VLDL triglyceride accumulation in skeletal muscle and adipose tissue in type 2 diabetes

Endoplasmic reticulum stress and unfolded protein response in renal lipid metabolism

The endoplasmic reticulum (ER) is a crucial cellular organelle involved in protein synthesis, folding, modification, and transport. Exposure to internal and external stressors can induce endoplasmic reticulum stress (ERS), leading to abnormal protein folding and ER malfunction. This stress can disrupt lipid synthesis, metabolism, and transport processes. Fatty acid oxidation is the primary energy source for the renal system. When energy intake exceeds the storage capacity of adipose tissue, lipids accumulate abnormally in non-adipose tissues, including kidneys, liver, and pancreas. Lipids accumulate in the kidneys of nearly all cell types, including thylakoid membranous, pedunculated, and proximal renal tubular epithelial cells. Intracellular free fatty acids can significantly disrupt renal lipid metabolism, contributing to ischemia-reperfusion acute kidney injury, diabetic nephropathy, renal fibrosis, and lupus nephritis. Consequently, this study delineated the primary signaling pathways and mechanisms of the ERS-induced unfolded protein response, explored the mechanistic link between ERS and lipid metabolism, and elucidated its role in renal lipid metabolism. This study aimed to offer new perspectives on managing and treating renal disorders.

Assessing and predicting type 2 diabetes risk with triglyceride glucose-body mass index in the Chinese nondiabetic population-Data from long-term follow-up of Da Qing IGT and Diabetes Study

AIMS

We intended to characterize the superiority of triglyceride glucose-body mass index (TyG-BMI) in predicting type 2 diabetes mellitus (T2DM) compared with triglyceride glucose (TyG) and homeostatic model assessment for insulin resistance (HOMA-IR).

METHODS

A total of 699 nondiabetic participants in the Da Qing IGT and Diabetes Study were involved in the present analysis and classified according to the median of baseline TyG-BMI, namely the G1 (low TyG-BMI) and G2 (high TyG-BMI) groups. Information on developing diabetes was assessed from 1986 to 2020.

RESULTS

During the 34-year follow-up, after adjustment for confounders, the G2 group had a higher risk of developing type 2 diabetes than the G1 group (hazard ratio [HR]: 1.92, 95% confidence interval [CI]: 1.51-2.45, p < 0.0001). Restricted cubic spline analyses showed that increased TyG-BMI was linearly related to higher risks of type 2 diabetes (p for non-linearity>0.05). Time-dependent receiver operator characteristics curves suggested that TyG-BMI exhibited higher predictive ability than TyG (6-year: area under the curve [AUC]TyG-BMI vs. AUCTyG, 0.78 vs. 0.70, p = 0.03; 34-year: AUCTyG-BMI vs. AUCTyG, 0.79 vs. 0.73, p = 0.04) and HOMA-IR (6-year: AUCTyG-BMI vs. AUCHOMA-IR, 0.78 vs. 0.70, p = 0.07; 34-year: AUCTyG-BMI vs. AUCHOMA-IR, 0.79 vs. 0.71, p = 0.04) in both short and long terms, and the thresholds of TyG-BMI to predict type 2 diabetes were relatively stable (195.24-208.41) over the 34-year follow-up.

CONCLUSIONS

In this post hoc study, higher TyG-BMI was associated with an increased risk of type 2 diabetes and demonstrated better predictability than TyG and HOMA-IR, favoring the application of TyG-BMI as a potential tool for evaluating the risk of type 2 diabetes in clinical practice.

Association between Remnant Cholesterol and Metabolic Syndrome among Chinese Adults: Chinese Nutrition and Health Surveillance (2015-2017)

BACKGROUND

Remnant cholesterol (RC) is highly associated with several chronic diseases. However, the relationship between RC and Metabolic syndrome (MetS) remains unclear. The study's objective is to illustrate the relationship of RC to MetS.

METHODS

The data were collected from the Chinese Nutrition and Health Surveillance (2015-2017), which included personal, household and dietary information. A total of 65,618 residents aged 20 years or older from 31 provinces in mainland China were included in this study. RC was calculated by the equation RC = TC - (LDL-C + HDL-C). The criteria for MetS were based on the 2020 Chinese Type 2 Diabetes Prevention and Treatment Guidelines. Logistic regression models were used to analyse the relationship between RC and MetS and every MetS component. The receiver operating characteristic (ROC) curve was established to evaluate the accuracy of RC in identifying MetS, and the area under the curve (AUC) and the best threshold were calculated.

RESULTS

The weighted RC level of Chinese residents aged 20 years or older was 0.48 mmol/L. Participants with high RC levels were likely to be elderly, have a higher prevalence of MetS, higher total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FBG), hba1c, and lower high-density lipoprotein cholesterol (HDL-C). Sex, body mass index (BMI), education status, household yearly income per capita, marital status, area of the country, residence location, smoking status, fruit intake and sleep time had statistical differences in the RC group (p < 0.05). The OR of MetS gradually increased with an increase in the RC quartile (p < 0.01), and higher quartiles of RC (Q4) suggested the highest MetS risk. The prevalence of each MetS component gradually increased with an increase in the RC quartile. The ROC curve found that to identify MetS, the AUC and best threshold of RC were 0.71 and 0.52 mmol/L, respectively.

CONCLUSIONS

RC had a positive association with MetS and each MetS component. The accuracy in identifying MetS was higher in RC than in other indexes. The current study could provide new scientific evidence for the early prevention and control of MetS.

J-shaped association of the triglyceride glucose-body mass index with new-onset diabetes

The triglyceride glucose-body mass index (TyG-BMI) is a convenient and clinically significant indicator of insulin resistance. This study aims to investigate the correlation between TyG-BMI and the onset of new-onset diabetes and determine an optimal reflection point for TyG-BMI. An analysis was conducted on 1917 participants from the risk evaluation of cancers in Chinese diabetic individuals: a lONgitudinal (REACTION) study. Participants were categorized based on their TyG-BMI, and the relationship between TyG-BMI and the incidence of new-onset diabetes was explored through logistic regression models, smoothed curve fitting with restricted cubic spline, and a two-piecewise logistic regression model. The mean age of the participants was 57.60 ± 8.89 years, with 66.5% being females. The mean TyG-BMI was 223.3 ± 32.8. Ultimately, 137 individuals (7.1%) progressed to diabetes after three years. After adjusting for covariates, TyG-BMI exhibited a positive correlation with new-onset diabetes (odd ratios (OR) for each standard deviation increase = 1.330, 95% CI 1.110-1.595). The relationship between TyG-BMI and new-onset diabetes was non-linear, with a inflcetion point at 202.9. This study reveals a positive non-linear relationship between TyG-BMI and the risk of new-onset diabetes in Chinese middle-aged and elderly individuals. When TyG-BMI exceeds 202.9, there is a significantly heightened risk of new-onset diabetes. These findings offer valuable insights for preventing new-onset diabetes.

Unraveling the role of VLDL in the relationship between type 2 diabetes and coronary atherosclerosis: a Mendelian randomization analysis

Background

The causal link between Type 2 diabetes (T2D) and coronary atherosclerosis has been established through wet lab experiments; however, its analysis with Genome-wide association studies (GWAS) data remains unexplored. This study aims to validate this relationship using Mendelian randomization analysis and explore the potential mediation of VLDL in this mechanism.

Methods

Employing Mendelian randomization analysis, we investigated the causal connection between T2D and coronary atherosclerosis. We utilized GWAS summary statistics from European ancestry cohorts, comprising 23,363 coronary atherosclerosis patients and 195,429 controls, along with 32,469 T2D patients and 183,185 controls. VLDL levels, linked to SNPs, were considered as a potential mediating causal factor that might contribute to coronary atherosclerosis in the presence of T2D. We employed the inverse variance weighted (IVW), Egger regression (MR-Egger), weighted median, and weighted model methods for causal effect estimation. A leave-one-out sensitivity analysis was conducted to ensure robustness.

Results

Our Mendelian randomization analysis demonstrated a genetic association between T2D and an increased coronary atherosclerosis risk, with the IVW estimate at 1.13 [95% confidence interval (CI): 1.07-1.20]. Additionally, we observed a suggestive causal link between T2D and VLDL levels, as evidenced by the IVW estimate of 1.02 (95% CI: 0.98-1.07). Further supporting lipid involvement in coronary atherosclerosis pathogenesis, the IVW-Egger estimate was 1.30 (95% CI: 1.06-1.58).

Conclusion

In conclusion, this study highlights the autonomous contributions of T2D and VLDL levels to coronary atherosclerosis development. T2D is linked to a 13.35% elevated risk of coronary atherosclerosis, and within T2D patients, VLDL concentration rises by 2.49%. Notably, each standard deviation increase in VLDL raises the likelihood of heart disease by 29.6%. This underscores the significant role of lipid regulation, particularly VLDL, as a mediating pathway in coronary atherosclerosis progression.

Evaluation of the effects of metformin on antioxidant biomarkers and mineral levels in patients with type II diabetes mellitus: A cross-sectional study

Diabetes mellitus (DM) and arterial hypertension are considered serious public health problems. Several studies have shown that oxidative stress is usually related to the onset of DM and hypertension, as well their associated complications. Moreover, the levels of some minerals are closely related to the pathophysiology of these diseases. Thus, in this study we aimed to evaluate the effect of metformin on the redox profile and mineral levels in the serum of patients with DM type 2 and hypertension. We also tested the effect of metformin on the viability and redox profile of peripheral blood mononuclear cells (PBMCs) for 24 h. As expected, we found that patients with type 2 DM and hypertension + type 2 DM had higher fasting glucose and triglyceride levels. As groundbreaking research, we found that both patients DM type 2 and Hypertension + DM type 2 had reduced myeloperoxidase (MPO) activity. On the other hand, the levels of total thiols (PSH) and vitamin C were increased. There was no statistical significance for the alterations in mineral levels. In addition, metformin treatment had no cytotoxic effect on PBMCs. Similarly, in patients of both groups, MPO activity was reduced and PSH levels were increased in PBMCs. We have shown that metformin is a drug with a protective effect in patients with DM type 2 against oxidative stress by reducing MPO activity and improving the levels of PSH and antioxidant defenders such as vitamin C. The results of in vitro assays support the antioxidant effect of metformin. Furthermore, we suggest studies to assess the biochemical mechanisms of metformin and how it can be used in a pharmacological therapeutic perspective against oxidative damage.

Association of Serum Triglyceride and Stress Urinary Incontinence in Women From the National Health and Nutrition Examination Survey: A Cross-Sectional Study

OBJECTIVE

To investigate the relationship between serum triglyceride levels and stress urinary incontinence (SUI) in women from the National Health and Nutrition Examination Survey.

METHODS

Adults who participated in the National Health and Nutrition Examination Survey from 2005 to 2018 were included in the study. Univariate and multivariate logistic regressions were used to assess the relationship between serum triglyceride levels and the incidence and severity of SUI.

RESULTS

Approximately 7973 participants (mean, 49.9 years of age) were enrolled in the study. Of those, 3367 had SUI, and 4606 did not have SUI. An adjusted multivariate logistic regression analysis demonstrated a positive correlation between serum triglyceride levels and the incidence of SUI (ORs, 1.05; 95% CI, 1-1.11, P = .045). Besides, subgroup analyses indicated that the results were robust among women with different characteristics. Additionally, serum triglyceride levels were positively associated with the severity of SUI.

CONCLUSION

Serum triglyceride levels were closely related to the incidence and severity of SUI. Based on our findings, we suggest that serum triglycerides can be included as a risk indicator for screening high-risk groups of SUI.

Predictive Effect of Triglyceride Glucose-Related Parameters, Obesity Indices, and Lipid Ratios for Diabetes in a Chinese Population: A Prospective Cohort Study

Objective

The purpose of this study was to evaluate the association between triglyceride glucose (TyG) index and new-onset diabetes under different glycemic states and to compare the predictive value of TyG-related parameters, obesity indices, and lipid ratios for new-onset diabetes.

Methods

Data were collected from the China Health and Retirement Longitudinal Study (CHARLS), consisting of 6,258 participants aged ≥45 years. Participants were grouped according to their glycemic states. Cox proportional hazards models and restricted cubic spline regression were used to explore the association between TyG index and diabetes. Cox proportional hazard models were applied to confirm the predictive value of the optimal marker. Receiver operating characteristic (ROC) curves were used to compare the predictive value.

Results

TyG index was positively correlated with the risk of diabetes (hazard ratio (HR), 1.75; 95% confidence interval (CI), 1.56-1.97), and the linear association existed (p < 0.001). The highest correlation with diabetes was visceral adiposity index (VAI) (HR, 2.04; 95% CI, 1.44-2.90) in normal fasting glucose (NFG) group and TyG-body mass index (TyG-BMI) (HR, 2.53; 95% CI, 1.97-3.26) in impaired fasting glucose (IFG) group. The largest area under curve (AUC) was observed in TyG-waist-to-height ratio (TyG-WHtR) in the NFG group (AUC, 0.613; 95% CI, 0.527-0.700), and TyG-BMI had the highest AUC in the IFG group (AUC, 0.643; 95% CI, 0.601-0.685).

Conclusion

The association between TyG index and new-onset diabetes was positive and linear. TyG-WHtR was a clinically effective marker for identifying the risks of diabetes in the NFG group and TyG-BMI was an effective marker to predict diabetes in the IFG group.

The association between triglycerides and ectopic fat obesity: An inverted U-shaped curve

Background

Ectopic fat obesity and triglycerides are risk factors for diabetes and multiple cardiovascular diseases. However, there have been limited studies on the association between triglycerides and ectopic fat obesity. The purpose of this study was to explore the association between triglycerides and ectopic fat obesity.

Methods and results

In this cross-sectional study, we retrospectively analyzed 15464 adult participants recruited by Murakami Memorial Hospital (8430 men and 7034 women, average age of 43.71 ± 8.90). All patients were divided into two groups according to the threshold used to diagnose hypertriglyceridemia. The logistic regression model was used to analyze the association between triglycerides and the risk of ectopic fat obesity, and the generalized additive model was used to identify the nonlinear association. In this study population, the prevalence of ectopic fat obesity was 17.73%. After adjusting other covariables, triglycerides were positively correlated with the risk of ectopic fat obesity (OR: 1.54, 95% CI:1.41–1.69, P<0.0001). Through smooth curve fitting, we found that there was an inverted U-shaped curve association between triglycerides and ectopic fat obesity. This association remained unchanged even if the adjusted covariables were removed from the model, and the inflection point of the curve was 3.98. When triglyceride levels were ≤3.98, triglycerides were positively correlated with the risk of ectopic fat obesity (OR:1.784, 95% CI:1.611–1.975, P<0.0001). When triglyceride levels were >3.98 (right side of the inflection point), there was a negative correlation (OR:0.519, 95% CI:0.333–0.810, P = 0.0039).

Conclusions

Our research showed that there is a significant association between triglycerides and ectopic fat obesity. This relation is not a simple linear relationship but instead an inverted U-shaped curve association.