Insulin resistance: definition and consequences

Associations between triglyceride glucose index-related obesity indices and anxiety: Insights from the National Health and Nutrition Examination Survey 2007-2012

BACKGROUND

The triglyceride glucose index (TyG), along with its associated obesity indices, including TyG-body mass index (TyG-BMI), TyG-waist-to-height ratio (TyG-WHtR), TyG-waist circumference (TyG-WC), and TyG-weight-adjusted-waist index (TyG-WWI), have become valuable tools for evaluating insulin resistance in metabolic diseases. Few researches explored their links with anxiety.

METHODS

This observational study leveraged data from the National Health and Nutrition Examination Survey (2007-2012), analyzing 6726 participants to investigate the correlations between TyG-related indices and anxiety using multivariable logistic regression, subgroup analysis, and curve fitting.

RESULTS

After adjusting for confounders, significant positive correlations were identified between TyG, TyG-WWI, and anxious days [0.792 (0.262, 1.322); 0.033 (0.003, 0.063)]. These findings were reinforced when TyG-related indices were categorized into quartiles. Positive associations were further observed between TyG and anxiety state [1.243 (1.076, 1.437)], which was consistent across quartile groupings. Subgroup analyses revealed that racial stratification significantly influenced the relationship between TyG, TyG-BMI, TyG-WHtR, TyG-WC, TyG-WWI and anxious days. Gender stratification significantly influenced the relationship between TyG and anxiety state. Linear associations were established between TyG and anxious days, anxiety state with regression coefficients of 0.873 and 1.254 respectively. Non-linear relationships and threshold effects were detected, with inflection points at 187.731, 3.040, 725.288, and 104.011 (for TyG-BMI, TyG-WHtR, TyG-WC, TyG-WWI with anxious days) and 188.677, 3.059, 730.251, and 103.869 (for TyG-BMI, TyG-WHtR, TyG-WC, TyG-WWI with anxiety state).

CONCLUSIONS

These results enhance our understanding of relationships between TyG-related indices and anxiety, providing valuable insights for the prevention and management of obesity and anxiety.

The role of circRNA in insulin resistance and its progression induced by adipose inflammation

CircRNAs refer to a type of closed circular non-coding RNA without a 5' cap or a 3' poly (A) structure. They are largely distributed in the cytoplasm or localized in exosomes and cannot be easily degraded by RNA exonuclease activity. Their stable expression is broadly observed across eukaryotic species. Insulin resistance (IR) refers to the inability of insulin to exert its normal biological function, as manifested by the impairment of glucose utilization in peripheral tissues (e.g., muscle and fat tissues). IR is a key factor in the pathogenesis of Type 2 diabetes (T2D) and is closely associated with obesity. Recent studies have shown that certain circRNAs play critical roles in obesity-induced diabetes by regulating IR and participating in inflammatory processes. CircRNAs, with their multiple microRNA (miRNA) binding sites, act as miRNA sponges to eliminate the inhibitory actions of miRNAs and up-regulate the expression of target genes. CircRNAs play a significant role in regulating obesity-induced diabetes through their interactions with disease-related miRNAs. In the present study, we explored the biological characteristics of circRNAs and extensively discussed the role of circRNAs in the development of inflammation and IR in adipocytes, highlighting their potential as therapeutic targets for obesity-induced diabetes. Specific circRNAs (e.g., circARF3 and circ-ZNF609) have been identified as key players in modulating IR and inflammatory responses in adipose tissue. CircRNAs are emerging as important regulators of IR and inflammation in adipocytes, with significant potential for therapeutic intervention in obesity-induced diabetes. Further research is needed to elucidate the mechanisms underlying their actions and to explore strategies for targeting circRNAs in clinical applications.

A novel fullerene-lysine derivative with noticeable ROS scavenging capabilities for improving type 2 diabetes mellitus

As some of the most promising candidates available, fullerene-derived bioactive agents have been explored as new drugs with high efficacy and safety for biomedical applications. In this study, a fullerene-lysine derivative (C60-Lys) was synthesized successfully and proved to be good at treating type 2 diabetes mellitus (T2DM). C60-Lys could alleviate oxidative stress both in streptozotocin (STZ)-induced MIN6 cells and in STZ-induced T2DM mice subjected to a high-fat diet, and it significantly normalized glucose uptake and reduced blood glucose. In addition, C60-Lys can alleviate insulin resistance, hyperinsulinemia and lipid levels in T2DM mice. It was further confirmed that C60-Lys could alleviate oxidative stress by increasing the activities of antioxidant enzymes and stabilizing the mitochondrial membrane potential (MMP) of pancreatic β-cells to reduce the overproduction of ROS. The results provide compelling evidence that C60-Lys possesses promising applications for T2DM treatment.

Integrative Strategies for Preventing and Managing Metabolic Syndrome: The Impact of Exercise and Diet on Oxidative Stress Reduction-A Review

Metabolic syndrome (MetS) is characterized by central obesity, insulin resistance, hypertension, dyslipidemia, and chronic inflammation, significantly increasing the risk of cardiovascular disease and type 2 diabetes. Effective management of MetS is critical, with exercise being a key intervention. This review analyzed the effects of different exercise intensities-low, moderate, and high-intensity interval training (HIIT)-on metabolic health, oxidative stress (OS), inflammation, and cardiovascular function. A search of Medline, PEDro, and EBSCO identified 2251 articles, with 159 studies published between 1999 and 2025 included after screening. Low-intensity exercise improved insulin sensitivity, reduced OS markers (e.g., MDA, 8-OHdG), and enhanced antioxidant enzyme activity. Moderate-intensity exercise showed similar benefits with notable reductions in inflammatory markers (e.g., IL-1β, TNF-α). HIIT promoted fat loss and improved metabolic markers but temporarily increased OS and inflammation. Dietary strategies also play a critical role. The Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) diets are well established, emphasizing nutrient-dense foods like unsaturated fats and fiber to reduce inflammation and manage weight. The ketogenic diet (KD), a high-fat, low-carbohydrate approach, has recently gained attention for its metabolic benefits. KD induces ketosis, improving insulin sensitivity, reducing triglycerides, and enhancing fat oxidation. Studies show KD effectively reduces body weight and glucose levels, though long-term adherence and nutrient deficiencies remain challenges. Intermittent fasting also showed potential benefits, though effects on glucose metabolism were inconsistent. This review underscores the need for tailored approaches combining exercise, diet, and fasting to optimize MetS outcomes, offering integrative strategies for prevention and management.

Association Between Estimated Glucose Disposal Rate and Stroke in Middle-Aged and Older Chinese Adults: A Nationwide Prospective Cohort Study

BACKGROUND

The estimated glucose disposal rate (eGDR) is recognized as a reliable marker of insulin resistance. However, the association between eGDR and the risk of stroke remains unclear.

METHODS AND RESULTS

A total of 13 706 middle-aged and older participants were enrolled from CHARLS (China Health and Retirement Longitudinal Study). The primary end point was the occurrence of stroke events. The Kaplan-Meier curves, Cox proportional hazard models, and restricted cubic spline analysis were applied to explore the association between eGDR and the risk of stroke according to sex, age, and glycemic status. A total of 1101 stroke events were recorded. Our findings revealed a significant nonlinear relationship between eGDR and the occurrence of stroke. The association was similar between men (hazard ratio [HR], 0.83 [95% CI, 0.80-0.87]) and women (HR, 0.86 [95% CI, 0.80-0.87]), as well as among participants with normal glucose tolerance (HR, 0.83 [95% CI, 0.79-0.87]), prediabetes (HR, 0.85 [95% CI, 0.82-0.89]), and diabetes (HR, 0.87 [95% CI, 0.82-0.92]). However, the association was stronger in middle-aged participants (HR, 0.82 [95% CI, 0.78-0.86]) compared with older individuals (HR, 0.87 [95% CI, 0.83-0.90]; P for interaction=0.019).

CONCLUSIONS

This study demonstrates that lower eGDR levels are significantly linked to increased stroke risk. The relationship between eGDR and stroke risk was similar across different sexes and glycemic statuses and was stronger in middle-aged participants compared with older participants.

Nutritional and herbal interventions for polycystic ovary syndrome (PCOS): a comprehensive review of dietary approaches, macronutrient impact, and herbal medicine in management

Polycystic Ovary Syndrome (PCOS) is a common health condition related to a woman's hormonal problems. Hormonal imbalance, metabolic disorders, and an increased insulin level mainly characterize the ailment. This detailed review focuses on dietary strategies, macromolecules, macromolecules, and herbal interventions that exception-ally work in PCOS treatment. Research has shown that Mediterranean, low-glycemic index, and ketogenic diets that are modified with individuals in mind are the best ways to resolve insulin resistance, obesity, and lack of ovulation. The other nutrients shown to affect glucose metabolism and play a role in hormone regulation are the macromolecules, such as increased protein and reduced refined carbs. Among the different micronutrients, vitamin D, omega-3 fatty acids, and inositol were shown to be the most vital supplements in the treatment of PCOS-induced oxidative damage, hyperandrogenism, and infertility. Not to mention, cinnamon, curcumin, sage, fennel, and traditional Chinese herbal medicine are among some of the herbal remedies that so far show good potential to be the perfect complementary therapy tools as they create better glycemic control, inflammation reduction, and menstrual cycle regularization. Even though the findings are promising, the current supply of clinical trials for standardizing these nutritional and herbal protocols is lacking. Overall, this report stresses the fact that a customized, holistic diet regime is the best treatment for women with PCOS to make them feel well and live a long and healthy life.

Efficacy and safety of olive leaf extract (Olea europaea L.) for glycaemic control in adults with type 2 diabetes mellitus (ESOLED): A pilot randomised controlled trial

BACKGROUND

Maintaining optimum glycaemic control is essential to reducing comorbidity and mortality in diabetes. However, research indicates that <50 % of patients achieve their target HbA1c ranges. Laboratory studies suggest that olive leaf extract (OLE) may improve glycaemic control, however clinical studies in persons with diabetes are lacking.

METHODS

ESOLED is a pilot, randomised, placebo-controlled trial. Adults with a diagnosis of type 2 diabetes of ≥12 months duration, and not receiving insulin therapy, were eligible to participate. Participants were randomised to receive OLE or placebo capsules for 24 weeks. The primary outcome was change in HbA1c. Secondary outcomes included changes in the homeostasis model assessment of insulin resistance, diabetes-related stress, health-related quality of life, and safety.

RESULTS

Thirty-one participants were randomly assigned to the OLE (n = 16) and placebo (n = 15) groups. Analyses found no statistically significant time-group interactions for HbA1c, diabetes-related distress or health-related quality of life. Although participants receiving OLE demonstrated greater improvements in insulin sensitivity than those on placebo, there was no significant difference between groups over time. OLE and placebo were found to be well-tolerated, with no severe or serious adverse events reported in either group.

CONCLUSION

The ESOLED trial has provided preliminary evidence on the tolerability of OLE in adults with type 2 diabetes, but was inconclusive in determining whether OLE is effective at improving glycaemic control, insulin sensitivity, diabetes-related distress and quality of life. Larger trials and further exploration of the bioavailability of OLE are needed to fully assess the therapeutic potential of OLE in diabetes.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12622000616774).

Sex-specific association between triglyceride-glucose index and all-cause mortality in patients with osteoporotic fractures: a retrospective cohort study

Background

Osteoporotic fractures (OPFs) pose a considerable global health burden and are linked with an elevated mortality risk. The triglyceride-glucose index (TyG-I) is a recognized marker of insulin resistance across various populations. The association between all-cause mortality (ACM) and the TyG-I has been widely investigated in a variety of clinical settings. The potential sex-specific differences in this association among OPF patients remain uncertain.

Methods

In this retrospective cohort study, 2,307 patients ≥ 50 years old admitted to the hospital between January 2018 and August 2023 for surgical treatment of OPFs were included. The TyG-I was determined using fasting triglyceride and glucose levels measured at admission. The association between ACM and the TyG-I was evaluated by Cox proportional hazards regression, adjusting for possible confounding variables. Analyses were categorized by sex, and subgroup analyses evaluated possible interaction effects. The ACM rates among TyG-I tertiles were compared via Kaplan-Meier curves.

Results

This research study analyzed 2,307 patients, of whom 247 (10.71%) died from any cause during the follow-up period. In females, a linear association of the TyG-I with ACM was observed even after adjusting for confounders, with each unit increase in the TyG-I correlating with a 37% increased risk of death (HR: 1.37, 95% CI: 1.06-1.77, p = 0.02). However, in males, there was a non-linear correlation, where patients in the uppermost TyG-I tertile showed a substantially decreased mortality risk relative to those in the lowest tertile (HR: 0.53, 95% CI: 0.30-0.92, p = 0.02). TyG-I indicated a statistically significant relation with sex (P for interaction = 0.01).

Conclusion

In patients diagnosed with OPFs, distinct sex-specific variations were observed in the relationship between ACM and the TyG-I. Among female patients, each unit increase in the TyG-I was linked to a 37% greater risk of mortality. Conversely, male patients within the highest TyG-I tertile indicated a lower mortality risk than those in the lowest tertile. Further research is required to confirm these sex-specific associations.

Associations between insulin resistance and low back pain risk in US adults: a cross-sectional study

Background

Insulin resistance is one of the major pathophysiological features of type 2 diabetes mellitus. Studies have revealed the association between type 2 diabetes mellitus and low back pain. However, few studies explored the relationship between insulin resistance and low back pain directly. Therefore, this study selected HOMA-IR, TyG, TyG-BMI, TyG-WC, and TyG-WtHR as indicators of insulin resistance to comprehensively investigate the association between insulin resistance and low back pain.

Methods

The data for this cross-sectional study were from NHANES. Multivariate logistic regression was used to assess the association of insulin resistance with low back pain, and the stability of the results was evaluated by stratified analysis.

Results

A total of 6,126 adult participants were included in the study, including 3,657 non-LBP participants and 2,469 LBP patients. All of these five indices showed significant association with low back pain after full adjustment for all covariates (Model 3), HOMA-IR [OR = 1.052, 95% CI (1.018, 1.087), p = 0.003], TyG [OR = 1.431, 95% CI (1.013, 2.021), p = 0.042], TyG-BMI [OR = 1.003, 95% CI (1.002, 1.005), p < 0.0001], TyG-WC [OR = 1.001, 95% CI (1.001, 1.002), p < 0.0001], TyG-WtHR [OR = 1.268, 95% CI (1.155, 1.393), p < 0.0001]. The relationship between insulin resistance and low back pain is stable in most stratified populations (p-interaction >0.05).

Conclusion

Insulin resistance is associated with an increased risk of low back pain. The HOMA-IR, TyG, TyG-WC, TyG-BMI, and TyG-WtHR all showed a stable correlation with low back pain. TyG-BMI, TyG-WC, and TyG-WtHR are more stable in their associations with low back pain than TyG alone.

Palmitic acid-induced insulin resistance triggers granulosa cell senescence by disruption of the UPRmt/mitophagy/lysosome axis

Insulin resistance (IR) is the main pathological feature of polycystic ovary syndrome (PCOS), but the adverse impacts of IR on ovary and granulosa cells (GCs) are unknown. Therefore, the role of palmitic acid (PA) induced IR in GCs, and a mitochondrial proteostasis and mitochondrial homeostasis control system, the mitochondrial unfolded protein response (UPRmt)/mitophagy/lysosome axis were investigated to uncover the side effect and the mechanism of IR on GCs. Our results revealed that IR in GC was successfully constructed by 100 μM PA treatment accompanied with cell senescence. In addition, mitochondrial function was impaired by IR-induced GC senescence accompanied by significantly increased reactive oxygen species (ROS) and decreased mitochondrial membrane potential, and mitochondrial proteostasis was impaired by a dysfunctional UPRmt and increased protein aggregation, leading to more unfolded and misfolded proteins accumulating in mitochondria. Mitochondrial homeostasis was maintained by the mitophagy/lysosome degradation system, although mitophagy was significantly increased, lysosomes were damaged; hence, malfunctional mitochondria were not cleared by the mitophagy/lysosome degradation system, more ROS were produced by malfunctional mitochondria. Therefore, accelerated GC senescence was triggered by excessive ROS, and reversed by the mitophagy inhibitor cyclosporin A (CsA) accompanied with reduced IR. Additionally, the mice were administered with PA, and results revealed that the accelerated ovarian aging was caused by PA, which might be attributed to GC senescence. In conclusion, GC senescence was triggered in PA-induced IR by disruption of the UPRmt/mitophagy/lysosome axis, and IR induced GC senescence was reversed by the CsA.

Impact of body mass index on the association between kidney function and insulin resistance in diabetic and nondiabetic populations

AIMS/INTRODUCTION

The kidneys play a role in regulating insulin metabolism, and kidney function may indicate the progression to insulin resistance (IR) in individuals with obesity and diabetes. We evaluated the relationship between kidney function biomarkers and IR in diabetic and nondiabetic adults categorized by body mass index (BMI).

METHODS

A total of 8,272 adults from the China Health and Nutrition Survey 2009 were categorized into four groups based on BMI (overweight/obesity vs underweight/normal weight) and diabetes status (diabetes vs non-diabetes). Univariable and multivariable linear regression, along with restricted cubic spline regression, were used to determine the relationship between estimated glomerular filtration rate (eGFR), creatinine, urea nitrogen, uric acid (UA), and homeostasis model assessment for insulin resistance (HOMA-IR).

RESULTS

The relationship between kidney function biomarkers and IR only existed in the overweight/obese populations and varied by diabetic status. In diabetic patients, linear associations were observed: eGFR was negatively associated with HOMA-IR, and creatinine was positively associated. In nondiabetic individuals, nonlinear associations were found. The relationship between eGFR and HOMA-IR followed an L-shaped curve: HOMA-IR decreased as eGFR increased up to 100 mL/min/1.73 m2, then slightly increased. The UA-HOMA-IR association showed an inverted L-shape: HOMA-IR increased with higher UA levels, plateauing after UA exceeded 360 μmol/L.

CONCLUSIONS

Kidney function biomarkers are associated with IR in overweight/obese populations, with and without diabetes. eGFR and creatinine can be indicators of IR in overweight/obese subjects with diabetes, while eGFR and UA may be used in those without diabetes.

Triglyceride/high-density lipoprotein cholesterol ratio associates major adverse cardiac and cerebrovascular events: a 13-year prospective cohort study

BACKGROUND

Few studies have been conducted to investigate the association between the triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio and major adverse cardiac and cerebrovascular events (MACCEs) in a predominantly male cohort from China.

METHODS

A prospective cohort study was conducted on a total 95,837 individuals (males account for 79.67) extracted from the Kailuan study. All individuals were grouped according to the TG/HDL-C ratio quartile. The endpoints of this study were composite MACCEs and its subtypes [non-fatal myocardial (MI), non-fatal stroke and all-cause mortality]. The Kaplan-Meier method was employed to illustrate the cumulative incidence curve. The incidence rate was reported as per 1000 person-years. To explore the impact of varying quartiles of the TG/HDL-C ratio on the risk of MACCEs, Cox proportional hazard regression analysis was conducted. Furthermore, multivariate adjusted spline regression models were applied to examine the relationship between the TG/HDL-C ratio and the risk of MACCEs.

RESULTS

A total of 18,430 cases of composite MACCEs occurred during a 13.97-year follow-up. In brief, 1762 cases of MI, 6653 cases of stroke, and 12,524 cases of all-cause mortality were reported, respectively. The cumulative incidence and incidence rate of composite MACCEs, MI, and stroke increased with increment in the TG/HDL-C ratio (p < 0.001). In comparison to quartile 1, the hazard ratios of quartile 4 for composite MACCEs, MI, stroke, and all-cause mortality were 1.13 (95% CI 1.07-1.19), 1.55 (95% CI 1.30-1.84), 1.21 (95% CI 1.12-1.31), and 1.12 (95% CI 1.05-1.20), respectively. Multivariate adjusted spline regression models showed a nonlinear relationship between baseline TG/HDL-C ratio and risk of composite MACCEs (p for non-linearity < 0.01), MI (p for non-linearity < 0.01), stroke (p for non-linearity < 0.01), and all-cause mortality (p for non-linearity = 0.029).

CONCLUSIONS

The TG/HDL-C ratio is significantly associated with an increased risk of MACCEs in a predominantly male cohort from northern China.

Association between triglyceride glucose-body mass index and 365-day mortality in patients with critical coronary heart disease

Objectives

The aim of this study was to analyze the association between TyG-BMI and 365-day mortality in critically ill patients with CHD.

Methods

Patient data were extracted from the MIMIC-IV database. All patients were categorized into 3 groups based on TyG-BMI index: Low TyG-BMI index group, Medium TyG-BMI index group, and High TyG-BMI index group. Outcomes included primary and secondary outcomes, with the primary outcome being 365-day mortality and the secondary outcomes being hospital survival, intensive care unit (ICU) survival, and 28-day, 90-day, and 180-day mortality. The Kaplan-Meier survival curves were used to compare the outcomes of the three groups. The relationship between TyG-BMI index and 365-day mortality was assessed using multivariate Cox proportional risk regression models and restricted cubic spline curves (RCS).

Results

889 critically ill patients with CHD were analyzed. Among them, 600 (67.50%) were male patients with a mean age of 68.37 years and 289 (32.50%) were female patients with a mean age of 73.91 years. Patients with a medium TyG-BMI index had the best 365-day prognostic outcome and the highest survival rate compared with patients in the Low and High TyG-BMI index groups [201 (67.68%) vs. 166 (56.08%), 188 (63.51%); P=0.013]. After fully adjusted modeling analysis, the hazard ratio (HR) for 365-day mortality was found to be 0.71 (95% CI 0.54-0.93, P=0.012) for the Medium TyG-BMI index group. Meanwhile, RCS analysis showed an L-shaped relationship between TyG-BMI index and 365-day mortality.

Conclusions

The TyG-BMI index is significantly associated with 365-day mortality in patients with severe CHD.

The Association between the Triglyceride-Glucose Index and the Incidence Risk of Parkinson's Disease: A Nationwide Cohort Study

OBJECTIVE

We aimed to investigate the associations of the triglyceride-glucose index, which measures insulin resistance, and the incidence of Parkinson's disease.

METHODS

Our study used the Health Screening Cohort database of the National Health Insurance Service of South Korea (2002-2019). We included 310,021 participants who had no previous history of Parkinson's disease and for whom more than 3 triglyceride-glucose index measurements were available. A diagnosis of Parkinson's disease was determined via the International Classification of Diseases Tenth edition (G20) with a specific reimbursement code for rare intractable diseases and a history of prescriptions for anti-Parkinsonism drugs.

RESULTS

During a median of 9.64 years (interquartile range 8.72-10.53), 4,587 individuals (1.5%) had Parkinson's disease. Based on a multivariable time-dependent Cox proportional hazards model, a per-unit increase in triglyceride-glucose index score was associated with a significantly increased risk of Parkinson's disease (hazard ratio [HR]: 1.062; 95% confidence interval [CI] 1.007-1.119). In a sensitivity analysis, the triglyceride-glucose index was associated with the incidence of Parkinson's disease in a non-diabetes mellitus cohort (HR: 1.093; 95% CI 1.025-1.165), but not in the diabetes mellitus cohort (HR: 0.990; 95% CI 0.902-1.087). In a restricted cubic spline analysis, the association between the triglyceride-glucose index and the incidence risk of Parkinson's disease showed a nonlinear increasing (J-shaped) trend.

CONCLUSION

Our study demonstrated that higher triglyceride-glucose index scores were associated with the incidence of Parkinson's disease in the general population, particularly in a nondiabetic mellitus cohort.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

Clinicaltrials.gov ID: NCT05616013.

Prediction of insulin resistance using multiple adaptive regression spline in Chinese women

Insulin resistance (IR) is the core for type 2 diabetes and metabolic syndrome. The homeostasis assessment model is a straightforward and practical tool for quantifying insulin resistance (HOMA-IR). Multiple adaptive regression spline (MARS) is a machine learning method used in many research fields but has yet to be applied to estimating HOMA-IR. This study uses MARS to build an equation to estimate HOMA-IR in pre-menopausal Chinese women based on a sample of 4,071 healthy women aged 20-50 with no major diseases and no medication use for blood pressure, blood glucose or blood lipids. Thirty variables were applied to build the HOMA-IR model, including demographic, laboratory, and lifestyle factors. MARS results in smaller prediction errors than traditional multiple linear regression (MLR) methods, and is thus more accurate. The model was established based on key impact factors including waist-hip ratio (WHR), C reactive protein (CRP), uric acid (UA), total bilirubin (TBIL), leukocyte (WBC), serum glutamic oxaloacetic transaminase (GOT), high-density lipoprotein cholesterol (HDL-C), systolic blood pressure (SBP), serum glutamic pyruvic transaminase (GPT), and triglycerides (TG). The equation is as following:HOMA-IR = 6.634 - 1.448MAX(0, 0.833 - WHR) + 10.152MAX(0, WHR - 0.833) - 1.351MAX(0, 0.7 - CRP) - 0.449MAX(0, CRP - 0.7) + 1.062MAX(0, UA - 8.5) + +1.047(MAX(0, 0.83 - TBIL) + 0.681MAX(0, WBC - 11.53) - 0.071MAX(0, 11.53 - WBC) + 0.043MAX(0, 24 - GOT) - 0.017MAX(0, GOT - 24) + 0.021MAX(0, 59 - HDL) - 0.005MAX(0, HDL - 59) - 0.013MAX(0, 141 - SBP) - 0.033MAX(0, 100 - GPT) + 0.013MAX(0, GPT - 100) - 0.004MAX(303 - TG)Results indicate that MARS is a more precise tool than fasting plasma insulin (FPI) levels, and could be used in the daily practice, and further longitudinal studies are warranted.

Thyroid Stimulating Hormone Levels Are Related to Fatty Liver Indices Independently of Free Thyroxine: A Cross-Sectional Study

Introduction: The relationship between metabolic dysfunction-associated steatotic liver disease (MASLD) and thyroid hormones has been established, but the direct effects of TSH on the liver, potentially leading to steatosis, and insulin resistance remain unclear. Objective: To investigate the association of TSH levels with MASLD and insulin resistance. Methods: We conducted a cross-sectional study of 8825 euthyroid individuals. Subjects were volunteers or patients referred to the International Center for Nutritional Status Assessment (University of Milan, Italy) undergoing clinical examination and blood drawing for thyroid function tests and liver indices calculation. Liver outcomes were fatty liver index (FLI), hepatic steatosis index (HSI), and FIB-4. All associations were adjusted for fT4 and confounders. Results: We found a positive association of TSH levels with FLI (β = 2.76; p < 0.001) and HSI (β = 0.58, p < 0.001). This relationship remained significant when stratifying by sex and BMI category, except for HSI in normal weight individuals. No significant association was found between TSH and hepatic fibrosis or insulin resistance. Conclusions: We found a positive association between TSH levels and MASLD in euthyroid individuals independently of fT4, sex, and BMI. Insulin resistance and hepatic fibrosis appear unrelated to TSH, independent of fT4 and BMI. The specific role of TSH in MASLD warrants further investigation.

Cardioprotective role of SIRT1 activation on mitochondrial function in insulin-resistant H9c2 cells

BACKGROUND

Insulin-resistance in cardiomyocytes is often associated with metabolic disorders like obesity, and type2 diabetes. Studies demonstrated that sirtuin1 (SIRT1) plays a protective role in cells resistant to insulin by enhancing insulin sensitivity and improving glucose metabolism. Based on these protective functions observed in SIRT1, this study aims to investigate the roles of SIRT1 in palmitate (PA)-induced insulin-resistant H9C2 cells.

METHODS

Insulin-resistance was induced in H9c2 cells via incubation with palmitic acid (50µM;24 h). Control and Insulin-resistant cells were incubated with SIRT1 inhibitor (EX527;10µM) and SIRT1 activator (SRT1720;2µM) for 24 h, respectively. Mitochondrial membrane potential (MMP), reactive oxygen/nitrogen species (ROS/RNS), total ATP production, intracellular free zinc and calcium levels ([Ca2+]i and [Zn2+]i) were monitored with fluorescence techniques. Protein levels were determined by using western-blot analysis.

RESULTS

K-acetylation level was increased in PA-induced Insulin-resistant cells and SIRT1 inhibited control cells. ROS/RNS production, [Ca2+]i, and [Zn2+]i levels were elevated, MMP was depolarized and ATP production was decreased in PA and EX527 treated cells compared to control cells. Mfn1 and Fis1 levels were remained unchanged, however Mfn2 protein level was elevated in cells treated with PA and SIRT1 inhibitor. Nevertheless, anti- and pro-apoptotic protein level was reduced and augmented respectively in insulin-resistant and SIRT1 inhibited cells. Activation of SIRT1 in PA-treated cells restored mitochondrial function and intracellular ionic homeostasis, reduced K-acetylation, and mitigated apoptosis.

CONCLUSION

Therefore, it can be proposed that the activation of SIRT1, acting as a novel regulator, may offer direct cardioprotection by restoring mitochondrial function in the insulin-resistant heart.

Associations between estimated glucose disposal rate and osteoarthritis risk in US adults: a cross-sectional study

BACKGROUND

Estimated glucose disposal rate (eGDR) is a novel insulin resistance (IR) assessment surrogate. Although it has shown promising potential in other metabolic disease studies, no research has yet explored its relationship with osteoarthritis (OA). Therefore, this study aims to investigate the association between eGDR and OA in a cross-sectional observational cohort.

METHOD

Data utilized in this cross-sectional study were drawn from the National Health and Nutrition Examination Survey (NHANES). Logistic regression models were used to evaluate the association between eGDR and OA, stratified analysis was applied to assess the stability of the results.

RESULT

A total of 19,040 participants were included in the study, including 2,001 OA patients and 17,039 non-OA participants with an age distribution ranging from 20 to 85 years. The fully adjusted logistic regression model shows that eGDR were less likely associated with OA compared to those with non-OA (OR = 0.879, 95% CI = 0.846-0.914, P < 0.001). By dispersing the eGDR into quartiles, the correlation between eGDR and OA remained significant (P for trend < 0.0001).

CONCLUSION

This study suggests that eGDR is independently associated with OA, with lower eGDR values being linked to a higher risk of OA.

CLINICAL TRIAL NUMBER

Not applicable.

Association between C-reactive protein-triglyceride glucose index and stroke risk in different glycemic status: insights from the China Health and Retirement Longitudinal Study (CHARLS)

OBJECTIVE

C-reactive protein-triglyceride-glucose index (CTI) has been proposed as a novel biomarker for insulin resistance and inflammation. However, the association between CTI and the risk of stroke, particularly in individuals with different glycemic status, remains unclear.

METHODS

A total of 10,443 middle-aged and elderly participants were enrolled from the China Health and Retirement Longitudinal Study (CHARLS). The primary endpoint was the occurrence of stroke events. The CTI was calculated using the formula 0.412* Ln (CRP [mg/L]) + Ln (TG [mg/dl] × FPG [mg/dl])/2. The Kaplan-Meier curves, Cox proportional hazard models, and restricted cubic spline analysis were applied to explore the association between CTI and the risk of stroke according to gender, age and glycemic status.

RESULTS

During a median follow-up of 9 years, 960 (9.2%) participants experienced a stroke. Our findings revealed a significant positive linear relationship between CTI and the occurrence of stroke. The association was similar between male and female, despite the HR tended to be higher in females (HR 1.22, 95% CI 1.09, 1.36) than males (HR 1.15, 95% CI 1.02, 1.29), and similar in middle-aged (HR 1.25, 95% CI 1.11, 1.41) and elderly participants (HR 1.12, 95% CI 1.00, 1.26). In different glycemic status, high levels of CTI were found to be linked to an increased risk of stroke in individuals with normal glucose regulation (NGR) (HR 1.33, 95% CI 1.11, 1.59) and prediabetes mellitus (Pre-DM) (HR 1.20, 95% CI 1.04, 1.39). However, this association was not observed in individuals with diabetes mellitus (DM).

CONCLUSIONS

Our findings revealed a significant positive linear relationship between CTI and the occurrence of stroke. The association between CTI and stroke was similar between male and female, and similar in middle-aged and elderly participants. In different glycemic status, the association was significant in individuals with NGR and Pre-DM.

Neonatal and Syndromic Forms of Diabetes

PURPOSE OF REVIEW

Neonatal and syndromic diabetes are rare but important conditions. These conditions often result in severe insulin deficiency or insulin resistance. In this review, we aim to discuss the clinical characteristics and genetics of neonatal and syndromic forms of diabetes.

RECENT FINDINGS

Beyond the development of diabetes mellitus, many other organ systems are affected. Understanding the pathophysiology of these conditions have improved our collective understanding of the genetics and developmental biology related to glucose metabolism and beyond. This review will provide new information for researchers and provide a helpful resource for clinicians when evaluating a patient for neonatal and syndromic forms of diabetes.

The role of PTP1B in cardiometabolic disorders and endothelial dysfunction

Cardiovascular diseases (CVD) are a global health concern that accounts for a large share of annual mortality. Endothelial dysfunction is the main underlying factor that eventually leads to cardiovascular events. Recent studies have underscored the critical function of Protein Tyrosine Phosphatase 1B (PTP1B) in the onset of endothelial dysfunction, chiefly through its involvement in metabolic diseases such as diabetes, obesity, and leptin resistance. PTP1B attenuates insulin and leptin signalling by dephosphorylating their respective receptors at key tyrosine residues, resulting in resistance-both of which are significant mechanisms underpinning the development of endothelial dysfunction. PTP1B also contributes to the disruption of the endoplasmic reticulum, causing endoplasmic reticulum stress, another molecular driver of endothelial dysfunction. Efforts to inhibit PTP1B activity hold the promise of advancing the prevention and management of CVD and metabolic disorders, as these conditions share common risk factors and underlying cellular mechanisms. Numerous small molecules have been reported as PTP1B inhibitors; however, their progression to advanced clinical trials has been hindered by major challenges such as low selectivity and undesirable side effects. This review provides an in-depth analysis of PTP1B's involvement in metabolic diseases and its interaction with CVD and examines the strategies and challenges related to inhibiting this enzyme.

Insulin resistance and beta-cell dysfunction in adults with different patterns of diet: a cross-sectional study in north-western Tanzania

BACKGROUND

The diabetes burden in sub-Saharan Africa is rising, but there is little African data on associations between diet, insulin resistance, and beta-cell dysfunction.

OBJECTIVE

We investigated the association between dietary patterns and insulin resistance and beta-cell dysfunction among adults in Mwanza, Tanzania.

METHODS

In a cross-sectional study involving adults with or without HIV, insulin resistance and beta-cell dysfunction were calculated from plasma insulin and glucose measures during an oral glucose tolerance test. Diet data were collected using a validated food frequency questionnaire and dietary patterns were derived by principal component analysis and reduced rank regression. Logistic regression analysis was used to assess the association between exposure variables (dietary patterns terciles) with outcome variables (insulin resistance and beta-cell dysfunction), adjusting for HIV status, age, sex, body mass index, alcohol consumption, and smoking.

RESULTS

Of 462 participants, the mean age was 42 (±12) years, 58% were females, and 60% were HIV-infected. Carbohydrate-dense patterns were associated with more insulin resistance by HOMA-IR (aOR 2.7, 95% CI 1.5; 4.8) and Matsuda index (aOR 3.7, 95% CI 2.0; 6.7), but not with either HOMA-β, insulinogenic index or oral disposition index. The level of adherence to either the vegetable-rich or vegetable-poor pattern was not associated with any of the markers of insulin resistance or beta-cell dysfunction. HIV infection did not affect the association between patterns of diet and glucose metabolism outcomes.

CONCLUSION

The lack of association between either vegetable-rich or vegetable-poor patterns with insulin resistance or beta cell dysfunction requires further research.

Individuation of a cut-off value of triglyceride-glucose index for incident diabetes mellitus in patients with essential hypertension

The prevalence of obesity and diabetes, risk factors for atherosclerotic vascular diseases, is increasing worldwide; therefore, it is desirable to early identify them to reduce cardiovascular events. Thus, we investigated whether the triglyceride-glucose index (TyG index), a new marker of insulin resistance, is associated with incident diabetes in patients with newly diagnosed arterial hypertension. We selected 585 patients with newly diagnosed arterial hypertension referred to our tertiary Clinic of Catanzaro University Hospital for the evaluation of their cardiometabolic risk profile. None of the patients had diabetes mellitus at enrollment and took any drug known to affect glucose metabolism. Patients underwent medical history collection, clinical examination and laboratory tests. The TyG index was calculated as the ln [fasting TG (mg/dl) × FPG (mg/dl)/2], as previously suggested. During the follow-up [mean 8.5 years (range 3.1-10.7)], there were 78 new cases of incident diabetes (1.57% patient-year). Patients who developed diabetes mellitus were older and had a higher body mass index (BMI), baseline blood pressure, fasting glucose, insulin, homeostatis model sssessment (HOMA) index, triglyceride, creatinine and hs-CRP mean values, while estimated glomerular filtration rate values were lower. At the Cox regression analysis, covariates significantly associated with incident diabetes were: BMI (HR = 2.842, 95%CI = 2.299-3.514), TyG index (HR = 2.392, 95%CI = 1.745-3.192), age (HR = 1.944, 95%CI = 1.527-2.474), hs-CRP (HR = 1.409, 95%CI = 1.153-1.722), and HOMA (HR = 1.325, 95%CI = 1,079-1.756). The best estimated cut-off value of TyG index in predicting diabetes was 4.71. In addition, we documented a significant relationship between TyG index and HOMA (r = 0.575; p < 0.0001). Present data demonstrate that TyG index, a simple and cost-effective marker of insulin resistance, is useful in predicting incident diabetes in patients with arterial hypertension.

Impact of Meal Frequency on Insulin Resistance in Middle-Aged and Older Adults: A Prospective Cohort Study

BACKGRUOUND

Insulin resistance (IR) is central to metabolic disorders and significantly influenced by diet. Studies on meal frequency (MF) and metabolic indicators have shown mixed results. This study explores the link between MF and IR in middle-aged and older adults.

METHODS

This prospective cohort study included 4,570 adults aged 40 to 69 years from the Korean Genome and Epidemiologic Study. MF were divided into two groups based on whether they consumed three or more, or fewer than three, meals daily. IR was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR); participants were classified as IR if their HOMA-IR value was ≥2.5. Multiple Cox proportional hazard regression analyses were conducted to examine the association between MF and the incidence of IR.

RESULTS

After adjusting for all variables, individuals in the MF ≥3 group showed a reduced incidence of IR compared to those in the MF <3 group (hazard ratio, 0.880; 95% confidence interval, 0.782 to 0.990). Additionally, subgroup analyses by sex, diabetes mellitus (DM), and body mass index (BMI) showed that this association persisted only in men, individuals without DM, and those with a BMI <25.

CONCLUSION

Our findings indicate that a higher MF among middle-aged and older adults is associated with a reduced incidence of IR. However, this association was maintained only in men, individuals without DM, and those without obesity.

Association between METS-IR index and obstructive sleep apnea: evidence from NHANES

Insulin resistance (IR) is strongly associated with obstructive sleep apnea (OSA). Whereas, few studies have focused on the potential association between the Metabolic Score for Insulin Resistance (METS-IR), a novel non-insulin-dependent IR index, and OSA. Subjects from the National Health and Nutrition Examination Survey (NHANES) spanning 2005-2008 and 2015-2018 were recruited. The potential relationship between METS-IR and other IR indices with OSA was explored through three logistic regression analysis models and restricted cubic spline (RCS) curves. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value of these indicators for OSA. On the basis of age, sex, race, body mass index (BMI), hypertension, diabetes， and cardiovascular disease (CVD), subgroup analyses were conducted to test the robustness of the METS-IR and OSA relationship. A total of 8,306 participants were enrolled, with an OSA prevalence of 30.69%. After adjusting for potential confounders, METS-IR, the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, the triglyceride glucose Index (TyG), and the homeostatic model assessment of insulin resistance (HOMA-IR) showed positive associations with OSA prevalence. In the highest tertile of METS-IR, TG/HDL-C, TyG index, and HOMA-IR, OSA prevalence was 2.96-fold, 1.42-fold, 1.29-fold, and 1.41-fold higher, respectively, compared to the lowest tertile (METS-IR: OR = 2.96, 95% CI: 2.50, 3.52, P < 0.0001; TG/HDL-C: OR = 1.42, 95% CI: 1.17, 1.73, P < 0.001; TyG index: OR = 1.29, 95% CI: 1.07, 1.55, P = 0.008; HOMA-IR: OR = 1.41, 95% CI: 1.18, 1.69, P < 0.001). ROC analysis revealed that METS-IR had the highest diagnostic accuracy for OSA (AUC = 0.652). The positive associations between these four IR indices and OSA remain stable across most cases (P for interaction > 0.05); however, all of them show significant interactions with diabetes (P for interaction < 0.05). The METS-IR index is positively associated with the prevalence of OSA and shows superior diagnostic accuracy compared to HOMA-IR, TG/HDL-C, and TyG index.

Iron Status Correlates Strongly to Insulin Resistance Among US Adults: A Nationwide Population-Based Study

CONTEXT

Evidence on the link between iron status markers and insulin resistance (IR) is limited.

OBJECTIVE

We aimed to explore the relationship between iron status and IR among US adults.

METHODS

This study involved 2993 participants from the National Health and Nutrition Examination Survey (NHANES) 2003-2006, 2017-2020. IR is characterized by a homeostatic model assessment (HOMA)-IR value of ≥2.5. Weighted linear and multivariable logistic regression analyses were used to examine the linear relationships between iron status and IR. Furthermore, restricted cubic splines (RCS) were used to identify the nonlinear dose-response associations. Stratified analyses by age, sex, body mass index, and physical activity were also performed. Last, a receiver operating characteristic (ROC) curve was used to evaluate the predictive value of iron status in IR.

RESULTS

In weighted linear analyses, serum iron (SI) exhibited a negative correlation with HOMA-IR (β -0.03, 95% CI -0.05, -0.01, P = .01). In weighted multivariate logistic analyses, iron intake and the serum transferrin receptor (sTfR) were positively correlated with IR (OR 1.02, 95% CI 1.00-1.04, P = .04; OR 1.07, 95% CI 1.02-1.13, P = .01). Also, SI and transferrin saturation (TSAT) were negatively correlated with IR (OR 0.96, 95% CI 0.94-0.98, P < .0001; OR 0.98, 95% CI 0.97-0.99, P < .001) after adjusting for confounding factors. RCS depicted a nonlinear dose-response relationship between sTfR and TSAT and IR. This correlation remained consistent across various population subgroups. The ROC curve showed that TSAT performed better than iron intake, SI and sTfR in ROC analyses for IR prediction.

CONCLUSION

All biomarkers demonstrated significantly lower risk of IR with increasing iron levels, which will contribute to a more comprehensive and in-depth understanding of the relationship between the 2 and provide a solid foundation for future exploration of the mechanisms underlying their relationship.

Apoptosis in polycystic ovary syndrome: Mechanisms and therapeutic implications

Polycystic ovary syndrome (PCOS) is a common disorder that affects the female reproductive system, with an incidence of 8 % to 15 %. It is characterized by irregular menstruation, hyperandrogenemia, and polycystic abnormalities in the ovaries. Nevertheless, there is still much to learn about the molecular pathways underlying PCOS. Apoptosis is the process by which cells actively destroy themselves, and it is vital to an organism's ability to develop normally and maintain homeostasis. In recent years, a growing body of research has indicated a connection between the pathophysiology of PCOS and apoptosis. Therefore, it is critical to comprehend the relationship between PCOS and apoptosis in greater detail, identify the pathophysiological underpinnings of PCOS, and provide fresh perspectives and targets for its treatment. This review aims to summarize the relationship between PCOS and apoptosis, discuss how apoptosis affects normal ovarian function and how it becomes dysfunctional in the ovaries of PCOS patients, and investigate the signaling pathways associated with apoptosis in PCOS, including PI3K-Akt, TNF, NF-κB, and p53. Additionally, potential therapeutic approaches for PCOS treatment are provided by summarizing the role of apoptosis in PCOS therapy.

Association Between Triglyceride-Glucose Index and Carotid Plaque Stability in Different Glycemic Status: A Single-Center Retrospective Study

BACKGROUND

The triglyceride-glucose (TyG) index has been proposed as a reliable marker of insulin resistance. However, its value in patients with carotid plaque stability remains unclear. This study investigated the association between the TyG index and unstable carotid plaque.

METHODS

A total of 12 068 participants were enrolled. Carotid ultrasound was used to determine the stability of carotid plaque. Logistic regression was used to analyze the relationship between the TyG index and unstable carotid plaque. The relationship between the TyG index and unstable carotid plaque was evaluated according to sex, age, and glucose metabolism states. Further, the dose-response relationship between the TyG index and unstable carotid plaque was also determined by restrictive cubic splines.

RESULTS

Of the 12 068 participants, 11 601 had stable carotid plaque and 467 had unstable carotid plaque. In several different adjustment models, the TyG index is significantly related to the risk of unstable carotid plaque. The association between the TyG index and an unstable carotid plaque was similar between men and women, despite the fact that the odds ratio (OR) tended to be higher in men (OR, 2.80 [95% CI, 2.04-3.83]) than women (OR, 2.07 [95% CI, 1.51-2.82]), and higher in older patients (aged >60 years; (OR, 3.59 [95% CI, 2.74-4.70]) than middle-aged patients (aged ≤60 years) (OR, 2.00 [95% CI, 1.36-2.95]). The TyG index of patients with different glycemic status was significantly correlated with the risk of unstable carotid plaque, among which the OR value of diabetes (OR, 2.51 [95% CI, 1.87-3.36]) was the highest. The restrictive cubic spline analysis indicated a nonlinear relationship between the TyG index and unstable carotid plaque, with TyG index >8.63 identified as an independent risk factor for unstable carotid plaque.

CONCLUSIONS

The TyG index has a significant association with unstable carotid plaque. The association between the TyG index and unstable carotid plaque is similar between men and women, and the association in older patients is higher than that in middle-aged patients. In different glycemic status, the association between the TyG index and unstable carotid plaque is highest in patients with diabetes.

Association Between Triglyceride/High-Density Lipoprotein Ratio and Incidence Risk of Heart Failure: A Population-Based Cohort Study

Background/Objectives: The triglyceride/high-density lipoprotein (TG/HDL) ratio serves as a simple marker for insulin resistance. We investigated whether the TG/HDL ratio would be associated with the incidence risk of heart failure (HF). Methods: The study utilized data from the National Health Insurance Service-Health Screening Cohort database of South Korea from 2002 to 2019. The TG/HDL ratio was utilized as a time-dependent covariate or average value of at least three times throughout the follow-up period. The outcome of interest was incident heart failure (HF) corresponding with the International Classification of Disease, Tenth Revision code of I50. Results: A total of 293,968 individuals were included in this study. During the median 9.6 years (interquartile range 9.2-10.13), 27,852 individuals (9.47%) had a cumulative incidence of HF. Considering the multivariable time-dependent Cox proportional hazard model with the repeated measures of the TG/HDL ratio, per unit increase in the TG/HDL ratio significantly increased the risk of HF in the entire cohort (hazard ratio (HR): 1.007, 95% confidence interval (CI): 1.002-1.011), diabetes mellitus (DM) cohort (HR: 1.006. 95% CI: 1.002-1.010), and non-DM cohort (HR: 1.008, 95% CI: 1.003-1.013). Regarding average TG/HDL ratio quartiles, compared to the lowest quartiles (Q1), the highest quartiles (Q4) were positively associated with the incidence risk of HF accompanied by a significant p for trend (HR: 1.114, 95% CI: 1.075-1.155) in fully adjusted multivariable analysis. Conclusions: Our study demonstrated that the repeatedly measured TG/HDL ratio was associated with the incidence risk of HF regardless of the presence of DM history in the general population.

Heme oxygenase, biliverdin reductase, and bilirubin pathways regulate oxidative stress and insulin resistance: a focus on diabetes and therapeutics

Metabolic and insulin-resistant diseases, such as type 2 diabetes mellitus (T2DM), have become major health issues worldwide. The prevalence of insulin resistance in the general population ranges from 15.5% to 44.6%. Shockingly, the global T2DM population is anticipated to double by 2050 compared with 2021. Prior studies indicate that oxidative stress and inflammation are instrumental in causing insulin resistance and instigating metabolic diseases. Numerous methods and drugs have been designed to combat insulin resistance, including metformin, thiazolidinediones (TZDs), sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon-like peptide 1 receptor agonists (GLP1RA), and dipeptidyl peptidase 4 inhibitors (DPP4i). Bilirubin is an antioxidant with fat-burning actions by binding to the PPARα nuclear receptor transcription factor, improving insulin sensitivity, reducing inflammation, and reversing metabolic dysfunction. Potential treatment with antioxidants like bilirubin and increasing the enzyme that produces it, heme oxygenase (HMOX), has also gained attention. This review discusses the relationships between bilirubin, HMOX, and insulin sensitivity, how T2DM medications affect HMOX levels and activity, and potentially using bilirubin nanoparticles to treat insulin resistance. We explore the sex differences between these treatments in the HMOX system and how bilirubin levels are affected. We discuss the emerging concept that bilirubin bioconversion to urobilin may have a role in metabolic diseases. This comprehensive review summarizes our understanding of bilirubin functioning as a hormone, discusses the HMOX isoforms and their beneficial mechanisms, analyzes the sex differences that might cause a dichotomy in responses, and examines the potential use of HMOX and bilirubin nanoparticle therapies in treating metabolic diseases.

Association of the triglyceride glucose index with all cause and CVD mortality in the adults with diabetes aged < 65 years without cardiovascular disease

Although the triglyceride-glucose (TyG) index has been established as a valuable predictor for cardiovascular disease (CVD) and cardiovascular mortality, there is limited research exploring its association with all-cause or CVD mortality specifically in adults with diabetes aged < 65 years without cardiovascular disease. This study aimed to investigate the relationship between the TyG index and both all-cause and CVD mortality in this population within the United States. Our study recruited 1778 adults with diabetes aged < 65 years without cardiovascular disease from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Mortality outcomes were determined by linking to National Death Index (NDI) records up to December 31, 2019. Cox regression modeling was employed to examine the association between the TyG index and mortality in this population. The nonlinear relationship between the TyG index and mortality was assessed using restricted cubic splines (RCS). Additionally, subgroup analyses and interaction tests were conducted to explore potential effect modifiers. A total of 1788 participants were included in the final cohort, with an average age of 49.61 ± 0.32 years. During a median follow-up of 7.92 years, the occurrence of 150 all-cause deaths and 33 CVD-related deaths were recorded. To investigate the independent association between the TyG index and the risks of all-cause and CVD mortality, three Cox regression models were developed. In Model 1, a significant positive association was observed between the TyG index and the risk of all-cause mortality (HR 1.38, 95% CI 1.09-1.74). This association persisted in the minimally adjusted model (HR 1.44, 95% CI 1.13-1.83), which was adjusted for age, gender and race. Even after full adjustment, this positive association remained significant (HR 1.91, 95% CI 1.36-2.70). We also found that the relationship between the TyG index and all-cause mortality was linear. Subgroup analyses revealed no significant interactions between the TyG index and the stratification variables. However, we did not observe a significant association between the TyG index and CVD mortality in this population. Our results suggested that a significantly positive association between the TyG index and all-cause mortality. The positive association between the TyG index and all-cause mortality was linear. We did not observe a significant association between the TyG index and CVD mortality.

Association between triglyceride/high density lipoprotein ratio and incidence risk of Parkinson's disease: a population-based cohort study

The association between insulin resistance and increased risk of Parkinson's disease (PD) has rarely been investigated. Our study aimed to investigate the association between the triglyceride/high-density lipoprotein (TG/HDL) ratio (which represents insulin resistance), and the incidence risk of PD in the general population. This study was conducted using data from the National Health Insurance Service-Health Screening Cohort Database of South Korea (2002-2019). We enrolled 310,023 participants who had no previous PD history and who had undergone more than three repeated measurements for the TG/HDL cholesterol ratio. The diagnosis of PD was determined using the International Classification of Diseases, 10th Revision code G20, specific reimbursement codes for Rare Intractable Diseases of V124, and a history of anti-PD drug prescription. During a median of 9.64 years (interquartile range 8.72-10.53), 4,587 individuals (1.47%) had an incidence of PD. Considering the multivariable time-dependent Cox proportional hazard model with repeated measures of average TG/HDL cholesterol ratio, a per unit increase in TG/HDL cholesterol ratio significantly increased the risk of PD in the entire cohort (hazard ratio (HR), 1.010; 95% confidence interval (CI), 1.001-1.020). These repeated measures of the average TG/HDL cholesterol ratio were associated with the incidence risk of PD in a J-shaped pattern for the entire diabetes mellitus (DM) and non-DM cohorts in restricted cubic spline analysis. Compared to the lowest tertiles (T1), the highest tertiles (T3) were positively associated with the incidence risk of PD (HR: 1.149, 95% CI 1.065-1.239 in the entire cohort, p for trend < 0.001; HR: 1.175, 95% CI 1.075-1.285 in the non-DM cohort, p for trend < 0.001). In contrast, the lowest (T1) and highest tertiles (T3) were not associated with the incidence risk of PD in the DM cohort (HR: 1.128, 95% CI 0.909-1.348) in fully adjusted multivariable analysis. Our study provides information that TG/HDL ratio may be positively associated with PD incidence risk in a non-DM population in longitudinal setting of the general population.

Association between the triglyceride/high-density lipoprotein (TG/HDL) ratio and incidence of gout: A nationwide cohort study

Introduction

The global burden of gout, a severe and painful arthralgia, is of note and is expected to increase in the future. We aimed to investigate the association between the triglyceride/high-density lipoprotein (TG/HDL) ratio, a simple and validated biomarker for insulin resistance, and the incidence of gout in a longitudinal setting in the general population.

Methods

Our study was conducted using the National Health Insurance Service-Health Screening Cohort database of Republic of Korea (2002-2019). We included 300,107 participants who had no previous history of gout and had data for more than three repeated measurements of the triglyceride-glucose (TyG) index. The incidence of gout was determined using at least two or more claims of the ICD-10 code M10.

Results

During a median 9.62 years (interquartile range 8.72-10.53), 14,116 individuals (4.72%) had a reported incidence of gout. In a fully adjusted multivariable time-dependent Cox proportional hazards model with repeated measures of the TyG index, a unit increase in the index significantly increased the risk of gout in the entire cohort (hazard ratio (HR) = 1.150, 95% confidence interval (CI) 1.116-1.184). In a multivariable Cox proportional model of average TyG index quartiles, comparison of the lowest (Q1) and highest quartiles (Q4) indicated a significant positive association with the incidence of gout (HR: 1.326, 95% CI: 1.260-1.397). This association was non-linear (J-shape) when assessing the entire cohort and the diabetes and non-diabetes cohorts.

Conclusion

Our study demonstrated that increased TyG index was associated with an incidence risk of gout in the general population. Additionally, this association was non-linear (J-shape) not only in the entire cohort, but also in diabetes mellitus and non-diabetes mellitus cohorts. The TyG index may be an important predictor of gout.

Prospective association between handgrip strength in childhood and the metabolic syndrome score and insulin resistance indices in adolescence: an analysis based on the Ewha Birth and Growth Study

OBJECTIVES

Low handgrip strength (HGS) in children and adolescents might be associated with the risk of metabolic syndrome (MetS) and insulin resistance. This study prospectively evaluated the association between HGS in childhood and MetS in adolescence.

METHODS

Based on data from the Ewha Birth and Growth Study, this study analyzed HGS at ages 7 to 9 and metabolic indices at ages 13 to 15. In total, 219 participants were analyzed. The risk of MetS was evaluated using the continuous metabolic syndrome score (cMetS), and insulin resistance was assessed using fasting blood insulin and homeostasis model assessment of insulin resistance (HOMA-IR). Relative HGS in childhood was determined by dividing HGS by body weight and categorized as sex-specific quartiles.

RESULTS

This study found an inverse association between relative HGS levels in childhood and MetS and insulin resistance in adolescence. For each 1-group increase in relative HGS quartiles, cMetS (standarard [Std] β=-0.64, p<0.01), HOMA-IR (Std β=-0.21, p<0.01), and fasting blood insulin (Std β=-0.21, p<0.01) all decreased on average. These associations remained significant even after adjusting for confounding factors.

CONCLUSIONS

Our study showed a prospective association between HGS in childhood and the risk of MetS and insulin resistance in adolescence. It provides significant epidemiological evidence, emphasizing the importance of efforts to increase muscle strength from a young age to mitigate the risk of MetS and insulin resistance in adolescence.

Brain Iron Deposition Alterations in Type 2 Diabetes Mellitus Patients With Mild Cognitive Impairment Based on Quantitative Susceptibility Mapping

BACKGROUND

Iron is one of the most important elements in brain that may has a direct impact on the stability of central nervous system. The current study devoted to explore the alterations of iron distribution across the whole brain in type 2 diabetes mellitus (T2DM) patients with mild cognitive impairment (MCI).

METHODS

The quantitative susceptibility mapping (QSM) technique was used to quantify the intracranial iron content of 74 T2DM patients with MCI and 86 T2DM patients with normal cognition (NC). The group comparison was performed by a voxel-based analysis. Then we evaluated the relationships between cognitive indicators and magnetic susceptibility value (MSV) measured by QSM of the significant brain areas, which were set as the regions of interest (ROIs). In addition, we analyzed the moderation effects of grey matter volume (GMV) of the related brain areas and several metabolic and cerebrovascular factors on the associations between MSV of ROIs and cognitive characteristics.

RESULTS

T2DM patients with MCI exhibited a lower MSV in the right middle temporal gyrus (MTG) compared to NC group. And in the MCI group, there were significantly negative correlations between MSV of the right MTG and several memory indexes. Furthermore, the moderation effects of GMV of the whole brain and the bilateral MTG on the relationship between MSV of the right MTG and scores of list recognition were significant.

CONCLUSIONS

T2DM patients with MCI had a temporary decreased iron content in the right MTG, which may partially compensate for cognitive impairment.

TRIAL REGISTRATION

The study was registered at Clinicaltrials.gov (NCT02738671).

Lack of Efficacy of Pomegranate Supplementation on Insulin Resistance and Sensitivity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The objective of this study is to assess the impact of pomegranate supplements on insulin resistance (IR) and insulin sensitivity through a systematic review and meta-analysis of randomized controlled trials (RCTs). Additionally, we aim to analyze the differences in efficacy among various pomegranate extracts and the sensitivity of different diseases to pomegranate supplementation. We conducted searches in PubMed, Embase, Web of Science, and Cochrane Library up to October 30, 2023, for relevant studies published in English. The treatment group required the intake of pomegranate extract for a minimum of 4 weeks, with no restrictions on the extract type. The control group received a placebo or a treatment excluding pomegranate extract. The primary outcome was homeostatic model assessment for insulin resistance (HOMA-IR) and fasting insulin (FI), and the secondary outcome was quantitative insulin sensitivity check index (QUICKI). RoB 2 was used to assess the risk of bias in the original studies. We pre-specified subgroup analyses based on types of intervention, intervention duration, health condition, and intervention dose. Sensitivity analysis was conducted to validate result stability, utilizing Begg's test and Egger's test for publication bias. Data synthesis and analysis were performed using Stata 15.1 software. This study included a total of 15 RCTs with 673 participants conducted in 7 countries. Risk of bias results indicated an overall low risk of bias of the articles. Participants included healthy individuals, overweight and obese individuals, non-alcoholic fatty liver disease (NAFLD) patients, type 2 diabetes (T2DM) patients, polycystic ovary syndrome (PCOS) patients, metabolic syndrome (MS) patients, and individuals with hyperlipidemia. Pomegranate extract variations included pomegranate juice (PJ), pomegranate seed oil (PSO) capsule, pomegranate/pomegranate peel (PP) extract capsule, and pomegranate peel-added bread. The control groups primarily received placebo treatments with varying dosage and frequency. No adverse reactions were reported in any of the studies. The summary results showed that compared to the control groups, pomegranate extract had no significant impact on improving HOMA-IR levels in participants (WMD = -0.03, 95%CI: -0.37 to 0.31, and p = 0.851) and FI (WMD = -0.03, 95%CI: -0.42 to 0.36, and p = 0.862). Additionally, there was no significant advantage of pomegranate extract on QUICKI changes in T2DM and PCOS patients (WMD = 0.00, 95%CI: 0.00 to 0.01, and p = 0.002). Subgroup analysis results indicated that pomegranate extract could improve HOMA-IR levels in PCOS patients (WMD = -0.42, 95%CI: -0.54 to -0.29, and p < 0.001) and FI levels in T2DM, PCOS, and NAFLD patients. Our results indicate that pomegranate extract only improves HOMA-IR and FI levels in PCOS patients and FI levels in T2DM and NAFLD patients. No significant difference has been found for HOMA-IR, FI, or QUICKI in other metabolic diseases. The current evidence suggests that we should interpret the value of pomegranate extract in regulating IR and sensitivity cautiously. In the future, there is a need for more rigorously designed RCTs to specifically evaluate the impact of pomegranate supplementation on insulin sensitivity in patients with NAFLD, PCOS, and T2DM.

Experimental cell models of insulin resistance: overview and appraisal

Insulin resistance, a key factor in the development of type 2 diabetes mellitus (T2DM), is defined as a defect in insulin-mediated control of glucose metabolism in tissues such as liver, fat and muscle. Insulin resistance is a driving force behind various metabolic diseases, such as T2DM, hyperlipidemia, hypertension, coronary heart disease and fatty liver. Therefore, improving insulin sensitivity can be considered as an effective strategy for the prevention and treatment of these complex metabolic diseases. Cell-based models are extensively employed for the study of pathological mechanisms and drug screening, particularly in relation to insulin resistance in T2DM. Currently, numerous methods are available for the establishment of in vitro insulin resistance models, a comprehensive review of these models is required and can serve as an excellent introduction or understanding for researchers undertaking studies in this filed. This review examines and discusses the primary methods for establishing and evaluating insulin resistance cell models. Furthermore, it highlights key issues and suggestions on cell selection, establishment, evaluation and drug screening of insulin resistance, thereby providing valuable references for the future research efforts.

Causal Association Between BMI and Polycystic Ovarian Syndrome: Bidirectional 2-Sample Mendelian Randomization Study

OBJECTIVE

This study aimed to explore the causal effect of body mass index (BMI) on polycystic ovarian syndrome (PCOS).

METHODS

Genome-wide association data for BMI and PCOS were sourced from the Mendelian randomization (MR) base platform. Significantly associated single nucleotide polymorphisms (SNPs) for BMI served as instrumental variables in bidirectional 2-sample MR analyses to investigate the causal relationship between BMI and PCOS. Analytical techniques utilized encompassed the inverse variance weighted (IVW) method, weighted median estimator, and MR-Egger regression.

RESULTS

We identified 427 SNPs significantly associated with BMI (P < 5 × 10-8; linkage disequilibrium r2 < 0.001). Various methods consistently revealed a positive association between BMI and PCOS (IVW: odds ratio [OR] 2.027 [95% CI 1.599-2.596]; weighted median estimator: OR 2.368 [95% CI 1.653-3.392]; MR-Egger method: OR 3.610 [95% CI 1.795-7.263]), indicating that higher BMI correlates with an increased risk of PCOS. Additionally, we observed a causal effect of genetic predisposition to PCOS on BMI (IVW: OR 1.020 [95% CI 1.019-1.022]; weighted median estimator: OR 1.017 [95% CI 1.015-1.019]; MR-Egger method: OR 1.000 [95% CI 0.995-1.005]).

CONCLUSION

The MR analysis furnished compelling evidence suggesting a causal relationship between elevated BMI and the risk of PCOS, as well as indicating that the severity of PCOS may contribute to elevated BMI levels.

The Role of Hypothalamic Microglia in the Onset of Insulin Resistance and Type 2 Diabetes: A Neuro-Immune Perspective

Historically, microglial activation has been associated with diseases of a neurodegenerative and neuroinflammatory nature. Some, like Alzheimer's disease, Parkinson's disease, and multiple system atrophy, have been explored extensively, while others pertaining to metabolism not so much. However, emerging evidence points to hypothalamic inflammation mediated by microglia as a driver of metabolic dysregulations, particularly insulin resistance and type 2 diabetes mellitus. Here, we explore this connection further and examine pathways that underlie this relationship, including the IKKβ/NF-κβ, IRS-1/PI3K/Akt, mTOR-S6 Kinase, JAK/STAT, and PPAR-γ signaling pathways. We also investigate the role of non-coding RNAs, namely microRNAs and long non-coding RNAs, in insulin resistance related to neuroinflammation and their diagnostic and therapeutic potential. Finally, we explore therapeutics further, searching for both pharmacological and non-pharmacological interventions that can help mitigate microglial activation.

Research progress on the role of extracellular vesicles in the pathogenesis of diabetic kidney disease

Diabetic kidney disease (DKD) is a serious complication of diabetes mellitus (DM) and has become the main cause of end-stage renal disease worldwide. In recent years, with the increasing incidence of DM, the pathogenesis of DKD has received increasing attention. The pathogenesis of DKD is diverse and complex. Extracellular vesicles (EVs) contain cell-derived membrane proteins, nucleic acids (such as DNA and RNA) and other important cellular components and are involved in intercellular information and substance transmission. In recent years, an increasing number of studies have confirmed that EVs play an important role in the development of DKD. The purpose of this paper is to explain the potential diagnostic value of EVs in DKD, analyze the mechanism by which EVs participate in intercellular communication, and explore whether EVs may become drug carriers for targeted therapy to provide a reference for promoting the implementation and application of exosome therapy strategies in clinical practice.

Correlation between triglyceride-glucose index and early neurological deterioration in patients with acute mild ischemic stroke

Objective

The Triglyceride-glucose Index (TyG) index is a dependable metric for assessing the degree of insulin resistance, serving as a standalone predictor of ischemic stroke risk, but its precise relationship with early neurological deterioration (END) remains incompletely expounded within the context of acute mild ischemic stroke patients. This research is to examine the correlation of the TyG index with END among patients experiencing acute mild ischemic stroke in China.

Methods

This retrospective analysis was conducted to systematically gather data regarding patients experiencing their maiden episode of acute mild ischemic stroke and hospitalized at the Neurology Department of Nanjing Meishan Hospital, located in Nanjing, Jiangsu Province, China, over the period extending from January 2020 to December 2022. The severity of stroke was determined through the utilization of the National Institutes of Health Stroke Scale (NIHSS) scores upon their admission. Demographic characteristics were collected, and measurements of fasting blood glucose, blood lipids, and glycosylated hemoglobin Alc levels were taken. END was defined as a one-point rise in the motor item function score on the NIHSS or a two-point increase in the overall score during the initial 72 h of hospitalization. For evaluating the correlation of the TyG index with END, a multivariate logistic regression analysis was carried out. To investigate whether there is a nonlinear relationship between the TyG index and END, smoothed curves were utilized.

Results

The study included 402 patients diagnosed with acute mild ischemic stroke, with a mean age of 66.15 ± 10.04 years. Within this population, 205 were males (51.00%) and 197 were females (49.00%). Among these patients, 107 (26.62%) experienced END within 72 h of admission. Patients who developed END showed higher levels of the TyG index in comparison to those who remained stable (9.18 ± 0.46 vs. 8.87 ± 0.46, p < 0.001). In a comprehensive multivariate logistic regression analysis, the TyG index positively correlates with END (OR = 3.63, 95% CI: 1.75-7.54, p = 0.001). Furthermore, individuals in the fourth TyG index quartile exhibited a 2.36-fold heightened risk of END compared to those in the first quartile (95% CI: 1.38-8.19, p = 0.008). TyG index has a linear correlation with END in the generalized additive model (Log likelihood ratio test, p = 0.525).

Conclusion

Our findings demonstrate that TyG index has a significant, independent, and positive correlation with END in Chinese individuals diagnosed with acute mild ischemic stroke. This underscores the TyG index's potential usefulness as a valuable risk stratification tool for stroke patients.

The impact of insulin resistance and glycaemic control on insulin-like growth factor-1 in patients with type 2 diabetes: a cross-sectional study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a multifaceted metabolic disorder. Over the past decade, the potential role of Growth Hormone (GH) and Insulin-like Growth Factor-1 (IGF-1) in the pathogenesis and progression of T2DM has garnered scientific interest. These hormones, while interrelated, exert differential effects on glucose homeostasis; GH elevates blood glucose levels, whereas IGF-1 sustains insulin secretion and augments insulin sensitivity.

OBJECTIVE

The study aimed to investigate the impact of insulin resistance and glycaemic control on IGF-1 levels and to assess other risk factors influencing IGF-1 in T2DM.

METHODS

A cross-sectional study was conducted at the National Diabetes Centre, Baghdad, Iraq, from May 2020 to May 2021. Sixty patients with T2DM were evaluated for fasting plasma glucose (FPG), GH, IGF-1, HbA1c, HOMA-IR, HOMA-B, and anthropometric measures following a comprehensive history and physical examination, focusing on any variables that could influence their metabolic profile. Patients with Type 1 diabetes mellitus, thyroid disease, pituitary disease, chronic kidney disease, hepatic disease, and pregnancy were excluded from the study.

RESULTS

Patients with poorly controlled diabetes (HbA1c > 8) exhibited significantly elevated IGF-1 levels compared to those with HbA1c < 8 (166 vs. 134, P = 0.016). The mean IGF-1 was significantly lower in patients with insulin resistance (IR) compared to those without IR (143 vs. 192, P = 0.001), with a significant negative correlation with Body Mass Index (BMI) and a significant positive correlation with HbA1c and Quantitative Insulin Sensitivity Index (QUICKI). Elevated IGF-1 levels were observed with increasing age, duration of T2DM, higher HbA1c, higher QUICKI, and lower BMI. No significant difference was found in IGF-1 values with regards to HOMA-B, fasting insulin, and waist-hip ratio.

CONCLUSION

Patients with poorly controlled T2DM exhibit higher IGF-1 levels, while those with obesity and high insulin resistance demonstrate lower IGF-1 levels. Further prospective studies are warranted to evaluate the potential of using IGF-1 to reduce insulin resistance and improve metabolic and glycaemic measures in individuals with T2DM and obesity or insulin resistance.

Magnesium Depletion Score and Metabolic Syndrome in US Adults: Analysis of NHANES 2003 to 2018

CONTEXT

The association between magnesium status and metabolic syndrome (MetS) remains unclear.

OBJECTIVE

This study aimed to examine the relationship between kidney reabsorption-related magnesium depletion score (MDS) and MetS among US adults.

METHODS

We analyzed data from 15 565 adults participating in the National Health and Nutrition Examination Survey (NHANES) 2003 to 2018. MetS was defined according to the National Cholesterol Education Program's Adult Treatment Panel III report. The MDS is a scoring system developed to predict the status of magnesium deficiency that fully considers the pathophysiological factors influencing the kidneys' reabsorption capability. Weighted univariate and multivariable logistic regression were used to assess the association between MDS and MetS. Restricted cubic spline (RCS) analysis was conducted to characterize dose-response relationships. Stratified analyses by sociodemographic and lifestyle factors were also performed.

RESULTS

In both univariate and multivariable analyses, higher MDS was significantly associated with increased odds of MetS. Each unit increase in MDS was associated with approximately a 30% higher risk for MetS, even after adjusting for confounding factors (odds ratio 1.31; 95% CI, 1.17-1.45). RCS graphs depicted a linear dose-response relationship across the MDS range. This positive correlation remained consistent across various population subgroups and exhibited no significant interaction by age, sex, race, adiposity, smoking status, or alcohol consumption.

CONCLUSION

Higher urinary magnesium loss as quantified by MDS may be an independent linear risk factor for MetS in US adults, irrespective of sociodemographic and behavioral factors. Optimizing magnesium nutritional status could potentially confer benefits to patients with MetS.

Association between different insulin resistance surrogates and osteoarthritis: a cross-sectional study from NHANES 1999-2018

BACKGROUND

Previous studies have demonstrated a relationship between prevalence of Osteoarthritis (OA) and insulin resistance (IR). The correlation between IR surrogates indices and gold standard tool for IR evaluation (Hyperinsulinemic-euglycemic clamp (HIEC)) have been well demonstrated. However, few studies evaluated the relationship between IR surrogates and OA. The aim of this study is to investigate the potential associations between different IR surrogates (the homeostatic model assessment of insulin resistance (HOMA-IR) index, the triglyceride glucose (TyG) index, the triglyceride glucose with body mass (TyG-BMI) index, the triglyceride glucose with waist circumference (TyG-WC) index, and the triglyceride glucose with the ratio of waist circumference divided by height (TyG-WtHR) index) and OA.

METHODS

This study used data from the National Health and Nutrition Examination Survey (NHANES). Multivariate logistic regression analysis was used to assess the associations of different IR surrogates with OA.

RESULTS

After adjusting for covariates, TyG-BMI index (OR = 1.006, 95% CI [1.004, 1.007], P < 0.0001), TyG-WC index (OR = 1.002, 95% CI [1.002, 1.003], P < 0.0001) and TyG-WtHR index (OR = 1.425, 95%CI [1.292,1.572], P < 0.0001) still showed robust positive correlation with IR. The risk of OA in the fourth quartile of the TyG-BMI index, TyG-WC index, and TyG-WtHR index are 2.634-fold, 2.651-fold, and 2.433-fold higher than that in the first quartile, respectively.

CONCLUSIONS

Compared to the HOMA-IR index and the TyG index, the association between the TyG-BMI, TyG-WC, and TyG-WtHR indices and OA is closer and more stable. The TyG-WtHR index has the highest accuracy in predicting OA, followed by the TyG-WC and TyG-BMI index.

Role of Peripheral and Central Insulin Resistance in Neuropsychiatric Disorders

Insulin acts on different organs, including the brain, which helps it regulate energy metabolism. Insulin signaling plays an important role in the function of different cell types. In this review, we have summarized the key roles of insulin and insulin receptors in healthy brains and in different brain disorders. Insulin signaling, as well as insulin resistance (IR), is a major contributor in the regulation of mood, behavior, and cognition. Recent evidence showed that both peripheral and central insulin resistance play a role in the pathophysiology, clinical presentation, and management of neuropsychiatric disorders like Cognitive Impairment/Dementia, Depression, and Schizophrenia. Many human studies point out Insulin Resistance/Metabolic Syndrome can increase the risk of dementia especially Alzheimer's dementia (AD). IR has been shown to play a role in AD development but also in its progression. This review article discusses the pathophysiological pathways and mechanisms of insulin resistance in major neuropsychiatric disorders. The extent of insulin resistance can be quantified using IR biomarkers like insulin levels, HOMA-IR index, and Triglyceride glucose-body mass index (TyG-BMI) levels. IR has been shown to precede neurodegeneration. Human trials showed current treatment with certain antidiabetic drugs, as well as life style management, like weight loss and exercise for IR, have shown promise in the management of cognitive/neuropsychiatric disorders. This may pave the pathway to the development of new therapeutic approaches to these challenging disorders of dementia and psychiatric diseases. Recent clinical trials are showing some encouraging evidence for these pharmacological and nonpharmacological approaches for IR in psychiatric and cognitive disorders, even though more research is needed to apply this evidence into clinical practice. Early identification and management of IR may help as a strategy to potentially alter neuropsychiatric disorders onset as well as its progression.

Melatonin regulates endoplasmic reticulum stress in diverse pathophysiological contexts: A comprehensive mechanistic review

The endoplasmic reticulum (ER) is crucial for protein quality control, and disruptions in its function can lead to various diseases. ER stress triggers an adaptive response called the unfolded protein response (UPR), which can either restore cellular homeostasis or induce cell death. Melatonin, a safe and multifunctional compound, shows promise in controlling ER stress and could be a valuable therapeutic agent for managing the UPR. By regulating ER and mitochondrial functions, melatonin helps maintain cellular homeostasis via reduction of oxidative stress, inflammation, and apoptosis. Melatonin can directly or indirectly interfere with ER-associated sensors and downstream targets of the UPR, impacting cell death, autophagy, inflammation, molecular repair, among others. Crucially, this review explores the mechanistic role of melatonin on ER stress in various diseases including liver damage, neurodegeneration, reproductive disorders, pulmonary disease, cardiomyopathy, insulin resistance, renal dysfunction, and cancer. Interestingly, while it alleviates the burden of ER stress in most pathological contexts, it can paradoxically stimulate ER stress in cancer cells, highlighting its intricate involvement in cellular homeostasis. With numerous successful studies using in vivo and in vitro models, the continuation of clinical trials is imperative to fully explore melatonin's therapeutic potential in these conditions.

Hepatokines: unveiling the molecular and cellular mechanisms connecting hepatic tissue to insulin resistance and inflammation

Insulin resistance arising from Non-Alcoholic Fatty Liver Disease (NAFLD) stands as a prevalent global ailment, a manifestation within societies stemming from individuals' suboptimal dietary habits and lifestyles. This form of insulin resistance emerges as a pivotal factor in the development of type 2 diabetes mellitus (T2DM). Emerging evidence underscores the significant role of hepatokines, as hepatic-secreted hormone-like entities, in the genesis of insulin resistance and eventual onset of type 2 diabetes. Hepatokines exert influence over extrahepatic metabolism regulation. Their principal functions encompass impacting adipocytes, pancreatic cells, muscles, and the brain, thereby playing a crucial role in shaping body metabolism through signaling to target tissues. This review explores the most important hepatokines, each with distinct influences. Our review shows that Fetuin-A promotes lipid-induced insulin resistance by acting as an endogenous ligand for Toll-like receptor 4 (TLR-4). FGF21 reduces inflammation in diabetes by blocking the nuclear translocation of nuclear factor-κB (NF-κB) in adipocytes and adipose tissue, while also improving glucose metabolism. ANGPTL6 enhances AMPK and insulin signaling in muscle, and suppresses gluconeogenesis. Follistatin can influence insulin resistance and inflammation by interacting with members of the TGF-β family. Adropin show a positive correlation with phosphoenolpyruvate carboxykinase 1 (PCK1), a key regulator of gluconeogenesis. This article delves into hepatokines' impact on NAFLD, inflammation, and T2DM, with a specific focus on insulin resistance. The aim is to comprehend the influence of these recently identified hormones on disease development and their underlying physiological and pathological mechanisms.

Prevalence of Clinical Manifestations Known to Be Associated With Insulin Resistance Among Female Medical Students of a Private College in Saudi Arabia

Background Insulin resistance has a significant relationship with a lot of chronic diseases. This is an alarm for the future high prevalence of many chronic diseases. Due to the lack of sufficient data surrounding the clinical manifestations of insulin resistance among the Saudi population, the study aims to fill this gap by assessing the prevalence of dermatological, cognitive, daytime sleep, and craving changes in the Saudi population, which are markers of insulin resistance. Methods A cross-sectional study was carried out to study the prevalence of clinical manifestations known to be associated with insulin resistance with a convenient nonprobability sample among 272 female medical students at the Ibn Sina National College for Medical Studies, a private medical college in Jeddah, Saudi Arabia. Each participant underwent an in-person interview where height, weight, and waist circumference were measured and BMI calculated. The in-person interview was performed using a series of questionnaires that assessed demographic data and clinical manifestations related to insulin resistance. Data was collected and grouped using Microsoft Excel (Microsoft Corp., Redmond, WA, USA). Statistical analyses were performed using IBM SPSS Statistics for Windows, version 22 (IBM Corp., Armonk, NY, USA). For prevalence calculations, percentages were used. The Chi-square test was used to analyze qualitative variables. The level of significance adopted was p < 0.05. Results The research revealed that acanthosis nigricans, skin tags, and alopecia areata were statistically significant in relation to waist circumference as an indicator of insulin resistance. Conversely, of all the dermatological manifestations, acne, psoriasis, hidradenitis suppurativa, hirsutism, and vitiligo were not associated with waist circumference. Also, polycystic ovary syndrome (PCOS) was statistically significant. Regards cognitive changes, carbohydrate craving, and day sleep were all proportionally higher in the high waist circumference category but were not found to be significantly significant in relation to waist circumference. Conclusion  The findings of the study confirm the association of dermatological and endocrine features such as acanthosis nigricans, skin tags, alopecia areata, and PCOS with waist circumference as an indicator of insulin resistance. The high prevalence of increased waist circumference in the study population is also in line with international data concerning the increasing incidence of insulin resistance and, consequently, diabetes mellitus will be seen among younger age groups.

Characterization and analysis of extracellular vesicle-derived miRNAs from different adipose tissues in mice

Adipose tissue is traditionally classified into two main types based on their functions: brown adipose tissue (BAT) and white adipose tissue (WAT). Each type plays a distinct role in the body's energy metabolism. Additionally, a third type, beige adipose tissue, can develop within subcutaneous WAT (including inguinal WAT, iWAT) in response to specific stimuli and exhibits characteristics of both BAT and WAT. Extracellular vesicles (EVs) are crucial for intercellular communication, carrying a diverse array of biomolecules such as proteins, lipids, and nucleic acids. While the functional diversity and endocrine roles of adipose tissues are well-documented, a comparative analysis of the functions of EVs released by different adipose tissues from mice housed at room temperature has not been thoroughly explored. MicroRNAs (miRNAs), which are highly enriched in small extracellular vesicles (sEVs), offer a promising avenue for investigating the complex functions and unique roles of various adipose tissues. In this study, we isolated sEVs from different adipose tissues under basal conditions and performed a comprehensive analysis of their miRNA content. By comparing miRNA profiles across different adipose tissues, we aim to elucidate the potential roles of sEV-derived miRNAs in mediating intercellular communication and the distinct physiological functions of adipose tissues. Understanding the molecular features of miRNAs in adipose tissue EVs could reveal new aspects of adipose tissue biology and lay the groundwork for further research into their physiological significance.