SUA changes over time, and nonalcoholic fatty liver disease (NAFLD) resolution.

MATERIALS AND METHODS

A retrospective cohort study, comprising 38 483 subjects aged <40 years with pre-existing NAFLD, was undertaken. The effects of SUA changes over time were studied in 25 266 subjects. Participants underwent a health examination between 2011 and 2019, and at least one follow-up liver ultrasonography scan up to December 2020. Exposures included baseline SUA level and SUA changes between baseline and subsequent visits, categorized into quintiles. The reference group was the third quintile (Q3) containing zero change. The primary endpoint was resolution of NAFLD.

RESULTS

During a median follow-up of 4 years, low baseline SUA level and decreases in SUA levels over time were independently associated with NAFLD resolution (p for trend <0.001). Using SUA as a continuous variable, the likelihood of NAFLD resolution was increased by 10% and 13% in men and women, respectively, per 1-mg/dL decrease in SUA. In a time-dependent model with changes in SUA treated as a time-varying covariate, adjusted hazard ratios (95% confidence intervals) for NAFLD resolution comparing Q1 (highest decrease) and Q2 (slight decrease) to Q3 (reference) were 1.63 (1.49-1.78) and 1.23 (1.11-1.35) in men and 1.78 (1.49-2.12) and 1.18 (0.95-1.46) in women, respectively.

CONCLUSIONS

Low baseline SUA levels and a decrease in SUA levels over time were both associated with NAFLD resolution in young adults.

Insulin Resistance Is Better Estimated by Using Fasting Glucose, Lipid Profile, and Body Fat Percent Than by HOMA-IR in Japanese Patients with Type 2 Diabetes and Impaired Glucose Tolerance: An Exploratory Study

Aims: The aim of the present study is to estimate insulin resistance (IR) using clinically available parameters except for serum insulin or C-peptide concentration to overcome the limitation of homeostasis model assessment of IR (HOMA-IR), which has been widely used in clinical practice. Patients and Methods: Fifty-two admitted patients with type 2 diabetes or impaired glucose tolerance were enrolled, and steady state plasma glucose (SSPG) method and cookie meal tolerance test were performed together with fasting blood sampling and anthropometric measurements. Insulin sensitivity measured by SSPG was estimated as glucose clearance corrected by the excretion of glucose into urine (C-GC). Results: Log-transformed (C-GC) was negatively correlated with fasting plasma glucose (FPG), log (Fasting triglyceride: TG), log (Fasting TG/Fasting high-density lipoprotein cholesterol: HDLC), and their area under the curves (AUCs). Fasting and AUC-HDLC was positively and fasting free fatty acid (FFA) was negatively correlated with log (C-GC). Body fat (%) was negatively correlated with log (C-GC). Multiple regression analysis on log (C-GC) as an outcome variable revealed that FPG, log (AUC-TG/AUC-HDLC), body fat (%), and fasting FFA were selected as significant predictive variables and contributed to log (C-GC) by 60% (adjusted R2). Replacing log (AUC-TG/AUC-HDLC) with its fasting value, log (Fasting TG/Fasting HDLC), this model still showed a strong contribution to log (C-GC) by 57% (adjusted R2). These contributions were stronger than those in log (HOMA-IR) (52.5%), log (Fasting C-peptide) (45.7%) to log (C-GC). Conclusions: It is plausible that our estimation for IR without the inclusion of plasma insulin concentration can be applied in Japanese patients whose HOMA-IR is not appropriately available. The model using fasting values is less complicated and could be the best way for the estimation of IR.

Triglyceride-glucose index and obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) has a bidirectional association with metabolic syndrome, and insulin resistance (IR). The triglyceride-glucose (TyG) index could be a simply calculated marker of IR in OSA. However, its clinical application appears still limited. Hence, this systematic review and meta-analysis aimed to respond to this question by analyzing all the existing studies showing an association between OSA and the TyG index.

METHODS

Four online databases, including PubMed, Scopus, the Web of Science, and Embase were searched for studies evaluating the TyG index in OSA. After screening and data extraction, a random-effect meta-analysis was performed to compare the TyG index in OSA patients vs. healthy controls by calculating standardized mean difference (SMD) and 95% confidence interval (CI) and pooling the area under the curves (AUCs) for diagnosis of OSA based on this index.

RESULTS

Ten studies involving 16,726 individuals were included in the current systematic review. Meta-analysis indicated that there was a significantly higher TyG index in patients with OSA, compared with the healthy controls (SMD 0.856, 95% CI 0.579 to 1.132, P < 0.001). Also, TyG had a diagnostic ability for OSA representing a pooled AUC of 0.681 (95% CI 0.627 to 0.735). However, based on the two studies' findings, no difference between different severities of OSA was observed. Finally, our data showed that the TyG index is a good potential predictor of adverse outcomes in these patients.

CONCLUSION

Our study revealed that the TyG index is an easy-to-measure marker of IR for assessing OSA, both in diagnosis and prognosis. Our study supports its implementation in routine practice to help clinicians in decision-making and patient stratification.

History of Gestational Diabetes and Incident Nonalcoholic Fatty Liver Disease: The Kangbuk Samsung Health Study

INTRODUCTION

We examined the relationship between a previous history of gestational diabetes mellitus (pGDM) and risk of incident nonalcoholic fatty liver disease (NAFLD) and investigated the effect of insulin resistance or development of diabetes as mediators of any association.

METHODS

We performed a retrospective cohort study of 64,397 Korean parous women without NAFLD. The presence of and the severity of NAFLD at baseline and follow-up were assessed using liver ultrasonography. Cox proportional hazards models were used to determine adjusted hazard ratios for incident NAFLD according to a self-reported GDM history, adjusting for confounders as time-dependent variables. Mediation analyses were performed to examine whether diabetes or insulin resistance may mediate the association between pGDM and incident NAFLD.

RESULTS

During a median follow-up of 3.7 years, 6,032 women developed incident NAFLD (of whom 343 had moderate-to-severe NAFLD). Multivariable adjusted hazard ratios (95% confidence intervals) comparing women with time-dependent pGDM with the reference group (no pGDM) were 1.46 (1.33-1.59) and 1.75 (1.25-2.44) for incident overall NAFLD and moderate-to-severe NAFLD, respectively. These associations remained significant in analyses restricted to women with normal fasting glucose <100 mg/dL or that excluded women with prevalent diabetes at baseline or incident diabetes during follow-up. Diabetes and insulin resistance (Homeostatic Model Assessment for Insulin Resistance) each mediated <10% of the association between pGDM and overall NAFLD development.

DISCUSSION

A previous history of GDM is an independent risk factor for NAFLD development. Insulin resistance, measured by the Homeostatic Model Assessment for Insulin Resistance, and development of diabetes each explained only <10% of the association between GDM and incident NAFLD.

Triglyceride-glucose index and heart failure: a systematic review and meta-analysis

BACKGROUND

Insulin resistance (IR) is a major metabolic disorder observed in heart failure (HF) and is tightly associated with patients' poor prognosis. The triglyceride-glucose index (TyG) has been proposed as a surrogate marker of IR in HF. Yet, whether TyG is a reliable clinical marker is still under debate. Hence, we aimed to respond to this relevant question via a systematic review and meta-analysis of existing studies.

METHODS

A systematic search was conducted in PubMed, Embase, Scopus, and Web of Science to find studies investigating the TyG index in patients with HF or its association with the incidence of HF. Adjusted hazard ratios (HR) and 95% confidence intervals (CI) were pooled through random-effect meta-analysis. HRs were calculated using TyG as a continuous variable (1 unit increase) and by comparing the group with the highest TyG to the lowest TyG group.

RESULTS

Thirty studies, involving 772,809 participants, were included in this systematic review. Meta-analysis of seven studies comparing the highest-TyG to the lowest-TyG group showed a significantly increased risk of HF in the former group (HR 1.21, 95% CI 1.14 to 1.29, P < 0.01). The same result was found when pooling the HRs for a one-unit increase in the TyG index (HR 1.17, 95% CI 1.08 to 1.26). Similarly, a more elevated TyG index was associated with a higher incidence of HF in patients with type 2 diabetes or coronary artery disease. Additionally, the incidence of adverse events (readmission and mortality) in patients with HF was associated with TyG.

CONCLUSION

Our findings support the TyG index as a valuable marker to assess the risk of HF incidence in different populations and as a prognostic marker in patients with HF. Further studies should be conducted to confirm these associations and investigate the clinical utility of the TyG index.

Association of plasminogen activator inhibitor-1 and fibroblastic growth factor 21 in 3 groups of type 2 diabetes: Without overweight/obesity, free of insulin resistance, and without hepatosteatosis

The physiological effects of fibroblast growth factor 21 (FGF21), leading to beneficial metabolic outcomes, have been extensively revealed in recent decades. Significantly elevated serum levels of FGF21 in obesity and type 2 diabetes mellitus (T2DM) are referred to as FGF21 resistance. However, Asian population tend to develop metabolic disorders at a lesser degree of obesity than those of Western. This study aimed to explore factors potentially related to serum FGF21 according to the severity of metabolic disorders in patients with T2DM. This cross-sectional study included 176 T2DM patients. The patients were categorized according to whether they had hepatic steatosis (fatty liver index [FLI] ≥ 60), insulin resistance (homeostasis model assessment of insulin resistance [HOMA-R] ≥ median), and/or overweight/obesity (body mass index [BMI] ≥ 25.0 kg/m2). Independent predictors of serum FGF21 were determined using multiple linear regression analysis in these 3 groups of T2DM patients. Circulating FGF21 levels were correlated positively with BMI, abdominal fat areas, leptin, and plasminogen activator inhibitor-1 (PAI-1). After adjustment for potential confounders, multiple linear regression analysis identified leptin as a factor strongly associated with serum FGF21 levels in all patients. Moreover, PAI-1 was a significant predictor of FGF21 in those with FLI < 60, BMI < 25.0 kg/m2, and HOMA-R < median, while leptin was the only independent factor in each of their counterparts. The factors related to serum FGF21 differ according to the severity of metabolic disorders. FGF21 appears to be independently associated with PAI-1 in T2DM patients: without overweight/obesity, those free of insulin resistance, and those without hepatic steatosis.

Triglyceride-Glucose Index Predicts Future Atherosclerotic Cardiovascular Diseases: A 16-Year Follow-up in a Prospective, Community-Dwelling Cohort Study

BACKGRUOUND

While the triglyceride-glucose (TyG) index is a measure of insulin resistance, its association with cardiovascular disease (CVD) has not been well elucidated. We evaluated the TyG index for prediction of CVDs in a prospective large communitybased cohort.

METHODS

Individuals 40 to 70 years old were prospectively followed for a median 15.6 years. The TyG index was calculated as the Ln [fasting triglycerides (mg/dL)×fasting glucose (mg/dL)/2]. CVDs included any acute myocardial infarction, coronary artery disease or cerebrovascular disease. We used a Cox proportional hazards model to estimate CVD risks according to quartiles of the TyG index and plotted the receiver operating characteristics curve for the incident CVD.

RESULTS

Among 8,511 subjects (age 51.9±8.8 years; 47.5% males), 931 (10.9%) had incident CVDs during the follow-up. After adjustment for age, sex, body mass index, diabetes mellitus, hypertension, total cholesterol, smoking, alcohol, exercise, and C-reactive protein, subjects in the highest TyG quartile had 36% increased risk of incident CVD compared with the lowest TyG quartile (hazard ratio, 1.36; 95% confidence interval, 1.10 to 1.68). Carotid plaque, assessed by ultrasonography was more frequent in subjects in the higher quartile of TyG index (P for trend=0.049 in men and P for trend <0.001 in women). The TyG index had a higher predictive power for CVDs than the homeostasis model assessment of insulin resistance (HOMA-IR) (area under the curve, 0.578 for TyG and 0.543 for HOMA-IR). Adding TyG index on diabetes or hypertension alone gave sounder predictability for CVDs.

CONCLUSION

The TyG index is independently associated with future CVDs in 16 years of follow-up in large, prospective Korean cohort.

Hand grip strength is inversely associated with total daily insulin dose requirement in patients with type 2 diabetes mellitus: a cross-sectional study

Background

Short-term (2 weeks to 3 months) insulin intensive therapy using continuous subcutaneous insulin infusion (CSII) can improve islet beta cell function and prolong glycemic remission in patients with newly diagnosed type 2 diabetes mellitus (T2DM). However, the total daily insulin dose (TDD, IU/kg/d) required to achieve near-normoglycemic control with CSII still needs to be frequently adjusted based on blood glucose monitoring. Although real-time continuous glucose monitoring (rtCGM), which measures the interstitial fluid glucose concentration continuously without much difficulty, facilitates the adjustment of insulin dosage, its adoption in the T2DM population is strictly limited by insurance coverage and lack of awareness of rtCGM among clinicians. Thus, it is of clinical significance to identify easy-to-use parameters that may allow a more rapid and accurate prediction of TDD requirement. This study aimed to explore the association between hand grip strength (HGS) and TDD requirement in patients with T2DM receiving CSII therapy.

Methods

A total of 180 eligible patients with T2DM were enrolled in the study and divided into three groups based on their HGS: low (L), medium (M), and high (H). The TDD requirement was calculated on day 7 or 8 of CSII treatment. Anthropometric parameters, including HGS, skeletal muscle mass, skeletal muscle index (SMI) and 6-m gait speed, and laboratory data, were collected on the morning of the second day after admission, within the first 24 h of CSII therapy. These parameters were used to identify significant predictors of TDD requirement using Pearson or Spearman correlation test, and stepwise multiple regression analysis.

Results

There were no significant differences in age, duration of T2DM, waist-to-hip ratio (WHR), body mass index (BMI), blood pressure, liver function, estimated glomerular filtration rate, triglyceride, total cholesterol, glycosylated hemoglobin A1c (HbA1c), homeostatic model assessment of insulin resistance (HOMA-IR), and homeostasis model assessment of beta cell function (HOMA-β) among the groups. The H group had higher body muscle mass-to-fat ratio (BMFR), skeletal muscle mass-to-fat ratio (SMFR), SMI, 6-m gait speed, and lower TDD requirement than the M and L groups. The HGS negatively correlated with TDD requirement (r = -0.33, p < 0.001) after adjusting for sex, age, BMI, WHR, HbA1c, Ln (HOMA-β), Ln (HOMA-IR), Ln (BMFR), Ln (SMFR), SMI, and 6-m gait speed. Multivariate stepwise regression analysis indicated that HGS was an independent predictor of TDD requirement in patients with T2DM (β = -0.45, p < 0 001).

Conclusion

Lower HGS is associated with an increased TDD requirement in T2DM patients. HGS may facilitate the prediction of TDD requirement in T2DM patients receiving CSII therapy.

β-hydroxybutyrate as a biomarker of β-cell function in new-onset type 2 diabetes and its association with treatment response at 6 months

AIMS

Increasing attention has been paid to the potential metabolic benefits of ketone bodies, but the clinical relevance of ketone bodies in newly diagnosed type 2 diabetes mellitus (T2D) remains unclear. We investigated the clinical implications of ketone bodies at the time of diagnosis in patients with drug-naïve T2D.

METHODS

Clinical data including serum β-hydroxybutyrate (βHB) levels, were collected from 369 patients with newly diagnosed drug-naïve T2D from 2017 to 2021. Subjects were categorized into four βHB groups based on the level of initial serum βHB. The associations of initial serum βHB and urinary ketone levels with glucometabolic indices were analyzed.

RESULTS

Higher serum βHB group was associated with higher levels of glycemic parameters including glycated hemoglobin (HbA1c) with lower levels of indices for insulin secretory function at the point of initial diagnosis of T2D. Nevertheless, higher serum βHB group was an independent determinant of a greater relative improvement in HbA1c after 6 months of anti-diabetic treatment, regardless of the type of anti-diabetic drug. In addition, patients in higher serum βHB group were more likely to have well-controlled HbA1c levels (≤6.5%) after 6 months of anti-diabetic treatment.

CONCLUSION

In patients with newly diagnosed T2D, a higher initial βHB level was a significant predictive marker of greater glycemic improvement after antidiabetic treatment, despite its associations with hyperglycemia and decreased insulin secretion at baseline.

Discriminant Model for Insulin Resistance in Type 2 Diabetic Patients

Introduction: Patients with type 2 diabetes mellitus tend to have insulin resistance, a condition that is evaluated using expensive methods that are not easily accessible in routine clinical practice. Objective: To determine the anthropometric, clinical, and metabolic parameters that allow for the discrimination of type 2 diabetic patients who have insulin resistance from those who do not. Methods: A cross-sectional analytical observational study was carried out in 92 type 2 diabetic patients. A discriminant analysis was applied using the SPSS statistical package to establish the characteristics that differentiate type 2 diabetic patients with insulin resistance from those without it. Results: Most of the variables analyzed in this study have a statistically significant association with the HOMA-IR. However, only HDL-c, LDL-c, glycemia, BMI, and tobacco exposure time allow for the discrimination of type 2 diabetic patients who have insulin resistance from those who do not, considering the interaction between them. According to the absolute value of the structure matrix, the variable that contributes most to the discriminant model is HDL-c (-0.69). Conclusions: The association between HDL-c, LDL-c, glycemia, BMI, and tobacco exposure time allows for the discrimination of type 2 diabetic patients who have insulin resistance from those who do not. This constitutes a simple model that can be used in routine clinical practice.

Relationships Between Urinary Metals and Diabetes Traits Among Mexican Americans in Starr County, Texas, USA

Hispanics/Latinos have higher rates of type 2 diabetes (T2D), and the origins of these disparities are poorly understood. Environmental endocrine-disrupting chemicals (EDCs), including some metals and metalloids, are implicated as diabetes risk factors. Data indicate that Hispanics/Latinos may be disproportionately exposed to EDCs, yet they remain understudied with respect to environmental exposures and diabetes. The objective of this study is to determine how metal exposures contribute to T2D progression by evaluating the associations between 8 urinary metals and measures of glycemic status in 414 normoglycemic or prediabetic adults living in Starr County, Texas, a Hispanic/Latino community with high rates of diabetes and diabetes-associated mortality. We used multivariable linear regression to quantify the differences in homeostatic model assessments for pancreatic β-cell function, insulin resistance, and insulin sensitivity (HOMA-β, HOMA-IR, HOMA-S, respectively), plasma insulin, plasma glucose, and hemoglobin A1c (HbA1c) associated with increasing urinary metal concentrations. Quantile-based g-computation was utilized to assess mixture effects. After multivariable adjustment, urinary arsenic and molybdenum were associated with lower HOMA-β, HOMA-IR, and plasma insulin levels and higher HOMA-S. Additionally, higher urinary copper levels were associated with a reduced HOMA-β. Lastly, a higher concentration of the 8 metal mixtures was associated with lower HOMA-β, HOMA-IR, and plasma insulin levels as well as higher HOMA-S. Our data indicate that arsenic, molybdenum, copper, and this metal mixture are associated with alterations in measures of glucose homeostasis among non-diabetics in Starr County. This study is one of the first to comprehensively evaluate associations of urinary metals with glycemic measures in a high-risk Mexican American population.

TyG Index Performs Better Than HOMA-IR in Chinese Type 2 Diabetes Mellitus with a BMI < 35 kg/m2: A Hyperglycemic Clamp Validated Study

Background and objectives: Chinese type 2 diabetes mellitus (T2DM) patients are characterized by a low body mass index (BMI), and significant insulin resistance (IR). The triglyceride glucose (TyG) index has not been studied as a means of assessing IR in Chinese T2DM patients with a BMI < 35 kg/m2. Materials and Methods: An open-label cross-sectional study recruited 102 Chinese T2DM patients with a BMI < 35 kg/m2. The hyper-insulinemic euglycemic clamp, homeostatic model assessment of IR (HOMA-IR), and TyG index were used to determine the level of IR. Based on Pearson’s correlations, glucose disposal rate (GDR), TyG index, and HOMA-IR were analyzed. HOMA-IR and TyG index for IR were evaluated using multiple linear regression and multivariate logistic regression analyses. On the basis of the receiver operating characteristic (ROC) curve, the sensitivity, specificity, and optimal cut-off value of HOMA-IR and the TyG index were determined. Results: The mean values of GDR, HOMA-IR, and TyG index were 4.25 ± 1.81, 8.05 ± 7.98, and 8.12 ± 0.86 mg/kg/min, respectively. Pearson’s correlation coefficient was −0.418 between GDR and TyG index and −0.324 between GDR and HOMA-IR. ROC curve analysis showed that, among both sexes, the TyG index was a better discriminator of IR than HOMA-IR. The area under the ROC curve (AUC) of the TyG index (0.785, 0.691−0.879) was higher than that of HOMA-IR (0.73, 0.588−0.873) in all genders. The optimal cut-off values of the TyG index and HOMA-IR were 7.99 and 3.39, respectively. Conclusions: The TyG index showed more effectiveness in identifying IR in Chinese T2DM patients with a BMI < 35 kg/m2 compared to HOMA-IR.

Relationship between Habitual Intake of Vitamins and New-Onset Prediabetes/Diabetes after Acute Pancreatitis

Vitamins have many established roles in human health. However, the role of habitual dietary intake of vitamins in glucose homeostasis in individuals after acute pancreatitis (AP) is yet to be elucidated. The aim was to investigate the associations between habitual intake of fat- and water-soluble vitamins/vitamers and markers of glucose metabolism (fasting plasma glucose (FPG), homeostasis model assessment insulin resistance (HOMA-IR) index, and homeostasis model assessment β-cell function (HOMA-β)) in individuals after AP. A total of 106 participants after AP were included in this cross-sectional study and were grouped based on glycaemic status: new-onset prediabetes/diabetes after AP (NODAP), pre-existing prediabetes/type 2 diabetes (T2DM), and normoglycaemia after AP (NAP). Habitual intake of seven fat-soluble vitamins/vitamers and seven water-soluble vitamins were determined by the EPIC-Norfolk food frequency questionnaire. Multiple linear regression analyses were conducted using five statistical models built to adjust for covariates (age, sex, daily energy intake, visceral/subcutaneous fat volume ratio, smoking status, daily alcohol intake, aetiology of AP, number of AP episodes, cholecystectomy, and use of antidiabetic medications). In the NODAP group, three fat-soluble vitamins/vitamers (α-carotene, β-carotene, and total carotene) were significantly associated with HOMA-β. One water-soluble vitamin (vitamin B3) was also significantly associated with HOMA-β in the NODAP group. None of the studied vitamins were significantly associated with FPG or HOMA-IR in the NODAP group. Prospective longitudinal studies and randomised controlled trials are now warranted to investigate if the observed associations between vitamin/vitamer intake and NODAP are causal and to unveil the specific mechanisms underlying their involvement with NODAP.

Effect of Parathyroidectomy on Metabolic Homeostasis in Primary Hyperparathyroidism

Background: The benefits of parathyroidectomy on cardiovascular risk in primary hyperparathyroidism (PHPT) are controversial. This monocentric, observational, prospective study aimed to assess the effects of parathyroidectomy on glucose and lipid metabolism in classic or mild PHPT. Methods: Patients who underwent parathyroidectomy for classic (calcemia >2.85 mmol/L) or mild PHPT (calcemia ≤2.85 mmol/L) between 2016 and 2019 were included. A metabolic assessment was performed before and 1 year after parathyroidectomy. Patients with a history of diabetes were excluded. Results: Nineteen patients had classic and 120 had mild PHPT. Ninety-five percent were normocalcemic 6 months after surgery. Fasting plasma glucose and insulin levels decreased after parathyroidectomy in patients with mild PHPT (p < 0.001). HOMA-IR decreased after surgery in the overall population (p < 0.001), while plasma adiponectin concentrations increased in patients with both classic (p = 0.005) and mild PHPT (p < 0.001). Plasma triglyceride levels decreased significantly only in patients with classic PHPT (p = 0.021). Plasma PCSK9 levels decreased in patients with mild PHPT (p < 0.001). Conclusions: Parathyroidectomy for PHPT improves insulin resistance and decreases plasma triglyceride levels in classic PHPT and plasma PCSK9 levels in mild PHPT. Further studies are needed to better characterize the consequences of such metabolic risk factors’ improvements on cardiovascular events.

Sodium/glucose cotransporter 2 (SGLT2) inhibitors improve cardiac function by reducing JunD expression in human diabetic hearts

BACKGROUND

The pathogenesis of experimental diabetic cardiomyopathy may involve the activator protein 1 (AP-1) member, JunD. Using non-diabetic heart transplant (HTX) in recipients with diabetes, we examined the effects of the diabetic milieu (hyperglycemia and insulin resistance) on cardiac JunD expression over 12 months. Because sodium/glucose cotransporter-2 inhibitors (SGLT2i) significantly reverse high glucose-induced AP-1 binding in the proximal tubular cell, we investigated JunD expression in a subgroup of type 2 diabetic recipients receiving SGLT2i treatment.

METHODS

We evaluated 77 first HTX recipients (40 and 37 patients with and without diabetes, respectively). Among the recipients with diabetes, 17 (45.9%) were receiving SGLT2i treatment. HTX recipients underwent standard clinical evaluation (metabolic status, echocardiography, coronary computed tomography angiography, and endomyocardial biopsy). In the biopsy samples, we evaluated JunD, insulin receptor substrates 1 and 2 (IRS1 and IRS2), peroxisome proliferator-activated receptor-γ (PPAR-γ), and ceramide levels using real-time polymerase chain reaction and immunofluorescence. The biopsy evaluations in this study were performed at 1-4 weeks (basal), 5-12 weeks (intermediate), and up to 48 weeks (final, end of 12-month follow-up) after HTX.

RESULTS

There was a significant early and progressive increase in the cardiac expression of JunD/PPAR-γ and ceramide levels, along with a significant decrease in IRS1 and IRS2 in recipients with diabetes but not in those without diabetes. These molecular changes were blunted in patients with diabetes receiving SGLT2i treatment.

CONCLUSION

Early pathogenesis in human diabetic cardiomyopathy is associated with JunD/PPAR-γ overexpression and lipid accumulation following HTX in recipients with diabetes. Remarkably, this phenomenon was reduced by concomitant therapy with SGLT2i, which acted directly on diabetic hearts.

Dyslipidemia and associated cardiovascular risk factors in HIV-positive and HIV-negative patients visiting ambulatory clinics: A hospital-based study

Background

Dyslipidemia is a well-known risk factor for cardiovascular disease (CVD), accounting for more than half of all instances of coronary artery disease globally (CAD).

Purpose

The purpose of this study was to determine lipid-related cardiovascular risks in HIV-positive and HIV-negative individuals by evaluating lipid profiles, ratios, and other related parameters.

Methods

A hospital-based study was carried out from January 2019 to February 2021 in both HIV + and HIV- ambulatory patients.

Results

High TG (p = .003), high TC (p = .025), and low HDL (p < .001) were all associated with a two-fold increased risk of CVD in people aged 45 and up. Due to higher TG (p < .001) and lower HDL (p < .001), males were found to have a higher risk of atherogenic dyslipidemia. A twofold increase in the likelihood of higher TG levels has been associated with smoking (p = .032) and alcohol intake (p = .022). A twofold increase in a high TC/HDL ratio and an elevated TG/HDL ratio was observed with an increase in waist-to-height ratio (p = .030) and a high level of FBS (126 mg/dl) and/or validated diabetes (p = .017), respectively. In HIV + participants, central obesity (p < .001), diabetes (p < .001), and high blood pressure (p < .001) were all less common than in HIV- participants.

Conclusions

Dyslipidemia is linked to advanced age, male gender, diabetes, smoking, alcohol consumption, and increased waist circumference, all of which could lead to an increased risk of CVD, according to the study. The study also revealed that the risks are less common in HIV + people than in HIV-negative ambulatory patients.

Relation of cardiac function to insulin resistance as evaluated by hyperinsulinemic-euglycemic clamp analysis in individuals with type 2 diabetes

AIMS

Whereas homeostasis model assessment of insulin resistance (HOMA-IR), an easily measured but limited index of insulin resistance, has been shown to correlate with impairment of cardiac function in individuals without diabetes, the pathological relevance of insulin resistance to the development of cardiac dysfunction in individuals with type 2 diabetes has remained unclear. Here we investigated the relation between left ventricular (LV) function as assessed by echocardiography and insulin resistance as evaluated by hyperinsulinemic-euglycemic clamp analysis, the gold standard for measurement of this parameter, in individuals with type 2 diabetes.

METHODS

This retrospective study included 34 individuals with type 2 diabetes who underwent both hyperinsulinemic-euglycemic clamp analysis and echocardiography. Both the insulin sensitivity index (ISI) as determined by glucose clamp analysis as well as HOMA-IR were determined as measures of insulin resistance. The ratio of the peak early- to late-diastolic mitral inflow velocities (E/A) and the LV ejection fraction (LVEF) were determined as measures of diastolic and systolic function, respectively.

RESULTS

The ISI was significantly correlated with both the E/A ratio and LVEF (correlation coefficients of 0.480 and 0.360, respectively), whereas HOMA-IR was not correlated with either cardiac parameter. Multivariate analysis revealed that ISI was an independent predictor for both a high log [E/A] (P = 0.031) and a high LVEF (P = 0.045).

CONCLUSIONS

Insulin resistance as evaluated by hyperinsulinemic-euglycemic clamp analysis may be causally related to LV diastolic and systolic dysfunction in individuals with type 2 diabetes.

Insulin resistance and muscle weakness are synergistic risk factors for silent lacunar infarcts: the Bunkyo Health Study

Insulin resistance and muscle weakness are risk factors for silent lacunar infarcts (SLI), but it is unclear whether they are still independent risk factors when adjusted for each other. In addition, the effect of their combination on SLI is completely unknown. We evaluated SLI, insulin sensitivity, and knee extensor muscle strength by magnetic resonance imaging, PREDIM, and dynamometer, respectively, in 1531 elderly people aged 65–84 years living in an urban area of Tokyo. Among the study subjects, 251 (16.4%) had SLI. Impaired insulin sensitivity (High; 1.00 [reference], Medium; 1.53 [95% confidence interval (CI) 0.94–2.48], Low; 1.86 [1.02–3.39], p for trend 0.047) and reduced muscle strength (High; 1.00 [reference], Medium; 1.40 [0.98–2.02], Low; 1.49 [1.04–2.15], p for trend 0.037) were independently associated with increased risk for SLI in the fully adjusted model. In terms of combined, subjects classified as having the lowest insulin sensitivity and lowest strength were 4.33 times (95% CI 1.64–11.45) more likely to have a SLI than those classified as having the highest insulin sensitivity and highest strength. Impaired insulin sensitivity and reduced muscle strength were independently associated with higher risk of SLI in elderly subjects, and their combination synergistically increased this risk.

Beneficial effects of posttransplant dipeptidyl peptidase-4 inhibitor administration after pancreas transplantation to improve β cell function

Purpose

Dipeptidyl peptidase-4 (DPP-4) inhibitors lower blood glucose levels and enhance the function of pancreatic β cells. Yet, it is unknown whether posttransplant administration of DPP4 inhibitors is beneficial for pancreas transplant recipients.

Methods

We thus retrospectively analyzed the records of 312 patients who underwent pancreas transplantation between 2000 and 2018 at Asan Medical Center (Seoul, Korea) and compared the metabolic and survival outcomes according to DPP-4 inhibitor treatment.

Results

The patients were divided into the no DPP-4 inhibitor group (n = 165; no treatment with DPP-4 inhibitors or treated for <1 month) and the DPP-4 inhibitor group (n = 147; treated with DPP-4 inhibitors for ≥1 month). There were no significant differences in levels of glucose, hemoglobin A1c, and insulin between the 2 groups during 36 months of follow-up. However, the level of C-peptide was significantly higher in the DPP-4 inhibitor group at 1, 6, and 24 months posttransplant (all P < 0.05). Moreover, the DPP-4 inhibitor group had significantly higher rates of overall (log-rank test, P = 0.009) and death-censored (log-rank test, P = 0.036) graft survival during a 15-year follow-up.

Conclusion

Posttransplant DPP-4 inhibitor administration may help improve the clinical outcomes including β cell function after pancreas transplantation.

Lack of Improvement in Insulin Sensitivity After Pancreas Transplantation in Recipients With a High Level of Calcineurin Inhibitors

OBJECTIVES

This study aimed to assess posttransplant changes in insulin sensitivity and β-cell function of pancreas transplant recipients according to the type of diabetes mellitus (DM) and the pretransplant insulin sensitivity measured by the Matsuda Index (MI).

METHODS

We analyzed 60 patients who underwent pancreas transplantation and oral glucose tolerance test pretransplant and at 1 month posttransplant.

RESULTS

At 1 month posttransplant, insulin sensitivity did not show significant improvement; particularly, the MI was significantly lower after transplant in recipients with type 1 DM (T1DM) and those with pretransplant MI of 5 or greater. β-cell function was significantly improved after transplant in all recipients regardless of the type of DM and pretransplant MI values. Glucose control was significantly improved in recipients with T1DM and in all recipients regardless of the pretransplant MI values. Additional oral glucose tolerance test at 1 year posttransplant revealed that insulin sensitivity remained unimproved and β-cell function was higher compared with pretransplant. Glucose control had partially reverted to pretransplant levels in recipients with T1DM and those with pretransplant MI of 5 or greater.

CONCLUSIONS

Unlike β-cell function and glucose control, insulin sensitivity did not significantly improve until posttransplant 1 year after pancreas transplantation regardless of the type of DM or the degree of pretransplant insulin sensitivity.

Sex differences in sarcopenia and frailty among community-dwelling Korean older adults with diabetes: The Korean Frailty and Aging Cohort Study

AIMS/INTRODUCTION

We aimed to examine the prevalence of sarcopenia and frailty in Korean older adults with diabetes compared with individuals without diabetes.

MATERIALS AND METHODS

We analyzed the data of 2,403 participants aged 70-84 years enrolled in the Korean Frailty and Aging Cohort Study. Sarcopenia was defined using the Asian Working Group for Sarcopenia and the Foundation for the National Institutes of Health. Frailty was assessed by the Cardiovascular Health Study frailty phenotype criteria.

RESULTS

The mean age of the participants was 76.0 ± 3.9 years, and 47.2% were men. The prevalence of diabetes was 30.2% in men and 25.8% in women. Adults with diabetes showed a lower muscle mass index (appendicular skeletal muscle mass/body mass index) and handgrip strength in both sexes, but only the women showed decreased physical performance. Women with diabetes presented a higher prevalence of sarcopenia diagnosed by the Foundation for the National Institutes of Health criteria, and frailty compared with participants without diabetes (sarcopenia 14.7% vs 8.5%, P = 0.001; frailty 9.5% vs 4.9%, P = 0.003). Men in the high and middle tertiles for homeostatic model assessment of insulin resistance presented a significantly higher prevalence of sarcopenia, compared with men in the low tertile homeostatic model assessment of insulin resistance (high tertile 16.6%, middle tertile 13.3%, low tertile 8.6%).

CONCLUSIONS

In older adults with diabetes, muscle mass index and muscle strength were lower than in those without diabetes. However, the prevalence of sarcopenia and frailty was higher and physical performance was lower only in women with diabetes.

Association of the triglyceride and glucose index with low muscle mass: KNHANES 2008-2011

The triglyceride-glucose (TyG) index is a simple surrogate marker of insulin resistance. We evaluated the association of the TyG index with low muscle mass using a nationwide population-based representative data. This is a cross-sectional study that included 9477 participants aged ≥ 40 years from the Korea National Health and Nutrition Examination Survey between 2008 and 2011. The TyG index was calculated as ln[triglyceride (mg/dL) × fasting plasma glucose (mg/dL)/2]. Dual-energy X-ray absorptiometry was used to measure appendicular lean mass (ALM). Low muscle mass was defined an ALM/weight of 2 standard deviations (SD) below of young participants. The overall prevalence of low muscle mass was 4.7%. The prevalence of low muscle mass increased linearly with the quartiles of the TyG index, 2.5%, 4.2%, 5.6%, and 6.7% in Q1–Q4, respectively. The TyG index was negatively associated with ALM/weight both in men (r = − 0.302) and women (r = − 0.230). The odds ratio (OR) for low muscle mass was 2.08 in the highest quartile compared to the lowest quartile. High TyG index was associated with an increased risk of low muscle mass (OR for 1SD increase: 1.13). Increased TyG index was associated with the risk of low muscle mass independent of confounding factors.

Lifestyle modifications result in alterations in the gut microbiota in obese children

Background

The association between the gut microbiota and pediatric obesity was analyzed in a cross-sectional study. A prospective study of obese children was conducted to assess the gut microbial alterations after a weight change. We collected fecal samples from obese children before and after a 2-month weight reduction program that consisted of individual counseling for nutritional education and physical activity, and we performed 16S rRNA gene amplicon sequencing using an Illumina MiSeq platform.

Results

Thirty-six participants, aged 7 to 18 years, were classified into the fat loss (n = 17) and the fat gain (n = 19) groups according to the change in total body fat (%) after the intervention. The baseline analysis of the gut microbiota in the preintervention stages showed dysbiotic features of both groups compared with those of normal-weight children. In the fat loss group, significantly decreased proportions of Bacteroidetes phylum, Bacteroidia class, Bacteroidales order, Bacteroidaceae family, and Bacteroides genus, along with increased proportions of Firmicutes phylum, Clostridia class, and Clostridiales order, were observed after intervention. The microbial richness was significantly reduced, without a change in beta diversity in the fat loss group. The fat gain group showed significantly deceased proportions of Firmicutes phylum, Clostridia class, Clostridiales order, Lachnospiraceae family, and Eubacterium hallii group genus, without a change in diversity after the intervention. According to the functional metabolic analysis by the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2, the “Nitrate Reduction VI” and “Aspartate Superpathway” pathways were predicted to increase significantly in the fat loss group. The cooccurring networks of genera were constructed and showed the different microbes that drove the changes between the pre- and postintervention stages in the fat loss and fat gain groups.

Conclusions

This study demonstrated that lifestyle modifications can impact the composition, richness, and predicted functional profiles of the gut microbiota in obese children after weight changes.

Trial registration

ClinicalTrials.govNCT03812497, registration date January 23, 2019, retrospectively registered.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12866-020-02002-3.

Distinctive Metabolomics Patterns Associated With Insulin Resistance and Type 2 Diabetes Mellitus

Obesity is associated with an increased risk of insulin resistance (IR) and type 2 diabetes mellitus (T2DM) which is a multi-factorial disease associated with a dysregulated metabolism and can be prevented in pre-diabetic individuals with impaired glucose tolerance. A metabolomic approach emphasizing metabolic pathways is critical to our understanding of this heterogeneous disease. This study aimed to characterize the serum metabolomic fingerprint and multi-metabolite signatures associated with IR and T2DM. Here, we have used untargeted high-performance chemical isotope labeling (CIL) liquid chromatography-mass spectrometry (LC-MS) to identify candidate biomarkers of IR and T2DM in sera from 30 adults of normal weight, 26 obese adults, and 16 adults newly diagnosed with T2DM. Among the 3633 peak pairs detected, 62% were either identified or matched. A group of 78 metabolites were up-regulated and 111 metabolites were down-regulated comparing obese to lean group while 459 metabolites were up-regulated and 166 metabolites were down-regulated comparing T2DM to obese groups. Several metabolites were identified as IR potential biomarkers, including amino acids (Asn, Gln, and His), methionine (Met) sulfoxide, 2-methyl-3-hydroxy-5-formylpyridine-4-carboxylate, serotonin, L-2-amino-3-oxobutanoic acid, and 4,6-dihydroxyquinoline. T2DM was associated with dysregulation of 42 metabolites, including amino acids, amino acids metabolites, and dipeptides. In conclusion, these pilot data have identified IR and T2DM metabolomics panels as potential novel biomarkers of IR and identified metabolites associated with T2DM, with possible diagnostic and therapeutic applications. Further studies to confirm these associations in prospective cohorts are warranted.

Lipid Accumulation in Hearts Transplanted From Nondiabetic Donors to Diabetic Recipients

BACKGROUND

Early pathogenesis of diabetic cardiomyopathy (DMCM) may involve lipotoxicity of cardiomyocytes in the context of hyperglycemia. There are many preclinical studies of DMCM pathogenesis, but the human evidence is still poorly understood.

OBJECTIVES

By using a nondiabetic mellitus (non-DM) heart transplanted (HTX) in diabetes mellitus (DM) recipients, this study conducted a serial study of human heart transplant recipients evaluating cardiac effects of diabetic milieu (hyperglycemia and insulin resistance) on lipotoxic-mediated injury. We evaluated cardiomyocyte morpho-pathology by seriated biopsies of healthy implanted hearts in DM recipients during 12-month follow-up from HTX. Because metformin reduces ectopic lipid accumulation, we evaluated the effects of the drug in a nonrandomized subgroup.

METHODS

The DMCM-AHEAD (Diabetes and Lipid Accumulation and Heart Transplant) prospective ongoing study (NCT03546062) evaluated 158 first HTX recipients (82 non-DM, 76 DM of whom 35 [46%] were receiving metformin). HTX recipients were undergoing clinical standard evaluation (metabolic status, echocardiography, coronary computed tomography angiography, and endomyocardial biopsies). Biopsies evaluated immune response, Oil Red-O staining, ceramide, and triacylglycerol levels. Lipotoxic factors and insulin resistance were evaluated by reverse transcriptase-polymerase chain reaction.

RESULTS

There was a significant early and progressive cardiomyocyte lipid accumulation in DM but not in non-DM recipients (p = 0.019). In the subgroup receiving metformin, independently from immunosuppressive therapy that was similar among groups, lipid accumulation was reduced in comparison with DM recipients not receiving the drug (hazard ratio: 6.597; 95% confidence interval: 2.516 to 17.296; p < 0.001). Accordingly, lipotoxic factors were increased in DM versus non-DM recipients, and, relevantly, metformin use was associated with fewer lipotoxic factors.

CONCLUSIONS

Early pathogenesis of human DMCM started with cardiomyocyte lipid accumulation following HTX in DM recipients. Metformin use was associated with reduced lipid accumulation independently of immunosuppressive therapy. This may constitute a novel target for therapy of DMCM.

Maternal Obesity Affects the Glucose-Insulin Axis During the First Trimester of Human Pregnancy

Background and objective: The maternal glucose-insulin axis is central for metabolic adaptations required for a healthy pregnancy. Metabolic changes in obese mothers in early pregnancy have been scantly described. Here we characterized the glucose-insulin axis in the first trimester of human pregnancy and assessed the effect of maternal obesity and fat mass. Methods: In this cross-sectional study, maternal blood samples (N = 323) were collected during voluntary pregnancy termination (gestational age 4+0-11+6 weeks) after overnight fasting. Smokers (N = 198) were identified by self-report and serum cotinine levels (ELISA). Maternal BMI (kg/m2) and serum leptin (ELISA) were used as proxy measures of obesity and maternal fat mass, respectively. BMI was categorized into under-/normal weight (BMI < 25.0 kg/m2), overweight (BMI 25.0-29.9 kg/m2) and obese (BMI ≥ 30.0 kg/m2), and leptin in tertiles (1st tertile: leptin < 6.80 ng/ml, 2nd tertile: leptin 6.80-12.89 ng/ml, 3rd tertile: leptin > 12.89 ng/ml). ISHOMA insulin sensitivity index was calculated from glucose and C-peptide (ELISA) serum concentrations. Analyses of covariance including multiple confounders were performed to test for differences in glucose, C-peptide and ISHOMA between gestational age periods, BMI and leptin groups. C-peptide and ISHOMA were log-transformed before analyses. Results: At weeks 7-9, fasting glucose and C-peptide levels were lower (P < 0.01 and P < 0.001, respectively) and insulin sensitivity higher (P < 0.001) than at weeks 4-6. Glucose levels were not significantly different between BMI or leptin categories. In contrast, C-peptide increased by 19% (P < 0.01) between the normal weight and the overweight group and by 39% (P < 0.001) between the overweight and obese group. In the leptin groups, C-peptide increased by 25% (P < 0.001) between the 1st and 2nd leptin tertile and by 15% (P < 0.05) between the 2nd and 3rd leptin tertile. ISHOMA decreased with higher BMI and fat mass. ISHOMA decreased by 18% (P < 0.01) between the normal weight and the overweight group and by 30% (P < 0.01) between the overweight and the obese group. In the leptin groups, ISHOMA decreased by 22% (P < 0.001) between the 1st and 2nd leptin tertile and by 14% (P < 0.05) between the 2nd and 3rd leptin tertile. Conclusions: At the group level, fasting glucose, C-peptide and insulin sensitivity dynamically change in the first trimester of human pregnancy. Maternal obesity is associated with higher C-peptide and lower insulin sensitivity at all periods in the first trimester of human pregnancy, while glucose is unaltered. These findings have implications for the timing of early gestational diabetes mellitus risk screening.

Insulin resistance negatively affects bone quality not quantity: the relationship between bone and adipose tissue

The present study suggests that insulin resistance has no association with bone quantity, but quality.

INTRODUCTION

The literature has contradictory results concerning the influence of insulin resistance on bone. The present study sought to evaluate the association of insulin resistance and adipose tissue with either bone mineral density or the trabecular bone score.

METHODS

The study included 56 individuals (36 women and 20 men): age = 46.6 ± 14.2 years, weight = 67.8 ± 10.9 kg, height = 1.65 ± 0.10 m and BMI = 24.8 ± 3.9 kg/m². The investigational protocol included biochemical determinations and bone assessment by dual X-ray absorptiometry for evaluation of bone mineral density and trabecular bone score. Magnetic resonance was employed to estimate visceral, subcutaneous and bone marrow adipose tissues, as well as intrahepatic lipids.

RESULTS

The bone mineral density of the lumbar spine, femoral neck and total hip were not associated with insulin resistance-related parameters [visceral adipose tissue, intrahepatic lipids and homeostatic model assessment of insulin resistance (HOMA-IR)]. In contrast, there was a negative relationship between the trabecular bone score and all these components. The association between the trabecular bone score and HOMA-IR was reinforced after adjustment for age and BMI. Marrow adipose tissue was negatively associated with both bone mineral density and trabecular bone score.

CONCLUSIONS

The present study shows that the trabecular bone score is negatively associated with marrow adipose tissue, insulin resistance, visceral adipose tissue and intrahepatic lipid measurements. Additionally, there was a negative relationship between saturated lipids in marrow adipose tissue and the trabecular bone score. These results encourage further studies to investigate the role of the trabecular bone score exam in the clinical evaluation of osteoporosis in conditions of insulin resistance.

Elevation of the renal threshold for glucose is associated with insulin resistance and higher glycated hemoglobin levels

AIMS/INTRODUCTION

The renal threshold for glucose (RTg) corresponds to a blood glucose level of ~180 mg/dL; however, in hospitals, patients are often encountered who are hyperglycemic, but urine glucose test strip-negative, who remain negative for urine glucose even at blood glucose concentrations >180 mg/dL, implying a high RTg value. In this study, we aimed to identify factors determining high RTg in Japanese patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

We estimated RTg (eRTg) using urinalysis data from 67 type 2 diabetes mellitus patients for whom the glucose infusion rate (GIR) was determined by hyperinsulinemic-euglycemic clamp. After allocating patients to two groups according to their baseline eRTg (<180 mg/dL or ≥180 mg/dL), we identified the factors affecting eRTg using simple and multiple linear regression analyses.

RESULTS

GIR, glycated hemoglobin (HbA1c), insulin use and dyslipidemia differed significantly between the groups. In simple regression analysis, GIR, HbA1c, body muscle-to-fat ratio and insulin use were significantly correlated with eRTg; and in multiple regression analysis, GIR and HbA1c remained independent negative and positive determinants, respectively, with the contribution of GIR being substantial. In receiver operating characteristic curve analysis, when GIR <5.7 was used as the insulin resistance threshold, the cut-off value of eRTg was 189 mg/dL (P = 0.0001). Furthermore, in receiver operating characteristic analysis using eRTg ≥189 mg/dL, the cut-off value for HbA1c was 8.0% (P = 0.0006).

CONCLUSIONS

High eRTg is associated with low GIR and high HbA1c, with GIR making a substantial contribution.

Combined Aerobic and Resistance Exercise Training Reduces Circulating Apolipoprotein J Levels and Improves Insulin Resistance in Postmenopausal Diabetic Women

BACKGROUND

Circulating apolipoprotein J (ApoJ) is closely associated with insulin resistance; however, the effect of exercise on circulating ApoJ levels and the association of ApoJ with metabolic indices remain unknown. Here, we investigated whether a combined exercise can alter the circulating ApoJ level, and whether these changes are associated with metabolic indices in patients with type 2 diabetes mellitus.

METHODS

Postmenopausal women with type 2 diabetes mellitus were randomly assigned into either an exercise (EXE, n=30) or control (CON, n=15) group. Participants in the EXE group were enrolled in a 12-week program consisting of a combination of aerobic and resistance exercises. At baseline, 4, 8, and 12 weeks, body composition and metabolic parameters including homeostatic model assessment of insulin resistance (HOMA-IR) and serum ApoJ levels were assessed.

RESULTS

In the EXE group, ApoJ levels decreased 26.3% and 19.4%, relative to baseline, at 8 and 12 weeks, respectively. Between-group differences were significant at 8 and 12 weeks (P<0.05 and P<0.001, respectively). In the EXE group, 12 weeks of exercise resulted in significant decreases in body weight, percent body fat, and HOMA-IR indices. Concurrently, weight-adjusted appendicular skeletal muscle mass (ASM/wt) was increased in the EXE group compared with the CON group. Importantly, changes in the ApoJ level were significantly correlated with changes in ASM/wt.

CONCLUSION

Exercise training resulted in a significant decrease in the circulating ApoJ level, with changes in ApoJ associated with an improvement in some insulin resistance indices. These data suggest that circulating ApoJ may be a useful metabolic marker for assessing the effects of exercise on insulin resistance.

Abdominal Adiposity and Total Body Fat as Predictors of Cardiometabolic Health in Children and Adolescents With Obesity

Objective: We aimed to assess the role of adipose tissue distribution in cardiometabolic risk (in particular insulin sensitivity) in a population of children and adolescents with obesity. Methods: In this cross-sectional study, participants were 479 children and adolescents with obesity (322 boys and 157 girls) aged 3 to 18 years attending the Children's Hospital at Zhejiang University School of Medicine (Hangzhou, China). Clinical assessments included anthropometry, body composition (DXA scans), carotid artery ultrasounds, and OGTT. Insulin sensitivity was assessed using the Matsuda index. Participants were stratified into groups by sex and pubertal stage. Key predictors were DXA-derived android-to-gynoid-fat ratio (A/G) and total body fat percentage (TBF%). Results: Irrespective of sex and pubertal stage, there was a strong association between increasing A/G (i.e., greater abdominal adiposity) and lower insulin sensitivity. In multivariable models, every 0.1 increase in A/G was associated with a reduction in insulin sensitivity in prepubertal boys [-29% (95% CI -36%, -20%); p < 0.0001], pubertal boys [-13% (95% CI -21%, -6%); p = 0.001], and pubertal girls [-16% (95% CI -24%, -6%); p = 0.002]. In contrast, TBF% was not associated with insulin sensitivity when A/G was adjusted for, irrespective of pubertal stage or sex. In addition, every 0.1 increase in A/G was associated with increased likelihood of dyslipidemia in prepubertal boys [adjusted odds ratio (aOR) 1.62 (95% CI 1.05, 2.49)], impaired glucose tolerance in pubertal boys [aOR 1.64 (95% CI 1.07, 2.51)] and pubertal girls [aOR 1.81 (95% CI 1.10, 2.98)], and odds of NAFLD in both prepubertal [aOR 2.57 (95% CI 1.56, 4.21)] and pubertal [aOR 1.69 (95% CI 1.18, 2.40)] boys. In contrast, higher TBF% was only associated with higher fasting insulin and ALT in pubertal boys, being also predictive of NAFLD in this group [aOR 1.15 per percentage point (95% CI 1.06, 1.26)], but was not associated with the likelihood of other cardiometabolic outcomes assessed in any group. Conclusions: A/G is a much stronger independent predictor of cardiometabolic risk factors in children and adolescents with obesity in China, particularly glucose metabolism.

Exposure to Aroclor 1254 persistently suppresses the functions of pancreatic β-cells and deteriorates glucose homeostasis in male mice

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that have been shown to be related to the occurrence of type 2 diabetes mellitus (T2DM). Nevertheless, it is necessary to further explore the development of T2DM caused by PCBs and its underlying mechanisms. In the present study, 21-day-old C57BL/6 male mice were orally treated with Aroclor 1254 (0.5, 5, 50 or 500 μg kg^-1) once every three days. After exposure for 66 d, the mice showed impaired glucose tolerance, 13% and 14% increased fasting serum insulin levels (FSIL), and 63% and 69% increases of the pancreatic β-cell mass in the 50 and 500 μg kg^-1 groups, respectively. After stopping exposure for 90 d, treated mice returned to normoglycemia and normal FSIL. After re-exposure of these recovered mice to Aroclor 1254 for 30 d, fasting plasma glucose showed 15%, 28% and 16% increase in the 5, 50 and 500 μg kg^-1 treatments, FSIL exhibited 35%, 27%, 30% and 32% decrease in the 0.5, 5, 50 or 500 μg kg^-1 groups respectively, and there was no change in pancreatic β-cell mass. Transcription of the pancreatic insulin gene (Ins2) was significantly down-regulated in the 50 and 500 μg kg^-1 groups, while DNA-methylation levels were simultaneously increased in the Ins2 promoter during the course of exposure, recovery and re-exposure. Reduced insulin levels were initially rescued by a compensative increase in β-cell mass. However, β-cell mass eventually failed to make sufficient levels of insulin, resulting in significant increases in fasting blood glucose, and indicating the development of T2DM.

Glycated Hemoglobin, but not Insulin Sensitivity, is Associated with Memory in Subjects with Obesity

OBJECTIVE

Obesity has been related to later-life dementia. Serum glucose levels and insulin resistance are known to influence cognition in individuals with diabetes. This study aimed to evaluate memory function in middle-aged individuals with obesity in association with glucose metabolism and brain iron content.

METHODS

This was a cross-sectional case-control study including 121 participants aged 27.2 to 66.6 years (56 without obesity, 65 with obesity) stratified according to sex and menopausal status. Insulin sensitivity, body composition, brain iron content, and memory function were evaluated by euglycemic hyperinsulinemic clamp, dual-energy x-ray absorptiometry, magnetic resonance relaxometry (R2*), and California Verbal Learning Test, respectively.

RESULTS

Women with obesity, but not men, had lower scores in some California Verbal Learning Tests in association with metabolic parameters and increased brain iron content compared with controls. Fasting plasma glucose, glycated hemoglobin (HbA1c; within normal range), and R2* were negatively associated with memory scores, whereas insulin sensitivity showed positive associations. Remarkably, only HbA1c levels and R2* in the right inferior fronto-orbital region remained significant after controlling for age, sex, education, and BMI.

CONCLUSIONS

Impairments in memory function in middle-aged women with obesity are associated with HbA1c levels and brain iron content independently of insulin sensitivity. These results may have implications in the design of therapeutic strategies in women with obesity.

Optimal Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) Cut-Offs: A Cross-Sectional Study in the Czech Population

Background and Objectives: The key pathogenetic mechanism of glucose metabolism disorders, insulin resistance (IR), can be assessed using the Homeostasis Model Assessment of IR (HOMA-IR). However, its application in clinical practice is limited due to the absence of cut-offs. In this study, we aimed to define the cut-offs for the Czech population. Methods: After undergoing anthropometric and biochemical studies, the sample of 3539 individuals was divided into either nondiabetics, including both subjects with normal glucose tolerance (NGT, n = 1947) and prediabetics (n = 1459), or diabetics (n = 133). The optimal HOMA-IR cut-offs between subgroups were determined to maximize the sum of the sensitivity and specificity for diagnosing type 2 diabetes mellitus (T2DM) or prediabetes. The predictive accuracy was illustrated using receiver operating characteristic (ROC) curves. Logistic regression was performed to assess the association between a target variable (presence/absence of T2DM) depending on the HOMA-IR score as well as on the age and sex. Results: The HOMA-IR cut-off between nondiabetics and diabetics for both sexes together was 3.63, with a sensitivity of 0.56 and a specificity of 0.86. The area under the ROC curve was 0.73 for T2DM diagnosing in both sexes. The HOMA-IR cut-off between the NGT subjects and prediabetics was 1.82, with a sensitivity of 0.60 and a specificity of 0.66. Logistic regression showed that increased HOMA-IR is a risk factor for the presence of T2DM (odds ratio (OR) 1.2, 95% confidence interval (CI) 1.14–1.28, p < 0.0001). The predictive ability of HOMA-IR in diagnosing T2DM is statistically significantly lower in females (OR 0.66, 95% CI 0.44–0.98). The results are valid for middle-aged European adults. Conclusions: The results suggest the existence of HOMA-IR cut-offs signaling established IR. Introduction of the instrument into common clinical practice, together with the known cut-offs, may contribute to preventing T2DM.

Systematic review and meta-analysis on the association between phthalates exposure and insulin resistance

This study aims to provide an overview of human studies on the association of exposure to phthalates and insulin resistance. We systematically searched human studies available until 15 January 2018.We conducted a literature search in Scopus, ISI Web of Science, PubMed, Google Scholar, and Cochrane Collaboration. We used the following keywords to identify relevant articles: "phthalate", "phthalate ester", "metabolic syndrome", "insulin resistance", "glucose intolerance", and "diabetes". For analyzing data, we conducted meta-analysis using the Stata software. We appraised each study to examine the sources of heterogeneity, including difference in clinical outcomes and exposure measurements. To determine the robustness and whether some of the factors have the highest impact on the results of the present meta-analysis, several sensitivity analyses were conducted. Sensitivity analysis showed that by removing studies with the highest weight and age groups, no change was observed in heterogeneity. Moreover, with excluding the study conducted in Europe, the results remained unchanged and constant. In addition, the funnel plot and Egger's tests were executed to access publication bias. Both the funnel plots and Egger's test did not show any evidence of publication bias (P = 0.31). In the random effects meta-analysis of all studies (n = 8), the pooled correlation coefficient between phthalate exposure and HOMA-IR was 0.10 (95% CI; 0.07-0.12, P < 0.001), with significant heterogeneity (P < 0.001, I² = 85.5%). Our findings revealed positive association between exposure to phthalate metabolites and increased HOMA-IR; this association remained significant even after adjusting the analysis for multiple confounding variables.

Insulin Resistance as a Risk Factor for Cutaneous Melanoma. A Case Control Study and Risk-Assessment Nomograms

Insulin resistance and obesity are suggested to have a key role in the molecular pathogenesis of various disorders, including several malignancies. Moreover, insulin resistance has recently been found to be associated with cutaneous and uveal melanoma, while a variable positive correlation between obesity and the risk of cutaneous melanoma was also found at least in men. The present trial aims at confirming whether insulin resistance, assessed with the homeostasis model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI), is a risk factor for cutaneous melanoma. One hundred and thirty patients diagnosed with cutaneous melanoma and 130 age-, sex-, and skin phototype-matched controls were evaluated. At the univariate and multivariate analysis, the diagnosis of cutaneous melanoma was inversely related with insulin resistance (HOMA-IR) and positively with BMI (p = 0.0014 and p = 0.008, respectively). Consistently, insulin sensitivity (QUICKI) and BMI resulted positively associated with the diagnosis of cutaneous melanoma (p = 0.0001 and p = 0.0026, respectively). The results obtained are partially in agreement with those reported in the literature. By comparing our data with those generated by other studies, inconsistencies in key features among subgroups of different trials have emerged, possibly affecting final correlations. Based on insulin resistance/sensitivity, fasting insulinemia/glycemia, and BMI values collected from patients who participated in the present trial, two nomograms potentially assessing the risk of cutaneous melanoma have been generated. Molecular aspects sustain a role for insulin resistance in the carcinogenesis of cutaneous melanoma, but clinical data remain uncertain. Larger, well-balanced, correlative trials are still needed to define the potential role of insulin resistance in the carcinogenesis of cutaneous melanoma.

Factors influencing insulin sensitivity during hyperinsulinemic-euglycemic clamp in healthy Korean male subjects

Background and objective: The effects of age and related factors on insulin sensitivity have not been definitively evaluated in East Asian populations. We proposed a reference range for the glucose disposal rate (M-value) on hyperinsulinemic-euglycemic study and its association with other parameters. Methods: Healthy, non-diabetic young (n=10) and elderly (n=13) male subjects with normal body mass index were eligible for this study. Subjects who passed the oral glucose tolerance test (OGTT) underwent hyperinsulinemic-euglycemic clamp with high-dose (80 mU/m²·min) insulin infusion. Results: M-values were normalized to body weight (M_BW) and fat-free mass (M_FFM). Neither M-value was significantly different between age groups (P=0.458 and P=0.900, respectively). An inverse correlation was observed between M_FFM and baseline insulin (r=-0.418; P=0.047), baseline C-peptide (r=-0.426; P=0.043) and OGTT 2-hour glucose (r=-0.452; P=0.030). Regarding correlations with other insulin sensitivity indices, M-values were positively associated with the Matsuda index but not with homeostasis model assessment of insulin resistance. Conclusion: Our results suggest that age is not a critical determinant of insulin sensitivity, while fasting insulin and C-peptide levels, OGTT 2-hour glucose level, and Matsuda index are predictable markers of insulin sensitivity in healthy Koreans.

Body mass index ≥23 is a risk factor for insulin resistance and diabetes in Japanese people: A brief report

Background

Screening for undiagnosed type 2 diabetes mellitus is recommended for Asian Americans with a body mass index ≥23. However, the optimal body mass index cut-off score for predicting the risk of diabetes mellitus in Japanese people is not well known. The aim of this study was to determine the best body mass index cut-off score for predicting insulin resistance and diabetes mellitus in the Japanese population.

Methods

This study had two parts, a clinical investigation and a retrospective observational investigation. In the clinical part of the study, 58 participants (26 with type 2 diabetes mellitus and 32 non-diabetics) underwent a hyperinsulinemic-euglycemic clamp from which their glucose disposal rate was measured. For the retrospective part of the study, medical check-up data from 88,305 people in the Tottori Prefecture were analyzed for clinical evidence of diabetes mellitus. The optimal BMI cut-off scores for prediction of insulin resistance and diabetes mellitus were determined.

Results

In the clamp study, the optimal body mass index cut-off score to predict insulin resistance in non-diabetic patients was 22.7. All participants with type 2 diabetes mellitus were insulin resistant, and the optimal body mass index cut-off score for prediction of severe insulin resistance was 26.2. When the data from the type 2 diabetic and the non-diabetic participants were combined, the optimal body mass index cut-off score for prediction of insulin resistance was 23.5. Analysis of 88,305 medical check-up records yielded an optimal body mass index cut-off score for prediction of diabetes mellitus of 23.6.

Conclusions

These results suggest that having a body mass index ≥23 is a risk factor for insulin resistance and diabetes mellitus in the Japanese population.

Increased insulin sensitivity in individuals with neurofibromatosis type 1

Objects To compare insulin resistance (IR) and metabolic aspects of patients with neurofibromatosis type 1 (NF1) and individuals without the disease. Subjects and methods Forty patients with NF1 were matched by sex, age, and body mass index (BMI) to 40 controls from the community. Blood samples were collected for biochemical assessment. Homeostasis model assessment adiponectin (HOMA-AD), Homeostasis model assessment insulin resistance (HOMA-IR), and adiponectin/leptin ratio (ALR) were used to identify IR. Results The median HOMA-IR values were similar between the groups. However, the HOMA-AD value was significantly lower and the ALR significantly higher in the NF1 group. Fasting blood glucose (FBG), leptin, and visfatin levels of patients with NF1 were significantly lower, although adiponectin levels were significantly higher than those in the controls. Fasting insulin and blood glucose levels 2 hours after administration of 75 g of dextrose, glycated hemoglobin, and resistin showed no significant differences between groups. The HOMA-AD correlated with BMI, FBG, blood glucose levels 2 hours after administration of 75 g of dextrose, fasting insulin, glycated hemoglobin, adiponectin, leptin, visfatin, ALR, and HOMA-IR. The ALR correlated with BMI leptin, visfatin, and adiponectin. Conclusions Lower levels of FBG, leptin, visfatin, and HOMA-AD, and higher adiponectin levels and ALR may be related to increased insulin sensitivity and lower occurrence of type 2 diabetes mellitus in patients with NF1.

CPR-IR is an insulin resistance index that is minimally affected by hepatic insulin clearance-A preliminary research

Background

Increased hepatic insulin clearance (HIC) is important in the pathophysiology of type 2 diabetes mellitus (T2DM). The aim of this study is to analyze an effective insulin resistance (IR) index that is minimally affected by HIC.

Methods

Our study involved 20 participants with T2DM and 21 healthy participants without diabetes (Non-DM). Participants underwent a meal tolerance test from which plasma glucose, insulin and serum C-peptide immunoreactivity (CPR) were measured, and HOMA-IR and HIC were calculated. Participants then underwent a hyperinsulinemic-euglycemic clamp from which the glucose disposal rate (GDR) was measured.

Results

The index CPR-IR = 20/(fasting CPR × fasting plasma glucose) was correlated more strongly with GDR, than was HOMA-IR, and CPR-IR could be used to estimate GDR. In T2DM participants with HIC below the median, HOMA-IR and CPR-IR were equally well correlated with GDR. In T2DM with high HIC, CPR-IR correlated with GDR while HOMA-IR did not. In Non-DM, CPR-IR and HOMA-IR were equally well correlated with GDR regardless of HIC. The mean HIC value in T2DM was significantly higher than that of Non-DM.

Conclusions

CPR-IR could be a simple and effective index of insulin resistance for patients with type 2 diabetes that is minimally affected by HIC.

Insulin Sensitivity and Glucose Homeostasis Can Be Influenced by Metabolic Acid Load

Recent epidemiological findings suggest that high levels of dietary acid load can affect insulin sensitivity and glucose metabolism. Consumption of high protein diets results in the over-production of metabolic acids which has been associated with the development of chronic metabolic disturbances. Mild metabolic acidosis has been shown to impair peripheral insulin action and several epidemiological findings suggest that metabolic acid load markers are associated with insulin resistance and impaired glycemic control through an interference intracellular insulin signaling pathways and translocation. In addition, higher incidence of diabetes, insulin resistance, or impaired glucose control have been found in subjects with elevated metabolic acid load markers. Hence, lowering dietary acid load may be relevant for improving glucose homeostasis and prevention of type 2 diabetes development on a long-term basis. However, limitations related to patient acid load estimation, nutritional determinants, and metabolic status considerably flaws available findings, and the lack of solid data on the background physiopathology contributes to the questionability of results. Furthermore, evidence from interventional studies is very limited and the trials carried out report no beneficial results following alkali supplementation. Available literature suggests that poor acid load control may contribute to impaired insulin sensitivity and glucose homeostasis, but it is not sufficiently supportive to fully elucidate the issue and additional well-designed studies are clearly needed.

Metabolic clustering of risk factors: evaluation of Triglyceride-glucose index (TyG index) for evaluation of insulin resistance

BACKGROUND

Metabolic syndrome over the years have structured definitions to classify an individual with the disease. Literature review suggests insulin résistance is hallmark of these metabolic clustering. While measuring insulin resistance directly or indirectly remains technically difficult in general practice, along with multiple stability issues for insulin, various indirect measures have been suggested by authorities. Fasting triglycerides-glucose (TyG) index is one such marker, which is recently been suggested as a useful diagnostic marker to predict metabolic syndrome. However, limited data is available on the subject with almost no literature from our region on the subject.

OBJECTIVE

1. To correlate TyG index with insulin resistance, anthropometric indices, small dense LDLc, HbA1c and nephropathy. 2. To evaluate TyG index as a marker to diagnose metabolic syndrome in comparison to other available markers.

DESIGN-CROSS-SECTIONAL ANALYSIS

Place and duration of study-From Jun-2016 to July-2017 at PSS HAFEEZ hospital Islamabad.

SUBJECTS AND METHODS

From a finally selected sample size of 227 male and female subjects we evaluated their anthropometric data, HbA1c, lipid profile including calculated sdLDLc, urine albumin creatinine raito(UACR) and insulin resistance (HOMAIR). TyG index was calculated using formula of Simental-Mendía LE et al. Aforementioned parameters were correlated with TyG index, differences between subjects with and without metabolic syndrome were calculated using Independent sample t-test. Finally ROC curve analysis was carried out to measure AUC for candidate parameters including TyG Index for comparison.

RESULTS

TyG index in comparison to other markers like fasting triglycerides, HOMAIR, HDLc and non-HDLc demonstrated higher positive linear correlation with BMI, atherogenic dyslipidemia (sdLDLc), nephropathy (UACR), HbA1c and insulin resistance. TyG index showed significant differences between various markers among subjects with and without metabolic syndrome as per IDF criteria. AUC (Area Under Curve) demonstrated highest AUC for TyG as [(0.764, 95% CI 0.700-0.828, p-value ≤ 0.001)] followed by fasting triglycerides [(0.724, 95% CI 0.656-0.791, p-value ≤ 0.001)], sdLDLc [(0.695, 95% CI 0.626-0.763, p-value ≤ 0.001)], fasting plasma glucose [(0.686, 95% CI 0.616-0.756, p-value ≤ 0.001)], Non-HDLc [(0.640, 95% CI 0.626-0.763, p-value ≤ 0.001)] and HOMAIR [(0.619, 95% CI 0.545-0.694, p-value ≤ 0.001)].

CONCLUSION

TyG index, having the highest AUC in comparison to fasting glucose, triglycerides, sdLDLc, non-HDLc and HOMAIR can act as better marker for diagnosing metabolic syndrome.