The contributions of fasting and postprandial blood glucose increments to oxidative stress and inflammation in dyslipidemic type 2 diabetic patients with stable ischemic heart disease

TEMR: Trans-ethnic mendelian randomization method using large-scale GWAS summary datasets

Available large-scale genome-wide association study (GWAS) summary datasets predominantly stem from European populations, while sample sizes for other ethnicities, notably Central/South Asian, East Asian, African, Hispanic, etc., remain comparatively limited, resulting in low precision of causal effect estimations within these ethnicities when using Mendelian randomization (MR). In this paper, we propose a trans-ethnic MR method, TEMR, to improve the statistical power and estimation precision of MR in a target population that is underrepresented, using trans-ethnic large-scale GWAS summary datasets. TEMR incorporates trans-ethnic genetic correlation coefficients through a conditional likelihood-based inference framework, producing calibrated p values with substantially improved MR power. In the simulation study, compared with other existing MR methods, TEMR exhibited superior precision and statistical power in causal effect estimation within the target populations. Finally, we applied TEMR to infer causal relationships between concentrations of 16 blood biomarkers and the risk of developing five diseases (hypertension, ischemic stroke, type 2 diabetes, schizophrenia, and major depression disorder) in East Asian, African, and Hispanic/Latino populations, leveraging biobank-scale GWAS summary data obtained from individuals of European descent. We found that the causal biomarkers were mostly validated by previous MR methods, and we also discovered 17 causal relationships that were not identified using previously published MR methods.

Predictive value of glucose coefficient of variation for in-hospital mortality in acute myocardial infarction patients undergoing PCI: Insights from the MIMIC-IV database

Background

Acute myocardial infarction (AMI) carries a high short-term risk of death, even after percutaneous coronary intervention (PCI). Glucose variability (GV), measured by the glucose coefficient of variation (GluCV), is a potential risk factor for adverse outcomes. This study investigates GluCV's predictive value for in-hospital mortality in AMI patients undergoing PCI.

Method

This study involved 2325 AMI patients who were admitted to the ICU and underwent PCI from the MIMIC-IV database. Patients were categorized into quartiles based on GluCV: <0.13, 0.13-0.20, 0.20-0.29, and ≥0.29. Multivariable logistic regression and Restricted cubic spline (RCS) analysis were employed to analyze the relationship between GluCV and in-hospital mortality. Mediation analysis was used to evaluate the role of GluCV in the relationship between disease complexity and severity.

Results

Among the 2325 patients, 203 (8.7 %) died during hospitalization. Higher GluCV was associated with increased in-hospital mortality. Adjusted odds ratios for mortality were 1.35 (95 % CI: 0.71-2.55), 1.91 (95 % CI: 1.04-3.51), and 3.32 (95 % CI: 1.83-6.02) for the second, third, and fourth groups, respectively. RCS analysis indicated a linear relationship between Log GluCV and mortality risk, with each 1 SD increase in Log GluCV associated with a 1.70-fold increase in mortality. Subgroup analysis showed a stronger relationship between GluCV and mortality in patients younger than 70. Mediation analysis indicated that GluCV partially mediates the effect of comorbidities on organ dysfunction.

Conclusions

GluCV is an important predictor of in-hospital mortality in AMI patients undergoing PCI. Managing GV to minimize fluctuations may improve patient prognosis.

Effect of fasting blood glucose on risk of new-onset hypertension in rural Chinese population: a 15-year follow-up cohort

BACKGROUND

The purpose of this study was to examine the correlation between fasting blood glucose and new-onset hypertension and examine any synergistically effect modification with multiple risk factors.

METHODS

We conducted post-hoc analyses of repeated-measures data in the original Dongzhi osteoporosis cohort study. In total, 3985 participants without hypertension aged 25-64 years were included in the current analyses. Generalized estimating equation models were used to assess the relationship between fasting blood glucose and risk of new-onset hypertension after adjusting for pertinent covariates and autocorrelations among siblings.

RESULTS

393 men (19.4%) and 398 women (20.3%) without hypertension at the baseline developed hypertension by the end of the study period. Compared to lower baseline fasting blood glucose levels (Q1-Q3: < 5.74 mmol/L; clinical cut points: < 5.6 mmol/L), higher baseline fasting blood glucose levels (Q4: ≥ 5.74 mmol/L; clinical cut points: ≥ 5.6 mmol/L and < 7.0 mmol/L) increased the risk of new-onset hypertension significantly [(OR: 1.54, 95% CI 1.19-1.98, P < 0.001); (OR: 1.38, 95% CI 1.09-1.75, P = 0.008)] in women. Additionally, a stronger significant association was found in women with elevated fasting blood glucose on risk of new-onset of hypertension with higher total cholesterol (≥ 5.2 mmol/L) [(OR: 2.76; 95% CI: (1.54, 4.96), P < 0.001)]. However, no association was found between fasting blood glucose and risk of new-onset hypertension in men.

CONCLUSIONS

High fasting blood glucose may be significantly associated with risk of new-onset hypertension in Chinese women, especially in women with higher total cholesterol. Further randomized studies are needed to confirm our findings.

The role of pioglitazone in antioxidant, anti-inflammatory, and insulin sensitivity in a high fat-carbohydrate diet-induced rat model of insulin resistance

We explored the cascade effects of a high fat-carbohydrate diet (HFCD) and pioglitazone (an anti-diabetic therapy used to treat type 2 diabetes mellitus (T2DM)) on lipid profiles, oxidative stress/antioxidant, insulin, and inflammatory biomarkers in a rat model of insulin resistance. Sixty albino rats (80-90 g) were randomly divided into three dietary groups; 1) standard diet; 2) HFCD diet for 12 weeks to induce an in vivo model of insulin resistance; and 3) HFCD diet plus pioglitazone. Blood and tissue samples were taken to assess hepatic function, lipid profiles, oxidative biomarkers, malondialdehyde (MDA) levels, antioxidant defense biomarkers, including reduced glutathione (GSH), superoxide dismutase (SOD), and the inflammatory markers interleukin-6 (IL-6) and tumor necrotic factor (TNF-α). HFCD-fed rats had significantly (P≤0.05) increased serum triacylglycerol (TG), total cholesterol (TC), low-density lipoprotein (LDL), alanine transaminase (ALT), and bilirubin levels, but decreased high-density lipoprotein (HDL) levels compared with the normal group. Moreover, serum leptin, resistin, TNF-α, and IL-6 levels were increased significantly in HFCD animals compared with controls. Similarly, HFCD-induced insulin resistance caused antioxidant and cytokine disturbances, which are important therapy targets for pioglitazone. Importantly, administration of this drug ameliorated these changes, normalized leptin and resistin and inflammatory markers by reducing TNF-α levels. Metabolic cascades of elevated lipid profiles, oxidative stress, insulin, and inflammatory biomarkers are implicated in insulin resistance progression. HFCD induced metabolic cascades comprising hypertriglyceridemia, hyperglycemia, insulin resistance, obesity-associated hormones, and inflammatory biomarkers may be alleviated using pioglitazone.

Efficacy of dulaglutide on vascular health indexes in subjects with type 2 diabetes: a randomized trial

Background

Recent cardiovascular outcome trials have shown significant reductions in major cardiovascular (CV) events with glucagon-like peptide (GLP)-1 receptor agonists. Additionally, adjunctive surrogates for cardiovascular risk validated by some studies include arterial stiffness and endothelial function indexes. To date, no randomized trial has addressed the possible effects of antidiabetic interventional drugs such as GLP1 agonists on endothelial and arterial stiffness indexes as surrogate markers of vascular damage.

Aims

We aimed to evaluate metabolic efficacy and surrogate vascular efficacy endpoints of once-weekly dulaglutide (1.5 mg) plus traditional antidiabetic treatment compared with traditional antidiabetic treatment alone in subjects with type 2 diabetes.

Methods

Men and women (aged ≥ 50 years) with established or newly detected type 2 diabetes whose HbA1c level was 9.5% or less on stable doses of up to two oral glucose­ lowering drugs with or without basal insulin therapy were eligible for randomization. Subcutaneous dulaglutide was initiated at the full dose (1.5 mg/day weekly). Arterial stiffness (PWV: pulse wave velocity and augmentation index) and endothelial function (RHI: reactive hyperaemia index) were evaluated at baseline and at three-month and nine-month examination visits. At each visit (at 3 and 9 months), the subjects were also evaluated for glycaemic variables such as fasting plasma glucose (FPG) and HbA1c and lipid variables such as total cholesterol, LDL cholesterol, HDL cholesterol and triglyceride levels.

Results

At the three-month follow-up, the subjects treated with dulaglutide showed significantly lower serum levels of FPG and HbA1c than control subjects treated with conventional therapy. At the 9-month follow-up, subjects treated with dulaglutide showed significant lower values of the mean diastolic blood pressure, BMI, total serum cholesterol, LDL cholesterol, FPG, HbA1c and PWV and higher mean RHI values than control subjects treated with conventional therapy.

Conclusions

Our randomized trial showed that subjects with type 2 diabetes treated with conventional therapy plus 1.5 mg/day of subcutaneous dulaglutide compared with subjects treated with conventional therapy alone showed favourable metabolic effects associated with positive effects on vascular health markers such as arterial stiffness and endothelial function markers. These findings are consistent with previous study findings indicating the strict relationship between cardiovascular risk factors such as systolic blood pressure, total serum cholesterol and LDL levels and cardiovascular events and vascular health surrogate markers.

LncRNA promoted inflammatory response in ischemic heart failure through regulation of miR-455-3p/TRAF6 axis

OBJECTIVES

Ischemic heart failure (IHF) is the most common cause of death globally. Growing evidence shows abnormal expression of long non-coding RNAs in heart failure patients. This study aims to investigate the effect of sex-determining region Y-box 2 (SOX2) overlapping transcript (SOX2-OT) on the regulation of the inflammatory response in ischemic heart failure.

METHODS

IHF rat and oxygen and glucose deprivation (OGD) cell models were established. qRT-PCR was employed to investigate the expression of SOX2-OT. ELISA, western blot and cell viability/apoptosis assays were performed to assess the effects of SOX2-OT. Online software program was used to identify miRNAs that target SOX2-OT, followed by validation using RNA pull-down. Potential targets of miRNAs were searched, and examined by immunoblotting, qRT-PCR and luciferase reporter assay.

RESULTS

SOX2-OT was up-regulated in IHF and OGD. Knockdown of SOX2-OT promoted cell proliferation, decreased apoptosis rate and cell oxidative damage, and ameliorated inflammatory response. SOX2-OT contains binding sites for miR-455-3p, miR-5586-3p and miR-1252-5p. RNA pull-down confirmed the binding ability between SOX2-OT and miR-455-3p. TRAF6 is a direct target of miR-455-3p. Moreover, the regulatory activity of SOX2-OT on inflammatory response was partially through its negative regulation of miR-455-3p, which directly regulates TRAF6. Down-regulation of SOX2-OT improved myocardial dysfunction in IHF rat.

CONCLUSIONS

Our results reveal that SOX2-OT may be a driver of IHF through repression of miR-455-3p, and miR-455-3p alleviates IHF by targeting TRAF6. Therefore, SOX2-OT/miR-455-3p/TRAF6 may be a potential target for advanced therapeutic strategy for IHF.

Fasting blood glucose is predictive of hypertension in a general Japanese population

OBJECTIVE

This study was conducted to identify whether higher fasting blood glucose levels is predictive of hypertension by a large-scale longitudinal design.

METHODS

We conducted a retrospective 5-year cohort study using the data from 13 201 Japanese individuals who underwent annual medical examinations in 2004 and were reevaluated 5 years later. This study included individuals without diabetes or hypertension between ages 30 and 85 years in 2004. The cumulative incidences of hypertension over 5 years in each 10 mg/dl of fasting blood glucose levels were calculated. Moreover, we examined risk factors and calculated odds ratios (ORs) for developing hypertension after adjustments for age, sex, BMI, smoking and drinking habits, dyslipidemia, chronic kidney disease, serum uric acid, and fasting blood glucose levels by logistic regression analyses.

RESULTS

We analyzed 10 157 participants (age: 48.9 ± 10.7 years; 43.4% men) without diabetes or hypertension in 2004. After multiple adjustments, higher baseline blood glucose level is an independent risk for hypertension (OR: 1.176; 95% CI 1.086-1.275), as well as aging, women, higher BMI, drinking habits, and higher serum uric acid. After stratifying by sex, higher baseline blood glucose level is an independent risk for hypertension both in women (OR: 1.295; 95% CI 1.135-1.478) and men (OR: 1.108; 95% CI 1.001-1.227). When we conducted the same analysis using glycated hemoglobin instead of blood glucose, glycated hemoglobin was not a risk for hypertension.

CONCLUSION

Higher fasting blood glucose is an independent risk for developing hypertension. Further studies are needed to determine if treatment for elevated blood glucose can prevent developing hypertension.

Differences in the association between glycemia and uric acid levels in diabetic and non-diabetic populations

AIMS

Our study aimed to investigate the influence of different glycemic statuses and their fasting plasma glucose/2-hour post-load glucose on uric acid level.

METHODS

A total of 14,787 subjects were recruited after excluding subjects with medication for hyperuricemia or diabetes. Fasting plasma glucose (FPG), 2-hour post-load glucose (2hPG), and uric acid (UA) were measured. Then, subjects were divided into normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes.

RESULTS

After adjustment for clinical variables, in NGT group, there was no significant relationship found between UA level and FPG. However, there was a positive association between UA level and 2hPG (β = 0.003, 95% CI: 0.002~0.004). A similar trend was also observed between UA level and 2hPG in IFG group (β = 0.004, 95% CI: 0.000~0.009) and IGT group (β = 0.005, 95% CI: 0.002~0.008), but relationship between UA level and FPG remained insignificant. In diabetes group, UA level was negatively associated with both FPG (β = -0.008, 95% CI: -0.010 ~ -0.007) and 2hPG (β = -0.005, 95% CI: -0.006 ~-0.003).

CONCLUSIONS

In non-diabetic individuals, UA level increased with 2hPG, but not with FPG, and UA level was inversely associated with both FPG and 2hPG in diabetic population.

A red orange and lemon by-products extract rich in anthocyanins inhibits the progression of diabetic nephropathy

The major cause of end-stage renal disease is the diabetic nephropathy. Oxidative stress contributes to the development of type II diabetes mellitus (T2DM). In this study we have evaluated the effect of a diet with a new standardized of red orange and lemon extract (RLE) rich in anthocyanins (ANT) in the progression of the kidney disease on Zucker diabetic fatty rats. Oxidative stress and renal function were analyzed. In diabetic rats, the RLE restored the blood glucose levels, body weight, and normalized the reactive oxygen species (ROS) total pathways. The kidney inflammation, in diabetic rats, has not shown significant change, showing that the oxidative stress rather than to inflammatory processes is a triggering factor in the renal complication associated with T2DM. Therefore, the administration of the RLE prevents this complication and this effect could be related to the inhibition of ROS production.

Circulating Oxidative Stress Biomarkers in Clinical Studies on Type 2 Diabetes and Its Complications

Type 2 diabetes (T2DM) and its complications constitute a major worldwide public health problem, with high rates of morbidity and mortality. Biomarkers for predicting the occurrence and development of the disease may therefore offer benefits in terms of early diagnosis and intervention. This review provides an overview of human studies on circulating biomarkers of oxidative stress and antioxidant defence systems and discusses their usefulness from a clinical perspective. Most case-control studies documented an increase in biomarkers of oxidative lipid, protein, and nucleic acid damage in patients with prediabetes and in those with a diagnosis of T2DM compared to controls, and similar findings were reported in T2DM with micro- and macrovascular complications compared to those without. The inconsistence of the results regarding antioxidant defence systems renders difficulty to draw a general conclusion. The clinical relevance of biomarkers of oxidative lipid and protein damage for T2DM progression is uncertain, but prospective studies suggest that markers of oxidative nucleic acid damage such as 8-hydroxy-2'-deoxyguanosine and 8-hydroxyguanosine are promising for predicting macrovascular complications of T2DM. Emerging evidence also points out the relationship between serum PON1 and serum HO1 in T2DM and its complications. Overall, enhanced oxidative damage represents an underlying mechanism of glucose toxicity in T2DM and its related micro- and macrovascular complications suggesting that it may be considered as a potential additional target for pharmacotherapy. Therefore, further studies are needed to understand whether targeting oxidative stress may yield clinical benefits. In this view, the measurement of oxidative stress biomarkers in clinical trials deserves to be considered as an additional tool to currently used parameters to facilitate a more individualized treatment of T2DM in terms of drug choice and patient selection.

Preoperative short-term fasting protects liver injury in patients undergoing hepatectomy

Background

Our previous study demonstrated that preoperative short-term fasting attenuates mice hepatic ischemia/reperfusion injury (IRI), which greatly piqued our interest in verifying if fasting produces similar protective effects in patients undergoing hepatectomy.

Methods

Eighty patients with liver tumors were randomized into control (Ctrl, n=40, preoperative fasting for 6 h) or fasting group (Fasting, n=40, preoperative fasting for 24 h). Serum was collected at pre-operation (Pre-Op), post-operation 1 day (POD-1), post-operation 3 days (POD-3), and post-operation 7 days (POD-7). Liver tissue was removed from the resected specimen.

Results

Sixty-three patients were eventually enrolled, with 33 in Ctrl and 30 in Fasting group. Our data showed that 24 h fasting effectively attenuated elevated sALT and sAST levels after operation (P<0.05), but serum total bilirubin was significantly lower at only POD-3 (P<0.05); and serum albumin was not markedly different in either of the groups. Interestingly, 24 h fasting partially attenuates expression of pro-inflammatory cytokine (TNF-α) and improves oxidative stress (MDA and SOD). Our data further showed short-term fasting triggered Nrf2 signaling pathway.

Conclusions

This study demonstrates preoperative short-term fasting effectively improves clinical outcomes and markedly attenuates inflammatory responses and oxidative stress in patients undergoing hepatectomy, and Nrf2 signaling pathway may play a key role in fasting against inflammatory responses and oxidant stress.

Effects of SGLT2 inhibitors on systemic and tissue low-grade inflammation: The potential contribution to diabetes complications and cardiovascular disease

Chronic low-grade inflammation is a recognized key feature associated with type 2 diabetes mellitus (T2DM) and its complications. In prospective randomized trials, sodium-glucose cotransporter type 2 (SGLT2) inhibitors have demonstrated benefits related to several cardiovascular and renal risk factors, including HbA_1c, blood pressure, body weight, renal hyperfiltration, and improvement of cardiorenal outcomes. SGLT2 inhibitors may improve adipose tissue function and induce decreases in serum leptin, TNF-α and IL-6 while increasing adiponectin. While data on high-sensitivity C-reactive protein and other inflammatory markers are relatively scarce in humans, in animals, a number of reports have shown reductions in cytokine and chemokine concentrations in parallel with protective effects against progression of atherosclerotic lesions. Experimental findings also suggest that part of the renoprotective effects of SGLT2 inhibition may be related to anti-inflammatory actions at the kidney level. Underlying mechanisms to explain this anti-inflammatory effect are multiple, but may involve weight loss, and reduction in adipose tissue inflammation, slight increase in ketone bodies and diminution of uric acid levels or attenuation of oxidative stress. However, further studies in diabetes patients with specific assessment of inflammatory markers are still necessary to determine the specific contribution of the anti-inflammatory action of SGLT2 inhibitors to the reduction of cardiovascular and renal complications and mortality observed with this class of antidiabetic drugs.