The cut-off values of surrogate measures for insulin resistance in the Korean population according to the Korean Genome and Epidemiology Study (KOGES)

Relationship Between Body Composition and Insulin Resistance Evaluated by the TyG Index: A Retrospective Study Among Chinese Population

OBJECTIVE

The triglyceride glucose (TyG) index, a novel and easily obtained marker of insulin resistance (IR), has been shown to predict metabolic diseases. Monitoring body composition is crucial in assessing disease states. This study aimed to investigate the relationship between body composition and IR as assessed by the TyG index.

METHODS

Between January 2018 and December 2021, 12,186 individuals were initially enroled, with 4061 adults were ultimately included. Body composition, including fat mass (FM), fat mass index (FMI), fat-free mass (FFM), fat-free mass index (FFMI), and percent body fat (PBF), was measured using bioelectrical impedance analysis. Spearman analysis assessed correlations between body composition indices and the TyG index. Binary logistic regression identified independent predictors of IR.

RESULTS

Older women (≥ 50 years old) showed significantly higher BMI, PBF, FM, FMI, FFMI, HOMA-IR, and the TyG index, but lower FFM compared to younger women; Older men exhibited significantly lower BMI, FM, FFM, FFMI, HOMA-IR, and the TyG index than the younger men. FM, FMI, FFM, FFMI, and PBF were positively correlated with the TyG index. FFMI and PBF significantly predicted IR in both genders. Combined FFMI and PBF yielded an area under the ROC curves of 0.718 in women and 0.661 in men for IR diagnosis.

CONCLUSION

The TyG index correlates with body composition parameters of FFMI and PBF as well as HOMA-IR potentially making it a convenient marker of metabolic risk.

The Genetic Variants Influencing Hypertension Prevalence Based on the Risk of Insulin Resistance as Assessed Using the Metabolic Score for Insulin Resistance (METS-IR)

Insulin resistance is a major indicator of cardiovascular diseases, including hypertension. The Metabolic Score for Insulin Resistance (METS-IR) offers a simplified and cost-effective way to evaluate insulin resistance. This study aimed to identify genetic variants associated with the prevalence of hypertension stratified by METS-IR score levels. Data from the Korean Genome and Epidemiology Study (KoGES) were analyzed. The METS-IR was calculated using the following formula: ln [(2 × fasting blood glucose (FBG) + triglycerides (TG)) × body mass index (BMI)]/ ln [high-density lipoprotein cholesterol (HDL-C)]. The participants were divided into tertiles 1 (T1) and 3 (T3) based on their METS-IR scores. Genome-wide association studies (GWAS) were performed for hypertensive cases and non-hypertensive controls within these tertile groups using logistic regression adjusted for age, sex, and lifestyle factors. Among the METS-IR tertile groups, 3517 of the 19,774 participants (17.8%) at T1 had hypertension, whereas 8653 of the 20,374 participants (42.5%) at T3 had hypertension. A total of 113 single-nucleotide polymorphisms (SNPs) reached the GWAS significance threshold (p < 5 × 10-8) in at least one tertile group, mapping to six distinct genetic loci. Notably, four loci, rs11899121 (chr2p24), rs7556898 (chr2q24.3), rs17249754 (ATP2B1), and rs1980854 (chr20p12.2), were significantly associated with hypertension in the high-METS-score group (T3). rs10857147 (FGF5) was significant in both the T1 and T3 groups, whereas rs671 (ALDH2) was significant only in the T1 group. The GWASs identified six genetic loci significantly associated with hypertension, with distinct patterns across METS-IR tertiles, highlighting the role of metabolic context in genetic susceptibility. These findings underscore critical genetic factors influencing hypertension prevalence and provide insights into the metabolic-genetic interplay underlying this condition.

The triglyceride-glucose index as an indicator of latent atherogenicity of the plasma lipid profile in healthy men with normolipidaemia

OBJECTIVES

The triglyceride-glucose (TyG) index is a novel diagnostic marker for various metabolic and cardiovascular diseases. However, little is known about the association of the TyG index with plasma atherogenicity, especially with its latent forms. The aim of this study was to assess the potential of the use of the TyG index as a marker of atherogenic risk.

METHODS

A total of 202 men with normolipidaemia, aged 20-60 years, were enrolled in this study. Fasting biochemical parameters were measured. The TyG index was calculated as ln[triglyceride(mg/dL)×glucose(mg/dL)]/2. The diagnostic ability of the TyG index for detecting atherogenic risk was tested by receiver operating characteristic (ROC) curve analysis.

RESULTS

A substantial portion of normolipidaemic men had deviations from the reference values for the indices calculated using apolipoproteins. Unfavorable values for the apolipoprotein (apo) B/apoA-I ratio, low-density lipoprotein cholesterol/apoB (LDL-C/apoB) ratio, and the atherogenic index (ATH index) were observed in 32.7%, 31.7%, and 14.4% of men, respectively. The results of ROC curve analysis showed that the TyG index had good diagnostic ability for identifying unfavorable apolipoprotein indices in normolipidaemic men.

CONCLUSIONS

Thus, the TyG index can be a valuable additional marker for assessing latent atherogenic risk; it can provide useful information for the diagnosis and treatment of early atherosclerosis.

Biomarkers of insulin sensitivity/resistance

In recent years, remarkable advancements in elucidating the intricate molecular underpinnings of type 2 diabetes mellitus (T2D) have been achieved. Insulin resistance (IR) has been unequivocally acknowledged as the driving pathogenetic mechanism of T2D, preceding disease onset by several years. Nonetheless, diagnostic tools for ascertaining IR are lacking in current clinical practice, representing a critical unmet need; use of the hyperinsulinemic-euglycemic glucose clamp, widely accepted as the gold standard method for evaluating IR at present, is cumbersome in a clinical setting. Thus, the development of well-validated, reliable, and affordable biomarkers of IR has attracted considerable attention from the research community. The biomarkers under investigation can be divided into two major categories: (1) indices or ratios, comprising parameters obtained from a basic or comprehensive metabolic panel and/or derived from anthropometric measurements, and (2) circulating molecules implicated in pathophysiological processes associated with IR. Furthermore, numerous novel biomarkers, including markers of β-cell dysfunction, radiographic quantification of excess visceral adipose tissue, T2D prediction models, certain microRNAs and metabolomic biomarkers, have also provided promising preliminary results. This narrative review aims to present current evidence pertaining to the most notable and exciting biomarkers of IR that are under rigorous evaluation.

Diagnostic and prognostic value of triglyceride glucose index: a comprehensive evaluation of meta-analysis

OBJECTIVE

The present umbrella review aims to collate and summarize the findings from previous meta-analyses on the Triglyceride and Glucose (TyG) Index, providing insights to clinicians, researchers, and policymakers regarding the usefulness of this biomarker in various clinical settings.

METHODS

A comprehensive search was conducted in PubMed, Scopus, and Web of Science up to April 14, 2024, without language restrictions. The AMSTAR2 checklist assessed the methodological quality of the included meta-analyses. Statistical analyses were performed using Comprehensive Meta-Analysis (CMA) software.

RESULTS

A total of 32 studies were finally included. The results revealed significant associations between the TyG index and various health outcomes. For kidney outcomes, a high TyG index was significantly associated with an increased risk of contrast-induced nephropathy (CIN) (OR = 2.24, 95% CI: 1.82-2.77) and chronic kidney disease (CKD) (RR = 1.46, 95% CI: 1.32-1.63). High TyG index was significantly associated with an increased risk of type 2 diabetes mellitus (T2DM) (RR = 3.53, 95% CI: 2.74-4.54), gestational diabetes mellitus (GDM) (OR = 2.41, 95% CI: 1.48-3.91), and diabetic retinopathy (DR) (OR = 2.34, 95% CI: 1.31-4.19). Regarding metabolic diseases, the TyG index was significantly higher in patients with obstructive sleep apnea (OSA) (SMD = 0.86, 95% CI: 0.57-1.15), metabolic syndrome (MD = 0.83, 95% CI: 0.74-0.93), and non-alcoholic fatty liver disease (NAFLD) (OR = 2.36, 95% CI: 1.88-2.97) compared to those without these conditions. In cerebrovascular diseases, a higher TyG index was significantly associated with an increased risk of dementia (OR = 1.14, 95% CI: 1.12-1.16), cognitive impairment (OR = 2.31, 95% CI: 1.38-3.86), and ischemic stroke (OR = 1.37, 95% CI: 1.22-1.54). For cardiovascular outcomes, the TyG index showed significant associations with an increased risk of heart failure (HF) (HR = 1.21, 95% CI: 1.12-1.30), atrial fibrillation (AF) (SMD = 1.22, 95% CI: 0.57-1.87), and hypertension (HTN) (RR = 1.52, 95% CI: 1.25-1.85).

CONCLUSION

The TyG index is a promising biomarker for screening and predicting various medical conditions, particularly those related to insulin resistance and metabolic disorders. However, the heterogeneity and methodological quality of the included studies suggest the need for further high-quality research to confirm these findings and refine the clinical utility of the TyG index.

The association of shift work and TyG index among male workers in a chemical plant of Korea: a cross-sectional study

Background

Disturbance of circadian rhythms caused by shift work has adverse effects on insulin resistance. Many previous studies have confirmed that shift work and insulin resistance are related using homeostasis model assessment-insulin resistance, one of the insulin resistance indicators. However, the triglycerides and glucose index (TyG index) has recently been studied as an insulin resistance indicator. The aim of this study is to investigate the association of shift work and TyG index, one of the indirect indicators of insulin resistance, using results of health checkups in one workplace.

Methods

Based on medical examination data collected in February 2019, a total of 3,794 subjects from one chemical plant in Korea were selected for this study. Cut-off value of TyG index for predicting development of diabetes mellitus (DM) was 4.69. A multiple logistic regression analysis was performed after adjusting for age, employment period, obesity, abdominal obesity, smoking, drinking, physical activity, hypertension, stroke, heart disease.

Results

As a result of logistic regression analysis, compared to day workers, odds ratio (OR) with a TyG index above cut-off value for predicting development of DM in shift workers was 1.220 after adjusting for age, employment period, obesity, abdominal obesity, smoking, drinking, physical activity, hypertension, stroke, heart disease (Model 1, OR: 1.276; 95% confidence interval [CI]: 1.099-1.482; Model 2, OR: 1.232; 95% CI: 1.055-1.438; Model 3, OR: 1.220, 95% CI: 1.030-1.444).

Conclusions

There was a significant association between shift work and TyG index among male workers in a chemical plant. More research studies on the association between shift work and TyG index are needed in the future.

Triglyceride glucose-related indexes and lipid accumulation products-reliable markers of insulin resistance in the Chinese population

Background

Insulin resistance (IR) is a pivotal pathogenic component of metabolic diseases. It is crucial to identify convenient and reliable indicators of insulin resistance for its early detection. This study aimed at assessing the predictive ability of seven novel obesity and lipid-related indices.

Methods

A total of 5,847 female and 3,532 male healthy subjects were included in the study. The triglyceride glucose (TyG) index, TyG-body mass index (TyG-BMI), TyG-waist circumference (TyG-WC), lipid accumulation products (LAP), body roundness index (BRI), body adiposity index (BAI), and visceral adiposity index (VAI) were measured and calculated using the established formulae. IR was diagnosed using the homeostatic model assessment of insulin resistance (HOMA-IR) index over the third quantile.

Results

The levels of all seven lipid-related indices were significantly higher in subjects with higher HOMA-IR values than in those with lower HOMA-IR values. These indices displayed moderate to high effectiveness [receiver operating characteristic (ROC) curve-area under the curve (AUC) > 0.6] in predicting IR. Among them, TyG-BMI (AUC: 0.729), LAP (AUC: 0.708), and TyG-WC (AUC: 0.698) showed the strongest association with HOMA-IR. In the female population, the AUC for TyG-BMI, LAP, and TyG-WC in predicting IR was 0.732, 0.705, and 0.718, respectively. Logistic regression analysis showed the optimal cut-off values of those indicators in predicting IR as follows: TyG-BMI: male subjects - 115.16 [odds ratio (OR) = 6.05, 95% CI: 5.09-7.19], female subjects - 101.58 (OR = 4.55, 95% CI: 4.00-5.16); LAP: male subjects - 25.99 (OR = 4.53, 95% CI: 3.82-5.38), female subjects - 16.11 (OR = 3.65, 95% CI: 3.22-4.14); and TyG-WC: male subjects - 409.43 (OR = 5.23, 95% CI: 4.48-6.24), female subjects - 342.48 (OR = 4.07, 95% CI: 3.59-4.61).

Conclusion

TyG-index-related parameters and LAP appear to be effective predictors of IR in the Chinese population. Specifically, TyG-BMI may be the most appropriate predictor of IR.

[Construction of a Predictive Model for Diabetes Mellitus Type 2 in Middle-Aged and Elderly Populations Based on the Medical Checkup Data of National Basic Public Health Service]

Objective

To establish a universally applicable logistic risk prediction model for diabetes mellitus type 2 (T2DM) in the middle-aged and elderly populations based on the results of a Meta-analysis, and to validate and confirm the efficacy of the model using the follow-up data of medical check-ups of National Basic Public Health Service.

Methods

Cohort studies evaluating T2DM risks were identified in Chinese and English databases. The logistic model utilized Meta-combined effect values such as the odds ratio (OR) to derive β, the partial regression coefficient, of the logistic model. The Meta-combined incidence rate of T2DM was used to obtain the parameter α of the logistic model. Validation of the predictive performance of the model was conducted with the follow-up data of medical checkups of National Basic Public Health Service. The follow-up data came from a community health center in Chengdu and were collected between 2017 and 2022 from 7602 individuals who did not have T2DM at their baseline medical checkups done at the community health center. This community health center was located in an urban-rural fringe area with a large population of middle-aged and elderly people.

Results

A total of 40 cohort studies were included and 10 items covered in the medical checkups of National Basic Public Health Service were identified in the Meta-analysis as statistically significant risk factors for T2DM, including age, central obesity, smoking, physical inactivity, impaired fasting glucose, a reduced level of high-density lipoprotein cholesterol (HDL-C), hypertension, body mass index (BMI), triglyceride glucose (TYG) index, and a family history of diabetes, with the OR values and 95% confidence interval (CI) being 1.04 (1.03, 1.05), 1.55 (1.29, 1.88), 1.36 (1.11, 1.66), 1.26 (1.07, 1.49), 3.93 (2.94, 5.24), 1.14 (1.06, 1.23), 1.47 (1.34, 1.61), 1.11 (1.05, 1.18), 2.15 (1.75, 2.62), and 1.66 (1.55, 1.78), respectively, and the combined β values being 0.039, 0.438, 0.307, 0.231, 1.369, 0.131, 0.385, 0.104, 0.765, and 0.507, respectively. A total of 37 studies reported the incidence rate, with the combined incidence being 0.08 (0.07, 0.09) and the parameter α being -2.442 for the logistic model. The logistic risk prediction model constructed based on Meta-analysis was externally validated with the data of 7602 individuals who had medical checkups and were followed up for at least once. External validation results showed that the predictive model had an area under curve (AUC) of 0.794 (0.771, 0.816), accuracy of 74.5%, sensitivity of 71.0%, and specificity of 74.7% in the 7602 individuals.

Conclusion

The T2DM risk prediction model based on Meta-analysis has good predictive performance and can be used as a practical tool for T2DM risk prediction in middle-aged and elderly populations.

Association between experience of insulin resistance and long-term cardiovascular disease risk: findings from the Korean Genome and Epidemiology Study (KOGES)

PURPOSE

Although the correlation between insulin resistance (IR) and cardiovascular disease (CVD) risk is well-established, the impact of changes in IR status over time has received little attention. This study aimed to investigate the effect of IR on CVD risk in a large prospective cohort of middle-aged Korean adults.

METHODS

We assessed 3597 participants from the Korean Genome and Epidemiology Study (KoGES). Participants were categorized as having IR if their HOMA-IR was ≥2.5 at least once during the exposure period. Multivariate Cox proportional hazards regression analysis was performed to assess hazard ratios (HRs) with 95% CIs for incident CVD after adjusting for confounders.

RESULTS

Among a total of 3597 participants, 2259 did not have IR and 1138 had IR. The cumulative incidence rate of CVD in the IR group was significantly higher than that in the non-IR group (log-rank test, p = 0.015). Compared to the non-IR group, the HR and 95% CI for incident CVD in the IR group was 1.40 (1.07-1.83) in the unadjusted model. The presence of IR during the exposure period was significantly associated with a higher risk of incident CVD after adjusting for age, sex, body mass index, diabetes, hypertension, dyslipidemia, C-reactive protein, physical activity, alcohol intake, and smoking status (HR = 1.37; 95% CI: 1.01-1.84).

CONCLUSION

Individuals who have experienced IR have a consistently higher likelihood of developing CVD than those who have never had IR. More intensive efforts should be made to prevent IR in middle-aged and older adults.

Association between the triglyceride glucose index and chronic total coronary occlusion: A cross-sectional study from southwest China

BACKGROUND AND AIM

Insulin resistance (IR) plays an important role in the atherosclerotic process, and the triglyceride glucose (TyG) index is a reliable indicator of IR and is strongly associated with cardiovascular disease. However, there are few studies regarding the relationship between the TyG index and chronic total coronary occlusion (CTO). Herein, the correlation between the TyG index and CTO, as well as their interactions with other traditional cardiovascular risk factors, were investigated.

METHODS AND RESULTS

We enrolled 2691 patients who underwent coronary angiography at Guangyuan Central Hospital from January 2019 to October 2021. TyG index results were used to create three groups using the trichotomous method. CTO was defined as complete occlusion of the coronary artery for ≥3 months. Univariate and multivariate logistic regression models, restricted cubic splines, receiver operating characteristic (ROC) curves, and subgroup analyses was performed. A significant correlation between the TyG index and CTO was noted. The risk of CTO was increased 2.09-fold in the group with the highest TyG compared with the lowest (OR, 2.09; 95 % CI, 1.05-4.17; P = 0.036). In addition, there was a linear dose-response relationship between the TyG index and CTO (nonlinear P = 0.614). The area under the ROC curve was 0.643 (95 % CI, 0.572-0.654). Using subgroup analyses, we observed that the TyG index was associated with a significantly higher risk of CTO in males and smokers.

CONCLUSIONS

An elevated TyG index was related to the risk of CTO and may constitute a meaningful predictor of CTO, particularly in males and in smokers.

Does excess body weight accelerate immune aging?

BACKGROUND

Overweight and obesity in older adults increase the risk of a range of comorbidities by sustaining chronic inflammation and thus enhancing immunosenescence. This study aimed to assess whether excess body mass affected disproportion in T lymphocytes. Therefore, the study was designed to explain whether excess body mass in older individuals affected the disproportion in numbers of T lymphocytes and whether anthropometric indices and immune risk profile expressed as CD4/CD8 ratio are diagnostically useful in the analysis of immunosenescence.

MATERIALS & METHODS

One hundred three individuals aged 73.6 ± 3.1 years were allocated to the normal body mass (body mass index (BMI) 18.5-24.9 kg/m2,n = 39), the pre-obesity (BMI 25.0-29.9 kg/m2, n = 44) or the obesity (BMI ≥30.0 kg/m2, n = 20) group, based on WHO recommendations. Details on the subjects' medical history and lifestyle were obtained by health questionnaire. Anthropometric analysis was performed by bioelectrical impedance method, biochemical analysis was made by the automatic analyzer and ELISA immunoassays, and T and B lymphocyte counts were determined by eight-parameter flow cytometry. Additionally, visceral adiposity index, body adiposity index (BAI), and body shape index (ABSI) were evaluated based on body circumference, BMI and lipid-lipoprotein profile measurements.

RESULTS

The highest percentage of CD3+CD4+ T lymphocytes (59.4 ± 12.6 %) and the lowest CD3+CD8+ T lymphocytes (31.6 ± 10.0 %) were noted in patients the obesity group. The highest cut-off value of 1.9 for CD4/CD8 ratio was recorded in the normal body mass vs pre-obesity model. CD4/CD8 ratio > 2.5 was recorded in >20 % of our pre-obesity and obesity groups while 64.5 % of the normal body mass group had CD4/CD8 ratio < 1. High diagnostic usefulness was demonstrated for both BAI and lipid accumulation product (LAP) (AUC values of ~0.800 and ~ 0.900 respectively) in three models: normal body mass vs pre-obesity, normal body mass vs obesity, and pre-obesity vs obesity.

CONCLUSION

The odds ratios (OR) for CD4/CD8 ratio in the normal body mass vs obesity model (OR = 16.1, 95%CI 3.8-93.6) indicated a potential diagnostic value of T lymphocytes for clinical prognosis of immune aging in relation to excess body weight in older adults. High values of AUC obtained for the following models: CD4/CD8 + BAI (AUC = 0.927), CD4/CD8 + LAP (AUC = 1.00), CD4/CD8 + ABSI (AUC = 0.865) proved to provide excellent discrimination between older adults with obesity and with normal body mass.

Evaluation of insulin secretion and insulin sensitivity in pregnant women: Application value of simple indices

The prevalence of gestational diabetes mellitus (GDM) is increasing annually, which poses substantial harm to the health of both mothers and children. Therefore, selection of clinically applicable and easily detectable indicators in the assessment of maternal insulin secretory function and insulin sensitivity in pregnant women undoubtedly holds great importance in evaluating the risk of GDM, guiding the choice of GDM therapy modalities, and improving the ability to provide early warning of adverse pregnancy outcomes. Compared with the classic clamp technique, many simple indices are more suited for use among pregnant women due to the low frequency of blood sampling and simple administration involved. While indices derived from fasting blood glucose and fasting insulin levels are most readily available, they are unable to provide information on the ability of insulin to manage the glucose load during pregnancy. Although the indices derived from the insulin and glucose values at each time point of the oral glucose tolerance test can provide a more comprehensive picture of the insulin sensitivity and insulin secretory function of the body, their application is constrained by the complexity of the procedure and associated high costs. Concomitantly, the findings from different studies are influenced by a variety of confounding factors, such as the gestational age during testing, race, and detection method. Furthermore, insulin secretory function and insulin sensitivity in pregnant women differ from those in non-pregnant women in that they change significantly with prolonged pregnancy; hence, there is an urgent need to develop a pregnancy-specific reference range. This article reviews the progress in the application of simple indices to help clinicians better understand their potential application in detecting GDM.

Association of cardiometabolic factors and insulin resistance surrogates with mortality in participants from the Korean Genome and Epidemiology Study

BACKGROUND

Simple biochemical and anthropometric measurements such as fasting blood glucose (FBG), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), waist circumference (WC), and body mass index (BMI) are used to formulate insulin resistance (IR) indices. Whether these indices provide new predictive information for mortality remains unknown. This study examined the relationships of biochemical, anthropometric, and IR indices with mortality risk, as well as their predictive performance.

METHODS

The data source was the Korean Genome and Epidemiology Study (2004-2020) involving 114,957 participants whose data were linked to death records. The IR indices- triglyceride-glucose index (TyG), TyG-BMI, TyG-WC, visceral adiposity index (VAI), lipid accumulation product (LAP), and metabolic score for insulin resistance (METS-IR) were computed using standard formulae. The associations were examined using restricted cubic splines. The predictive performance was compared using the log-likelihood ratio chi-square test.

RESULTS

Body mass index was U-shaped, HDL-C was reverse J-shaped, and FBG and TG levels were J-shaped associated with all-cause mortality. Results showed U-shaped (TyG), J-shaped (TyG-BMI, VAI, LAP, and METS-IR), and reverse J-shaped (TyG-WC) associations with all-cause mortality. The percentages of new predictive information for all-cause mortality explained by the FBG level, BMI, TyG-BMI, and METIR were 3.34%, 2.33%, 1.47%, and 1.37%, respectively. Other IR indices and biochemical and anthropometric measurements provided < 1.0% of new predictive information. For cardiovascular disease mortality, the FBG, BMI, METIR, TyG-BMI, and HDL-C levels explained 2.57%, 2.12%, 1.59%, 1.30%, and 1.27% of new predictive information respectively. Moreover, the risks of cancer mortality explained by FBG level, VAI, and HDL-C level were 2.05%, 1.49%, and 1.28%, respectively.

CONCLUSIONS

Fasting blood glucose level is a superior predictor of mortality risk and may be used as a simple predictive and preventative factor.

Characteristics of insulin resistance in Korean adults from the perspective of circadian and metabolic sensing genes

BACKGROUND

The biological clock allows an organism to anticipate periodic environmental changes and adjust its physiology and behavior accordingly.

OBJECTIVE

This retrospective cross-sectional study examined circadian gene polymorphisms and clinical characteristics associated with insulin resistance (IR).

METHODS

We analyzed data from 1,404 Korean adults aged 30 to 55 with no history of cancer and cardio-cerebrovascular disease. The population was classified according to sex and homeostasis model assessment of insulin resistance (HOMA-IR) values. Demographics, anthropometric and clinical characteristics, and single nucleotide polymorphisms (SNPs) were analyzed with respect to sex, age, and HOMA-IR values. We used association rule mining to identify sets of SNPs from circadian and metabolic sensing genes that may be associated with IR.

RESULTS

Among the subjects, 15.0% of 960 women and 24.3% of 444 men had HOMA-IR values above 2. Most of the parameters differed significantly between men and women, as well as between the groups with high and low insulin sensitivity. Body fat mass of the trunk, which was significantly higher in insulin-resistant groups, had a higher correlation with high sensitivity C-reactive protein and hemoglobin levels in women, and alanine aminotransferase and aspartate aminotransferase levels in men. Homozygous minor allele genotype sets of SNPs rs17031578 and rs228669 in the PER3 gene could be more frequently found among women with HOMA-IR values above 2 (p = .014).

CONCLUSION

Oxidative stress enhanced by adiposity and iron overload, which may also be linked to NRF2 and PER3-related pathways, is related to IR in adulthood. However, due to the small population size in this study, more research is needed.

Association of nut consumption with insulin resistance and blood lipid profile in Spanish university students

AIMS

To examine whether nut consumption was associated with insulin resistance and blood lipid parameters in a sample of young healthy adults.

MATERIAL AND METHODS

A cross-sectional study was conducted involving 306 first-year students (aged 18-30 years) from the University of Castilla-La Mancha, Spain. Biochemical variables related to insulin resistance and blood lipid profile (glucose, insulin, HbA1c, total cholesterol (total-c), LDL-c, HDL-c, and triglycerides) were determined from morning fasting blood samples. Nut consumption was estimated using a 137-item Food-Frequency Questionnaire. The associations of walnuts, other nuts and total nut intakes with insulin resistance and lipid profile variables and surrogates were assessed by linear regression analysis. Differences in insulin resistance and lipid profiles between participants meeting or not meeting the nut consumption recommendations were examined by analysis of covariance (ANCOVA). Logistic regressions were used to analyze the likelihood of having higher levels of blood lipids or insulin resistance in participants who met or did not meet the recommended intake of nuts.

RESULTS

There was no association found between nut consumption, whether walnuts or other nut varieties, and insulin resistance and lipid profile variables. Additionally, there were no significant differences in insulin resistance or blood lipid profile variables between university students meeting or not meeting nut consumption recommendations. Finally, stratified analyses based on sex were consistent and did not substantially modify our estimates in the fully adjusted models.

CONCLUSIONS

In conclusion, our results suggest that walnuts, other types of nuts, and total nut consumption did not adversely influence metabolic or lipid profile variables among healthy young adults. Although nuts are recommended among healthy dietary patterns, our findings showed that nut consumption has a null effect on the cardiometabolic risk parameters explored in young healthy adults.

Inverse association of daily fermented soybean paste (“Jang”) intake with metabolic syndrome risk, especially body fat and hypertension, in men of a large hospital-based cohort

Introduction

Jang is a fermented soybean paste containing salt and is traditionally used as a substitute for salt to enhance the flavor of foods in Korea. It has been speculated that regular consumption of Jang may lower the risk of metabolic syndrome (MetS). We hypothesized that Jang intake was associated with the risk of MetS and its components after adjusting for potential confounders, including sodium intake. The hypothesis was investigated according to gender in a large city hospital-based cohort (n = 58,701) in Korea.

Methods

Jang intake, calculated as the sum of the intakes of Chungkookjang, Doenjang, Doenjang soup, and Ssamjang (a mixture of Doenjang and Kochujang), was included in the semi-quantitative food frequency questionnaire (SQFFQ) administered to the cohort, and the daily Jang intake was estimated. The participants were categorized into low-Jang and high-Jang groups by 1.9 g daily Jang intake. MetS was defined according to 2005 revised United States National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria modified for Asians.

Results

The participants in the low-Jang and high-Jang groups consumed an average of 0.63 g and 4.63 g Jang daily; their total sodium intake was about 1.91 and 2.58 g/day, respectively. The participants in the high-Jang group had higher energy, fiber, calcium, vitamin C, vitamin D, and potassium intake than those in the low-Jang group. After adjusting for covariates, the participants with the highest sodium intake (≥3.31 g/day) were positively associated with MetS risk in the quintiles of men and women. Among the MetS components, waist circumference, fat mass, and hypo-high-density lipoprotein (HDL)-cholesterolemia were positively associated with sodium intake in all participants and women. Unlike the association seen with sodium intake, Jang intake (≥1.9 g/day) was inversely associated with MetS components, including waist circumference, fat mass, serum glucose concentrations, and hypo-HDL-cholesterolemia in all participants and men, after adjusting for covariates including sodium intake.

Discussion

Substituting salt for Jang in cooking may be recommended to prevent and alleviate MetS incidence, and its efficacy for MetS risk was better in men than women. The results can be applied to sodium intake in Asian countries where salt is used to promote flavor.

Association of lipid accumulation product with type 2 diabetes mellitus, hypertension, and mortality: a systematic review and meta-analysis

Purpose

Novel anthropometric measures are simple, applicable, and inexpensive tools for cardiovascular risk assessment. This study evaluates the association of lipid accumulation product (LAP) with hypertension, type 2 diabetes mellitus (T2DM), and all-cause mortality, and compares it with other anthropometric measures.

Methods

PubMed, Web of Science, EMBASE, and Scopus were systematically searched for articles published until May 15, 2021. We included all the studies that had measured LAP predictability for T2DM, all-cause mortality, and hypertension with no limitation in comorbidities and follow-up duration. We assessed the predictability measures of LAP for the aforementioned outcomes. We also performed a meta-analysis on four articles on mortality using an inverse variance method by the "meta" package in R software.

Results

Twenty-nine studies were included in the review after applying the eligibility criteria. The hazard ratio for all-cause mortality per one standard deviation increment of LAP was 1.24 (95% confidence interval [CI]: 1.00-1.53; P = 0.0463) in females, and 1.07 (95% CI: 0.74-1.57; P = 0.709) in males. All included studies found a direct association between LAP with T2DM and hypertension. However, studies used different cut-off points for LAP. Most studies found that LAP was superior in predicting T2DM and hypertension compared to conventional indices, e.g., body mass index and waist circumference. We found that LAP may have higher prognostic significance in females compared to males.

Conclusion

LAP is an inexpensive method to evaluate the risk of all-cause mortality, T2DM, and hypertension, and could outperform conventional anthropometric indices in this regard.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01114-z.

Inverse association of a traditional Korean diet composed of a multigrain rice-containing meal with fruits and nuts with metabolic syndrome risk: The KoGES

Background

Hansik, a traditional Korean diet, may have a beneficial impact on metabolic syndrome (MetS) risk as dietary westernization increases its prevalence. We examined the hypothesis that adherence to the hansik diet may be inversely associated with the risk of MetS and its components and sought to understand the gender differences in 58,701 men and women aged over 40.

Materials and methods

Hansik was defined using 14 components from which the Korean dietary pattern index (K_diet-index) was generated by summing their scores. Low-hansik intake was defined as the K_diet-index with <8. MetS was categorized based on the 2005 revised NCEP-ATP III criteria modified for Asians.

Results

The K_diet-index score was negatively associated with the dietary inflammation index and showed that the high intake of a meal with multigrain rice, fruits, and their products, and nuts, and low intake of fried foods were inversely associated with MetS by 0.707, 0.864, 0.769, and 0.918 times, respectively, after adjusting for covariates. More women and participants with more educated and lower income belonged to the high-hansik group, and participants with high self-rated health scores consumed more hansik. All participants on a high-hansik diet were associated with a 0.87 time lower risk of MetS. Specifically, the association between hansik intake and MetS risk was not significant among men following stratification by gender. Body composition, including the body mass index, waist circumference, and fat mass, was inversely associated with hansik intake, while the skeletal muscle mass index was positively associated with the hansik intake in each gender and all participants. In all the participants in the high-hansik group, no significant changes were seen in the serum glucose and HDL concentration. However, a high-hansik intake showed lower blood pressure and serum LDL and triglyceride concentrations only in men and a higher glomerular filtration rate in both genders.

Conclusions

Hansik intake might improve MetS risk, with its primary beneficial effects on body composition, dyslipidemia, and blood pressure gender-dependently.

Association between the triglyceride-glucose (TyG) index and increased blood pressure in normotensive subjects: a population-based study

BACKGROUND

Insulin resistance (IR) is an important contributor to the development of hypertension (HTN), and the triglyceride-glucose (TyG) index has been proposed as a simple, reliable marker of IR. This study investigated the association between the TyG index and blood pressure (BP) elevation in a large general population.

METHODS

The study enrolled 15,721 adults with no history of cardiometabolic diseases from the 2016-2019 Korea National Health and Nutrition Examination Survey. Participants were classified into quartiles based on the TyG index and BP was categorized as normal BP, elevated BP, pre-HTN, and HTN. The associations of the TyG index with BP categories were assessed using multivariate multinomial logistic regression models with normal BP as the reference group.

RESULTS

The mean systolic/diastolic BP and prevalence of HTN increased with the TyG index (P for trend < 0.001). The continuous TyG index had a strong dose-response relationship with increased odds of elevated BP, pre-HTN, and HTN. Compared with the lowest TyG index quartile, the highest TyG index quartile was significantly associated with higher odds of having elevated BP (odds ratio [OR], 1.52; 95% confidence interval [CI], 1.24-1.87; P for trend < 0.001), pre-HTN (OR, 2.22; 95% CI, 1.95-2.53; P for trend < 0.001), and HTN (OR, 4.24; 95% CI, 3.49-5.16; P for trend < 0.001).

CONCLUSION

We found that a higher TyG index was positively associated with the risk of increased BP in normal healthy individuals. This study suggests that the TyG index might serve as a potential predictor of HTN. However, further studies with larger sample sizes and various target populations in longitudinal designs are needed.

Insulin Resistance Markers to Detect Nonalcoholic Fatty Liver Disease in a Male Hispanic Population

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease and is closely associated with cardiometabolic disorders, being insulin resistance (IR) the common pathogenic mechanism. The triglycerides/glucose (TyG) index and triglycerides/HDL-c (TG/HDL) ratio are markers correlated with IR. We compared the capacity of these two indexes, alongside IR, to detect NAFLD.

METHODS

In a cross-sectional cohort study, we examined 263 active military personnel from the Colombian Air Force, aged between 29 and 54 years. Anthropometric measurements and biochemical determinations (glycemia, lipid profile, and insulin) were obtained, and ultrasound studies were performed to evaluate the presence of NAFLD. HOMA-IR index was calculated as (fasting insulin (µIU/mL) × fasting glucose (mmol/L)/22.5), the TyG index as Ln (triglycerides (mg/dL) × fasting glucose (mg/dL)/2), and the TG/HDL ratio as (triglycerides (mg/dL)/HDL-c (mg/dL)).

RESULTS

NAFLD ultrasound criteria were met in 70 individuals (26.6%). Subjects with NAFLD had significantly higher values of HOMA-IR (2.55 ± 1.36 vs. 1.51 ± 0.91), TyG (9.17 ± 0.53 vs. 8.7 ± 0.51), and TG/HDL (6.6 ± 4.54 vs. 3.52 ± 2.32) compared to those without NAFLD (p < 0.001). A TyG cutoff point of 8.92 showed an AUC of 0.731, while cutoff points of 3.83 for TG/HDL and 1.68 for HOMA-IR showed an AUC of 0.766 and 0.781, respectively.

CONCLUSION

Our study shows that novel and lower-cost markers of IR are useful for detecting NALFD, with a performance comparable to the HOMA-IR index. These markers should be used as the first step when screening patients for NAFLD.

Challenges in the diagnosis of insulin resistance: Focusing on the role of HOMA-IR and Tryglyceride/glucose index

BACKGROUND AND AIMS

Metabolic Syndrome (MS) prevalence is increasing worldwide in line with the growing prevalence of obesity. The underlying mechanism of MS is insulin resistance which can be diagnosed by measuring Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Triglyceride/Glucose (TyG) Index. This review will focus on comparing studies assessing the HOMA-IR and TyG index cut-off points.

METHODS

We carried out a comprehensive review of the literature using suitable keywords on the search engines of PubMed, Scopus, Research Gate, and Google Scholar in the month of October 2020.

RESULTS

There is a high degree of variability in determining threshold levels of HOMA-IR for defining insulin resistance. The distribution of the HOMA-IR varies according to the demographic characteristics of the subjects, such as age, sex, and race, making it difficult to estimate the optimal cut-off point. Another simpler method without requiring the use of insulin assays is TyG Index. Similar to HOMA-IR, the TyG Index cut-off point from existing data shows varying results.

CONCLUSION

The HOMA-IR and the TyG index are simple and widely used methods for determining insulin resistance. However, an issue that arises is determining the insulin resistance cut-off point for both methods. Further studies are needed to assess the cut-off point of insulin resistance for various ethnicities associated with the risk of developing MS later in life.

Impact of metabolic syndrome and metabolic dysfunction-associated fatty liver disease on cardiovascular risk by the presence or absence of type 2 diabetes and according to sex

Background

To determine the impact of metabolic syndrome (MetS) and/or metabolic dysfunction-associated fatty liver disease (MAFLD), which are pathophysiologically similar and include insulin resistance, on the development of new-onset cardiovascular disease with and without type 2 diabetes and according to sex.

Methods

This study included 570,426 individuals without a history of cardiovascular disease who were enrolled in a nationwide claims database from 2008 to 2016 and were classified by the presence or absence of MetS and/or MAFLD stratified by the presence or absence of type 2 diabetes and sex. The fatty liver index was used to determine the presence or absence of fatty liver that required a diagnosis of MAFLD. Risks of developing coronary artery disease (CAD) and cerebrovascular disease (CVD) in each category were analyzed using a multivariate Cox proportional hazard model.

Results

During a median follow-up of 5.2 years, 2252 CAD and 3128 CVD events occurred. Without type 2 diabetes the hazard ratio (HR) (95% CI) for CAD/CVD compared with neither MAFLD nor MetS was 1.32 (1.17–1.50)/1.41(1.28–1.57) for MAFLD only (without MetS), 1.78 (1.22–2.58)/1.66 (1.34–2.06) for MetS only (without MAFLD), and 2.10 (1.84–2.39)/1.73 (1.54–1.95) for MAFLD + MetS. For those with type 2 diabetes, the HR for CAD for MAFLD only (compared with neither MAFLD nor MetS) was 1.29 (1.06–1.58), for MetS only 1.34 (0.84–2.13), and for MAFLD + MetS 1.22 (1.02–1.47). For CVD, there was a significant increase in HR only in MAFLD + MetS [1.44 (1.18–1.76)]. The results of the analysis stratified by sex showed that MAFLD had a greater impact in men, and MetS had a greater impact in women regarding the development of CAD.

Conclusions

Distinguishing between MetS and/or MAFLD in the presence or absence of type 2 diabetes and according to sex may aid in accurately identifying patients at high risk of cardiovascular disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01518-4.

Association Between Smoking Behavior and Insulin Resistance Using Triglyceride-Glucose Index Among South Korean Adults

CONTEXT

Insulin resistance is a determinant of diabetes. With the increasing popularity of electronic smoking, the number of dual smokers (smoking both cigarettes and electronic cigarettes [e-cigarettes]) is increasing. However, few studies have assessed the association between insulin resistance and smoking behavior, including dual smoking.

OBJECTIVE

This work aims to investigate the association between smoking behaviors and insulin resistance.

METHODS

This prospective, cross-sectional study took place among the general community. A total of 11 653 participants (4721 male and 6932 female) aged 19 years or older from the 2016 to 2018 Korea National Health and Nutrition Examination Survey were divided based on their smoking behaviors: dual smokers (both cigarettes and e-cigarettes), single smokers (cigarette smokers), previous smokers, and nonsmokers. Insulin resistance was determined based on the triglyceride-glucose index. Multiple logistic regression analysis was performed to investigate the association between smoking behavior and insulin resistance.

RESULTS

Among the participants, 205 males (3.9%) and 40 females (0.5%) were dual smokers, and 1581 males (29.9%) and 350 females (4.5%) were single smokers. Male and female smokers (dual and single) both had higher odds of being in a group with higher insulin resistance than nonsmokers (male, dual: OR = 2.19; 95% CI, 1.39-3.44; single: OR = 1.78; 95% CI, 1.43-2.22; female, dual: OR = 2.32; 95% CI, 1.01-5.34; single: OR = 1.76; 95% CI, 1.28-2.42).

CONCLUSION

This study suggests that single and dual smoking both may increase the risk of insulin resistance in the general population. Education on the adverse effects of smoking behaviors may be an important strategy to improve the health of the population.

Lipid Accumulation Product Is More Related to Insulin Resistance than the Visceral Adiposity Index in the Maracaibo City Population, Venezuela

BACKGROUND

Visceral adiposity is related to insulin resistance (IR), a metabolic state considered as a risk factor for other cardiometabolic diseases. In that matter, mathematical indexes such as the visceral adiposity index (VAI) and the lipid accumulation product (LAP) could indirectly assess IR based on visceral adiposity.

OBJECTIVE

To evaluate the association and diagnostic accuracy of VAI and LAP to diagnose IR in the adult population of Maracaibo city.

METHODS

This is a cross-sectional descriptive study with multistage sampling. Receiver operating characteristic (ROC) curves were built to determine VAI and LAP cutoff points to predict IR. A set of logistic regression models was constructed according to sociodemographic, psychobiologic, and metabolic variables.

RESULTS

1818 subjects were evaluated (51.4% women). The area under the curve (AUC) values for LAP and VAI were 0.689 (0.665-0.714) and 0.645 (0.619-0.670), respectively. Both indexes showed a higher IR risk in the upper tertile in bivariate analysis. However, in the logistic regression analysis for the IR risk, only the 2nd (OR: 1.91; 95% CI: 1.37-2.65; p < 0.01) and 3rd (OR: 5.40; 95% CI: 3.48-8.39; p < 0.01) LAP tertiles showed a significant increase. This behaviour was also observed after adjusting for hs-C-reactive protein (hs-CPR).

CONCLUSION

Although both indexes show a low predictive capacity in individuals with IR in the Maracaibo city population, the LAP index was more strongly associated with IR.

Brief Report: Improvement in Metabolic Health Parameters at Week 48 After Switching From a Tenofovir Alafenamide-Based 3- or 4-Drug Regimen to the 2-Drug Regimen of Dolutegravir/Lamivudine: The TANGO Study

BACKGROUND

In TANGO, switching to dolutegravir/lamivudine was noninferior at 48 weeks to continuing 3-/4-drug tenofovir alafenamide-based regimens in virologically suppressed individuals with HIV-1. Antiretroviral agents have been associated with weight gain and metabolic complications.

SETTING

One hundred thirty-four centers; 10 countries.

METHODS

We assessed weight; fasting lipids, glucose, and insulin; and prevalence of insulin resistance and metabolic syndrome at baseline and week 48 in TANGO participant subgroups by boosting agent use in baseline regimens (boosted and unboosted).

RESULTS

In each treatment group, 74% of participants used boosted regimens at baseline. In boosted and unboosted subgroups, weight and fasting glucose changes at week 48 were small and similar between treatment groups. Overall and in the boosted subgroup, greater decreases from baseline were observed with dolutegravir/lamivudine in fasting total cholesterol (P < 0.001), low-density lipoprotein cholesterol (P < 0.001), triglycerides (P < 0.001), total cholesterol/high-density lipoprotein cholesterol ratio (overall, P = 0.017; boosted, P = 0.007), and insulin (boosted, P = 0.005). Prevalence of HOMA-IR ≥2 was significantly lower at week 48 with dolutegravir/lamivudine overall [adjusted odds ratio (aOR), 0.59; 95% confidence interval (CI), 0.40 to 0.87; P = 0.008] and in the boosted subgroup [aOR, 0.56; 95% CI, 0.36 to 0.88; P = 0.012] but not in the unboosted subgroup [aOR, 0.70; 95% CI, 0.31 to 1.58; P = 0.396]. Prevalence of metabolic syndrome at week 48 was low and consistent between treatment groups overall, with differences trending to favor dolutegravir/lamivudine in the unboosted subgroup [aOR, 0.41; 95% CI, 0.15 to 1.09; P = 0.075].

CONCLUSION

Generally, switching from 3-/4-drug tenofovir alafenamide-based regimens to dolutegravir/lamivudine improved metabolic parameters, particularly when switching from boosted regimens. Because of smaller sample size in the unboosted subgroup, results warrant further investigation.

Evaluation of Plasma AA/DHA+EPA Ratio in Obese Romanian Children

The aim of the study was to evaluate the plasma profile of arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), as well to analyze the relationship of Omega 6/Omega 3 ratio with anthropo-metric parameters and insulin resistance markers.

Material and methods: Plasma levels of free fatty acids (FFAs) were measured using a high-throughput LC-MS AB Sciex4600 in 202 children (127 obese and 75 non-obese), age and sex-matched. Lipid and glucose profiles were assessed with current laboratory methods, while insulin resistance and beta-cell function were evaluated using HOMA-IR and HOMA-β respectively.

Results: In obese children, AA and AA/(DHA+EPA) ratio were significantly higher regardless of age and gender. In the lowest quartile of DHA, there was a clear trend for insulin resistance, with plasma insulin level, HOMA-IR, and HOMA-β significantly higher compared to the highest quartile of DHA. After adjustment for age and gender DHA remains a negative predictive factor for insulin resistance. Waist-to-height ratio (WHtR), a marker of visceral obesity was higher in children with a higher AA/(DHA+EPA) ratio.

Conclusions: In obese children, the AA is higher in concordance with insulin resistance. Additionally, children with a higher AA/(DHA+EPA) ratio have greater BMI, fat mass, waist circumference, and WHtR, important indicators of central adiposity, and cardio-metabolic disorders. LC/MS is a versatile tool for Omega ratio assessment, especially in children where the sample size is a limiting factor for metabolic and nutrition evaluation.

Association between insulin resistance and lung function trajectory over 4 years in South Korea: community-based prospective cohort

Background

Hyperglycemic conditions are associated with respiratory dysfunction. Although several studies have reported that insulin resistance (IR) is related to decreased lung function, the association between IR and change in lung function has been rarely studied. This study aimed to investigate the potential association of IR on annual change in lung function using a community-based prospective cohort in Korea.

Methods

We selected 4827 Korean participants whose serial lung functions were assessed over 4 years using 1:3 propensity score matching. Exposure was baseline IR estimated with homeostatic model assessment (HOMA-IR), and outcomes were annual changes in lung function determined by calculating the regression coefficient using least-square linear regression analysis.

Results

In the multivariate linear regression, per one unit increased log transformed HOMA-IR was associated with decline in FEV₁%-predicted (β: − 0.23, 95% CI: − 0.36 to − 0.11) and FVC %-predicted (β: − 0.20, 95% CI: − 0.33 to − 0.08), respectively. In the generalized additive model plot, HOMA-IR showed a negative linear association with annual changes in FEV₁%-predicted and FVC %-predicted. The suggested threshold of HOMA-IR for decline in lung function was 1.0 unit for annual change in FEV₁%-predicted and 2.2 unit for annual change in FVC %-predicted. Age showed statistically significant effect modification on the relationship between HOMA-IR and annual change in FEV₁%-predicted. Increased HOMA-IR was associated with the decreased annual change in FEV₁%-predicted, particularly in older people.

Conclusions

In South Korea, increased HOMA-IR was associated with decline in lung function. Since IR was related to decline in FEV₁%-predicted, particularly in older people, tailored approaches are needed in these populations. The potential pulmonary hazard of IR needs to be confirmed in future studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01478-7.

Body Fat Indices as Effective Predictors of Insulin Resistance in Obstructive Sleep Apnea: Evidence from a Cross-Sectional and Longitudinal Study : BFI as Predictors of IR in OSA

PURPOSE

Body fat indices serve as predictive markers of insulin resistance (IR) in metabolic diseases. IR is common in obstructive sleep apnea (OSA). However, whether body fat indices have utility as predictors of IR in OSA remain unknown.

MATERIALS AND METHODS

A longitudinal study was conducted in 46 patients undergoing bariatric surgery to explore the relationship between IR and body fat indices. Then, a cross-sectional study was performed to evaluate the relationships between body fat indices and IR, and receiver operating characteristic (ROC) curves were generated. Body indices, homeostasis model assessment index of insulin resistance (HOMA-IR), biological indicators, and polysomnographic variables were collected.

RESULTS

In the longitudinal study, significant relationships were found between remission of IR and changes in visceral adiposity index (VAI) (r = 0.452, P < 0.05) and triglyceride-glucose index (TyG) (r = 0.650, P < 0.01). In the cross-sectional study, lipid accumulation product (LAP) (best cutoff value: 30.16, area under the curve (AUC) = 0.728, P < 0.001) and TyG (best cutoff value: 8.54, AUC = 0.740, P < 0.001) were indicators of IR in normal weight group. In overweight/obese group, body mass index (BMI) (best cutoff value: 27.69 AUC = 0.707, P < 0.001) and waist circumference (WC) (best cutoff value: 97.25, AUC = 0.708, P < 0.001) were markers of IR. TyG showed better ability to predict IR in normal weight females (best cutoff value: 8.39 AUC = 0.813, P < 0.001).

CONCLUSIONS

Body fat indices are predictive markers of IR in patients with OSA.

Lipid indices as simple and clinically useful surrogate markers for insulin resistance in the U.S. population

This study aimed to compare the accuracy of novel lipid indices, including the visceral adiposity index (VAI), lipid accumulation product (LAP), triglycerides and glucose (TyG) index, TyG-body mass index (TyG-BMI), and TyG-waist circumference (TyG-WC), in identifying insulin resistance and establish valid cutoff values. This cross-sectional study used the data of 11,378 adults, derived from the United States National Health and Nutrition Examination Survey (1999-2016). Insulin resistance was defined as a homeostasis model assessment-insulin resistance value above the 75th percentile for each sex and race/ethnicities. The area under the curves (AUCs) were as follows: VAI, 0.735; LAP, 0.796; TyG index, 0.723; TyG-BMI, 0.823, and; TyG-WC, 0.822. The AUCs for TyG-BMI and TyG-WC were significantly higher than those for VAI, LAP, and TyG index (vs. TyG-BMI, p < 0.001; vs. TyG-WC, p < 0.001). The cutoff values were as follows: VAI: men 1.65, women 1.65; LAP: men 42.5, women 42.5; TyG index: men 4.665, women 4.575; TyG-BMI: men 135.5, women 135.5; and TyG-WC: men 461.5, women 440.5. Given that lipid indices can be easily calculated with routine laboratory tests, these values may be useful markers for insulin resistance risk assessments in clinical settings.

Triglyceride-glucose index predicts independently type 2 diabetes mellitus risk: A systematic review and meta-analysis of cohort studies

OBJECTIVE

Our objective was to perform a systematic review and meta-analysis of cohort studies evaluating the triglyceride-glucose (TyG) index as a tool for type 2 diabetes (T2D) prediction in adults and older adults.

METHODS

Studies were identified in PubMed, Cochrane, Scopus, and Lilacs. Studies with cohort design, which evaluated the T2D incidence through the hazard ratio (HR) or relative risk (RR) or odds ratio values were included. Were included both studies that evaluated the incidence of T2D from tertiles, quartiles, quintiles, or single TyG index values. First, a meta-analysis only for studies that reported data in HR values was performed. Additionally, given the different association measurements used, the number of T2D cases, non-T2D cases, and the total number of participants were extracted from exposed and non-exposed groups when available. Then the risk ratio was calculated. A meta-analysis using the inverse variance method and the random-effects model was performed. Heterogeneity was assessed by I² statistics and by inspecting funnel plots.

RESULTS

Thirteen cohort studies with a total of 70,380 subjects, both sexes, adults, and older adults were included in the meta-analysis. Ten studies showed a significant association of the TyG index with T2D risk through HR estimative (overall HR: 2.44, 95% CI: 2.17-2.76). After estimating RR for nine studies, we also observed a significant association of the TyG index with T2D risk (RR: 3.12, 95 CI: 2.31-4.21). For all analyses, high heterogeneity was verified by I² and visual inspection of funnel plots.

CONCLUSIONS

TyG index has a positive and significant association with T2D risk, suggesting that the TyG index may become an applicable tool to identify subjects with T2D risk. However, due to the high heterogeneity observed in overall HR and RR analysis, more studies could be necessary to confirm these results.

Elevated serum levels of galectin-3 binding protein are associated with insulin resistance in non-diabetic women after menopause

OBJECTIVE

Galectin-3 binding protein (Gal-3BP) is one of the major fucosylated glycoprotein family members and has recently been implicated in non-alcoholic fatty liver disease, hyperlipaemia and coronary artery disease. Here, we analysed the serum concentrations of Gal-3BP in menopausal women to evaluate the association of circulating Gal-3BP and insulin resistance in females after menopause.

MATERIALS AND METHODS

We evaluated serum levels of Gal-3BP in sixty-two non-diabetic women with menopausal status for at least one year. The clinical features, biochemical profiles and homeostasis model assessment of insulin resistance (HOMA-IR) indices were obtained routinely.

RESULTS

Gal-3BP levels increased in women with higher HOMA-IR indices and were positively correlated with HOMA-IR indices. The Gal-3BP level was also an independent risk factor for a high HOMA-IR index and showed the most influence on the HOMA-IR index compared to fasting plasma glucose, triglyceride, age and body mass index. The cut-off value of the serum Gal-3BP level was 2234.32 ng/ml, with areas under the ROC curve (AUCs) of 0.68 (HOMA-IR index 1.5), 0.81 (HOMA-IR index 2.0) and 0.93 (HOMA-IR index 2.5).

CONCLUSION

Serum levels of Gal-3BP are associated with impaired insulin sensitivity in non-diabetic menopausal women.

Association of grip strength with non-alcoholic fatty liver disease: investigation of the roles of insulin resistance and inflammation as mediators

BACKGROUND/OBJECTIVES

The purpose of this study was to examine the association between muscle weakness and non-alcoholic fatty liver disease (NAFLD), and whether the association is partly explained by insulin resistance or inflammation.

SUBJECTS/METHODS

Subjects were 3922 adults who participated in the 2015 Korea National Health and Nutrition Examination Survey. Relative grip strength (rGS; calculated as maximal grip strength divided by BMI) was used to predict NAFLD defined by NAFLD liver fat score. Participants were classified into four groups according to the quartiles of rGS distribution (Q1-Q4). Insulin resistance was assessed by triglycerides and glucose (TyG) index. Inflammation was measured with C-reactive protein (CRP). Fibrosis was assessed by the Fibrosis-4 index (FIB-4) and the NAFLD fibrosis score.

RESULTS

rGS had significant negative associations with TyG index and CRP (all p < 0.001). rGS was a significant predictor of NAFLD (OR, 0.54-0.19 in Q2-Q4 men; OR, 0.54-0.08 in Q2-Q4 women, all p < 0.001). Adjustment for other participant factors did not substantially affect the results. Addition of TyG index changed the estimates for NAFLD slightly and addition of CRP increased the ORs by 10-20% in Q3-Q4 women. In the subpopulation with NAFLD (n = 946), rGS showed strong inverse relationships with FIB-4 and NAFLD fibrosis score (all p < 0.001).

CONCLUSIONS

Grip strength was inversely associated not only with the risk of NAFLD but also with its severity. Insulin resistance and inflammation explained only a small portion of the association between grip strength and NAFLD risk.

The effect of anti-TNF treatment on body composition and insulin resistance in patients with rheumatoid arthritis

Given the link between systemic inflammation, body composition and insulin resistance (IR), anti-inflammatory therapy may improve IR and body composition in inflammatory joint diseases. This study assesses the IR and beta cell function in rheumatoid arthritis (RA) patients with active disease compared to osteoarthritis (OA) patients and investigates the effect of anti-TNF treatment on IR, beta cell function and body composition in RA. 28 Consecutive RA patients starting anti-TNF treatment (adalimumab), and 28 age, and sex-matched patients with OA were followed for 6 months. Exclusion criteria were use of statins, corticosteroids, and cardiovascular or endocrine co-morbidity. Pancreatic beta cell function and IR, using the homeostasis model assessment (HOMA2), and body composition, using dual-energy X-ray absorptiometry (DXA) were measured at baseline and 6 months. At baseline, IR [1.5 (1.1–1.8) vs. 0.7 (0.6–0.9), 100/%S] and beta cell function (133% vs. 102%) were significantly (p < 0.05) higher in RA patients with active disease as compared to OA patients. After 6 months of anti-TNF treatment, IR [1.5 (1.1–1.8) to 1.4 (1.1–1.7), p = 0.17] slightly improved and beta cell function [133% (115–151) to 118% (109–130), p <0.05] significantly improved. Improvement in IR and beta cell function was most pronounced in RA patients with highest decrease in CRP and ESR. Our observations indicate that IR and increased beta cell function are more common in RA patients with active disease. Anti-TNF reduced IR and beta cell function especially in RA patients with highest decrease in systemic inflammation and this effect was not explained by changes in body composition.

Genetically, Dietary Sodium Intake Is Causally Associated with Salt-Sensitive Hypertension Risk in a Community-Based Cohort Study: a Mendelian Randomization Approach

PURPOSE OF REVIEW

Excessive dietary salt intake is associated with an increased risk of hypertension. Salt sensitivity, i.e., an elevation in blood pressure in response to high dietary salt intake, has been associated with a high risk of cardiovascular disease and mortality. We investigated whether a causal association exists between dietary sodium intake and hypertension risk using Mendelian randomization (MR).

RECENT FINDINGS

We performed an MR study using data from a large genome-wide association study comprising 15,034 Korean adults in a community-based cohort study. A total of 1282 candidate single nucleotide polymorphisms associated with dietary sodium intake, such as rs2960306, rs4343, and rs1937671, were selected as instrumental variables. The inverse variance weighted method was used to assess the evidence for causality. Higher dietary sodium intake was associated with salt-sensitive hypertension risk. The variants of SLC8E1 rs2241543 and ADD1 rs16843589 were strongly associated with increased blood pressure. In the logistic regression model, after adjusting for age, gender, smoking, drinking, exercise, and body mass index, the GRK4 rs2960306TT genotype was inversely associated with hypertension risk (OR, 0.356; 95% CI, 0.236-0.476). However, the 2350GG genotype (ACE rs4343) exhibited a 2.11-fold increased hypertension risk (OR, 2.114; 95% CI, 2.004-2.224) relative to carriers of the 2350AA genotype, after adjusting for confounders. MR analysis revealed that the odds ratio for hypertension per 1 mg/day increment of dietary sodium intake was 2.24 in participants with the PRKG1 rs12414562 AA genotype. Our findings suggest that dietary sodium intake may be causally associated with hypertension risk.

Association between Frequency of Breakfast Consumption and Insulin Resistance Using Triglyceride-Glucose Index: A Cross-Sectional Study of the Korea National Health and Nutrition Examination Survey (2016-2018)

Diabetes mellitus is an important chronic disease causing economic and social burden. Insulin resistance is a determinant of diabetes, and regular eating patterns are an important factor in blood sugar control. This study investigated the association between breakfast frequency and the risk of increased insulin resistance in Koreans. Data for 12,856 participants without diabetes in the 2016–2018 Korea National Health and Nutrition Examination Survey were analyzed. Insulin resistance was assessed using the triglyceride-glucose (TyG) index, while the median TyG index value was used to define higher (≥8.5) vs. lower (<8.5) insulin resistance. Association between breakfast frequency and risk of increased insulin resistance was investigated using multiple logistic regression. Compared with those who had regular breakfast 5–7 times per week, the odds ratios (95% confidence intervals) of individuals who did not eat breakfast were the highest at 1.42 (95% CI = 1.24–1.64, p ≤ 0.0001). Those who had breakfast 1–4 times per week had an odds ratio of 1.17 (95% CI = 1.03–1.32, p = 0.0153). We found that a lower weekly breakfast consumption was associated with a higher risk of insulin resistance in Koreans. Promoting the benefits of breakfast can be an important message to improve the health of the population.

Association between serotonin 2A receptor (HTR2A) genetic variations and risk of hypertension in a community-based cohort study

Background

Hypertension is one of the risk factors for obesity-related cardiovascular diseases. We investigated whether genetic variations in serotonin 2A receptor (HTR2A) were associated with hypertension.

Methods

We carried out a cross-sectional study in cohorts A (Ansan-Ansung cohort, N = 6039) and B (Wonju-Pyengchang cohort, N = 7524). Several genetic variants in HTR2A including rs7330636, rs9590999, rs2183057, and rs4942595 were selected and genotyped.

Results

In hypertensive participants in cohort A, the baseline systolic blood pressure and body mass index were 141.80 ± 17.20 mg/dL and 24.48 ± 4.75 kg/m², respectively, which were higher than in those without hypertension (p < 0.001). rs4942595TC genotype was associated with hypertension in cohort A (OR = 0.739), after adjusting for variables. Subjects with rs4942578AA genotype had a decreased risk of hypertension after adjusting for clinical factor (OR = 0.735) in cohort B, and an elevated risk of hypertension in cohort A (OR = 1.562). The logistic regression analysis showed that participants with rs4941573TC genotype were 1.327 times more likely to have a higher blood pressure than those with TT genotype (95% CI 1.101–1.599) in cohort B. Whereas, the OR for developing hypertension in subjects with rs17069883CC genotype compared to those with AA genotype was 1.447 (95% CI 1.018–2.056; p for trend = 0.040) in cohort A.

Conclusions

HTR2A genetic variations were associated with hypertension risk in our study.

A longitudinal epidemiological study on the triglyceride and glucose index and the incident nonalcoholic fatty liver disease

BACKGROUND

Triglyceride and glucose (TyG) index and nonalcoholic fatty liver disease (NAFLD) both bave been related to insulin resistance (IR). The study aimed to investigate the longitudinal relationship between TyG index and NAFLD and to evaluate the ability of TyG, through comparing with the predictive value of other indexes, to identify individuals at risk for NAFLD.

METHODS

Four thousand and five hundred thirty nine subjects without NAFLD initially were followed up for 9 years. Cox regression models were used to analyze the risk factors of NAFLD.

RESULTS

Cox regression analyses indicated the TyG index was independently and positively associated with the risk of incident NAFLD. In receiver operating characteristic (ROC) curve analysis, the optimal cut-off level for TyG to predict incident NAFLD was 8.52 and the area under the ROC curve (AUC) was 0.76 (95% CI 0.74-0.77), which was larger than that of TG, ALT and FPG.

CONCLUSION

This study demonstrated that the elevation of the TyG index might predict increase risk for incident NAFLD and it may be suitable as a diagnostic criterion for NAFLD.