Low remnant cholesterol and the subsequent risk of new-onset atrial fibrillation: A prospective cohort study.

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia with high morbidity and mortality implications. Several studies have described a paradoxical inverse relationship between serum cholesterol and the risk of AF, but it remains unknown whether remnant cholesterol (RC) is associated with AF incidence. OBJECTIVE: This study aims to prospectively investigate the association between RC and AF. METHODS: A total of 392,783 participants free of AF at baseline from the UK Biobank were included for the analysis. Cox proportional hazards model, subgroup analysis, and sensitivity analyses were used to evaluate the independent association between RC levels and the risk of new-onset AF. Furthermore, we performed a discordance analysis by using the median cutoff points of low-density lipoprotein cholesterol (LDL-C) and RC. RESULTS: After a median follow-up of 12.8 years (interquartile range 12.0-13.6 years), a total of 23,558 participants experienced incident AF. Compared with the highest RC level, the lower RC level was associated with an increased risk of AF incidence (quartile 1 vs quartile 4: hazard ratio 1.396; 95% confidence interval [CI] 1.343-1.452). The results remained robust across a series of sensitivity analyses. In the discordance analyses, a significantly higher risk of AF was observed in participants with discordant low RC/high LDL-C levels than in those with concordant high RC/LDL-C levels. In the low LDL-C group, RC reduction even contributed to an additional 15.8% increased rate of incident AF (low RC/low LDL-C: hazard ratio 1.303; 95% CI 1.260-1.348 vs high RC/low LDL-C: hazard ratio 1.125; 95% CI 1.079-1.172). CONCLUSION: Low RC levels were associated with an increased risk of incident AF independent of traditional cardiovascular risk factors.

Sleep Patterns and Traditional Cardiovascular Health Metrics: Joint Impact on Major Adverse Cardiovascular Events in a Prospective Cohort Study.

BACKGROUND: This study examines the association between traditional cardiovascular health (CVH) metrics and major adverse cardiovascular events (MACE) incidence in individuals with diverse sleep patterns. METHODS AND RESULTS: We analyzed data from 208 621 participants initially free of cardiovascular disease (CVD) in the UK Biobank study. Sleep patterns were assessed using scores for chronotype, duration, insomnia, snoring, and daytime dozing. Traditional CVH scores were derived from the Life's Simple 7 metrics. Cox proportional hazards multivariate regression assessed associations between distinct combinations of CVH and sleep scores and MACE, including nonfatal myocardial infarction, nonfatal stroke, and CVD mortality. Over a mean follow-up of 12.73 years, 9253 participants experienced incident MACE. Individuals with both a healthy sleep pattern and ideal CVH levels had the lowest MACE risk compared with those with a poor sleep pattern and poor CVH levels (hazard ratio, 0.306 [95% CI, 0.257-0.365]; P<0.001). Elevated CVH scores were associated with a reduced risk of MACE across different sleep patterns. Similar trends were observed for individual MACE components, heart failure, and all-cause mortality. These findings remained robust in sensitivity analyses and across various subgroups. CONCLUSIONS: In individuals without known CVD, maintaining a favorable sleep pattern and achieving optimal CVH levels, as measured by traditional metrics, were associated with the lowest MACE risk. Enhanced CVH significantly reduced CVD risk, even in individuals with a poor sleep pattern. These results emphasize the importance of considering multiple dimensions of sleep health alongside CVH to mitigate CVD risk. REGISTRATION: URL: https://www.ukbiobank.ac.uk; Unique identifier: 91090.

SIRT3 suppression resulting from the enhanced ß-catenin signaling drives glycolysis and promotes hypoxia-induced cell growth in hepatocellular carcinoma cells.

The precise mechanisms underlying the inhibitory effects of SIRT3, a mitochondrial sirtuin protein, on hepatocellular carcinoma (HCC) development, as well as its impact on mitochondrial respiration, remain poorly understood. We assessed sirtuins 3 (SIRT3) levels in HCC tissues and Huh7 cells cultured under hypoxic condition. We investigated the effects of SIRT3 on cell proliferation, glycolytic metabolism, mitochondrial respiration, mitophagy, and mitochondrial biogenesis in Huh7 cells. Besides, we explored the potential mechanisms regulating SIRT3 expression in hypoxically cultured Huh7 cells. Gradual reduction in SIRT3 expressions were observed in both adjacent tumor tissues and tumor tissues. Similarly, SIRT3 expressions were diminished in Huh7 cells cultured under hypoxic condition. Forced expression of SIRT3 attenuated the growth of hypoxically cultured Huh7 cells. SIRT3 overexpression led to a decrease in extracellular acidification rate while increasing oxygen consumption rate. SIRT3 downregulated the levels of hexokinase 2 and pyruvate kinase M2. Moreover, SIRT3 enhanced mitophagy signaling, as indicated by mtKeima, and upregulated key proteins involved in various mitophagic pathways while reducing intracellular reactive oxygen species levels. Furthermore, SIRT3 increased proxisome proliferator-activated receptor-gamma coactivator 1α levels and the amount of mitochondrial DNA in Huh7 cells. Notably, ß-catenin expressions were elevated in Huh7 cells cultured under hypoxic condition. Antagonists and agonists of ß-catenin respectively upregulated and downregulated SIRT3 expressions in hypoxically cultured Huh7 cells. The modulationsof glycolysis and mitochondrial respiration represent the primary mechanism through which SIRT3, suppressed by ß-catenin, inhibits HCC cell proliferation.

Dietary vitamin C and vitamin E with the risk of aortic aneurysm and dissection: A prospective population-based cohort study.

BACKGROUND AND AIMS: The associations between dietary vitamin C (VC), vitamin E (VE) intake and aortic aneurysm and dissection (AAD) remain unclear. This study aimed to prospectively investigate the associations between dietary VC and VE with the incident risk of AAD. METHODS AND RESULTS: A total of 139 477 participants of UK Biobank cohort were included in the analysis. Dietary VC and VE consumptions were acquired through a 24-h recall questionnaire. Cox proportional regression models were used to examine the associations between VC, VE intake and the risk of AAD. Incident AAD was ascertained through hospital inpatient records and death registers. During a median follow-up of 12.5 years, 962 incident AAD events were documented. Both dietary VC [adjusted hazard ratio (HR), 0.77; 95 % confidence intervals (CI), 0.63-0.93; P-trend = 0.008] and VE (adjusted HR, 0.70; 95 % CI, 0.57-0.87; P-trend = 0.002) were inversely associated with incident AAD when comparing the participants in the highest quartile with those in the lowest. In subgroup analyses, the associations were more pronounced in participants who were over 60 years old, participants with smoking history, hypertension or hyperlipidemia, who were under the high risk of AAD. CONCLUSION: Higher dietary VC and VE intakes are associated with reduced risk of AAD. Our study emphasizes the importance of diet adjustment strategies targeted on VC and VE to lower the incidence rate of AAD especially in the high-risk population.

The association between tinnitus and risk of cardiovascular events and all-cause mortality: insight from the UK Biobank.

BACKGROUND: The potential influence of tinnitus on cardiovascular disease (CVD) and all-cause mortality has yet to be explored. We aim to examine the correlations between tinnitus and the risk of cardiovascular events and all-cause mortality. METHODS: We conducted a prospective cohort study utilising data from the UK Biobank. The presence of tinnitus was evaluated through a questionnaire. The primary outcome was defined as a composition of cardiovascular events, including myocardial infarction (MI), stroke, and mortality from CVD, as well as all-cause mortality. Cox proportional hazard models were employed to examine the associations between tinnitus and both the primary outcome and its individual components. Sensitivity analyses were conducted to evaluate the robustness of the primary analysis. RESULTS: A total of 140,146 participants were included in the study. The presence of tinnitus was found to be associated with a higher incident rate of the primary outcome (HR = 1.057, 95%CI: 1.017-1.099, p = 0.005), MI (HR = 1.139, 95%CI: 1.061-1.222, p < 0.001) and all-cause mortality (HR = 1.053, 95%CI: 1.003-1.105, p = 0.038) after adjusting for confounders. However, there was no significant association between tinnitus and stroke or mortality from CVD. Subgroup analysis revealed that the association between tinnitus and the primary outcome was significant in females, participants with abnormal BMI, and those without hearing difficulty, depression or anxiety. Sensitivity analyses yielded consistent results. CONCLUSION: The findings from this study contribute to the existing body of evidence suggesting an association between tinnitus and an increased risk of cardiovascular events and all-cause mortality.

Association between daytime napping and incident arrhythmias: A prospective cohort study and mendelian randomization analysis.

BACKGROUND: Emerging evidence has linked daytime napping with the risk of cardiovascular events. Cardiac arrhythmias are considered an early clinical stage for cardiovascular diseases. However, whether napping frequency is associated with incident arrhythmias remains unknown. OBJECTIVE: This study aimed to prospectively investigate the association between napping frequency and cardiac arrhythmias. METHODS: Daytime napping frequency was self-reported in response to touchscreen questionnaires. The primary outcomes were incident arrhythmias including atrial fibrillation/flutter (AF/Af), ventricular arrhythmia, and bradyarrhythmia. Cox regression analysis was conducted on the basis of 491,117 participants free of cardiac arrhythmias from the UK Biobank. The 2-sample mendelian randomization (MR) and 1-sample MR were used to ensure a causal effect of genetically predicted daytime napping on the risk of arrhythmias. RESULTS: During a median follow-up of 11.91 years, 28,801 incident AF/Af cases, 4132 incident ventricular arrhythmias, and 11,616 incident bradyarrhythmias were documented. Compared with never/rarely napping, usually napping was significantly associated with higher risks of AF/Af (hazard ratio, 1.141; 95% CI, 1.083-1.203) and bradyarrhythmia (hazard ratio, 1.138; 95% CI, 1.049-1.235) but not ventricular arrhythmia after adjustment for various covariates. The 2-sample MR and 1-sample MR analysis showed that increased daytime napping frequency was likely to be a potential causal risk factor for AF/Af in FinnGen (odds ratio, 1.626; 95% CI, 1.061-2.943) and bradyarrhythmia in the UK Biobank (odds ratio, 1.005; 95% CI, 1.002-1.008). CONCLUSION: The results of this study add to the burgeoning evidence of an association between daytime napping frequency and an increased risk of cardiac arrhythmias including AF/Af, ventricular arrhythmia, and bradyarrhythmia.

Remnant cholesterol and risk of incident hypertension: a population-based prospective cohort study.

Remnant cholesterol (RC) has been associated with atherosclerotic cardiovascular disease, but its relationship with hypertension remains unclear. This prospective cohort study aimed to investigate the association between RC and subsequent hypertension risk. Data from the UK Biobank, comprising 295,062 participants initially free of hypertension, were analyzed. Cox proportional hazards regression assessed the association between RC quartiles and hypertension risk. Discordance analysis evaluated the risk of hypertension in discordant/concordant groups of RC and low-density lipoprotein cholesterol (LDL-C) using the difference in percentile units (>10 units). Restricted cubic spline curves were used to model the relationship between RC and hypertension risk. The mean ± SD age of participants was 55.1 ± 8.1 years, with 40.6% being men and 94.7% White. During a median follow-up of 12.8 years, 39,038 participants developed hypertension. Comparing extreme quartiles of RC, the hazard ratio (HR) for incident hypertension was 1.20 (95% CI: 1.17-1.24). After adjusting for traditional risk factors, each 1 mmol/L increase in RC levels was associated with a 27% higher risk of incident hypertension (HR: 1.27; 95% CI: 1.23-1.31). The discordant group with high RC/low LDL-C exhibited a higher risk of incident hypertension compared to the concordant group (HR: 1.06; 95% CI: 1.03-1.09). Spline curves further demonstrated a positive association between RC and the risk of incident hypertension. We concluded that elevated RC emerged as an independent risk factor of incident hypertension, extending beyond traditional risk factors. Monitoring RC levels and implementing interventions to lower RC may have potential benefits in preventing hypertension.

Serum albumin and risk of incident diabetes and diabetic microvascular complications in the UK Biobank cohort.

AIM: To examine the associations between serum albumin and the incidences of diabetes and diabetic microvascular complications in participants of the UK Biobank cohort. METHODS: There were 398,146 participants without diabetes and 30,952 patients with diabetes from the UK Biobank cohort included in this study. Multivariate-adjusted Cox proportional hazard models were used to analyze the association of albumin with the incidences of diabetes and diabetic microvascular complications. Mendelian randomization (MR) analysis was used to determine the genetic relationships between serum albumin and diabetes. RESULTS: After a median 12.90 years follow-up, 14,710 participants developed incident diabetes (58.83 ± 7.52 years, 56.10% male). After multivariate adjustment, serum albumin was inversely associated with incident diabetes: hazard ratio (HR) [95% confidence interval] per 10 g/l increase 0.88 [0.82;0.94]. MR analyses suggested a potential genetic influence of serum albumin on diabetes in both the UK Biobank and the FinnGen consortium: odds ratios (ORs) [95% confidence interval per 1 g/l increase 0.99 [0.98;1.00] and 0.78 [0.67;0.92], respectively. In patients with diabetes, higher serum albumin levels were significantly associated with lower risk for diabetic microvascular complications. Specifically, per 10 g/l increase in serum albumin, the HRs for diabetic nephropathy, ophthalmopathy, and neuropathy were 0.42 [0.30;0.58], 0.61 [0.52;0.72], and 0.67 [0.51;0.88], respectively. CONCLUSION: In this large prospective study, serum levels of albumin were inversely associated with the incidences of diabetes and diabetic microvascular complications. These findings underscore the importance of maintaining optimal nutrient status in reducing the risk of diabetes and its complications.

Glycolysis Inhibition Alleviates Cardiac Fibrosis After Myocardial Infarction by Suppressing Cardiac Fibroblast Activation.

Objective: To explore the role of glycolysis in cardiac fibroblast (CF) activation and cardiac fibrosis after myocardial infarction (MI). Method: In vivo: 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor, was injected into the abdominal cavity of the MI or sham mice every day. On the 28th day, cardiac function was measured by ultrasonic cardiography, and the hearts were harvested. Masson staining and immunofluorescence (IF) were used to evaluate the fibrosis area, and western blot was used to identify the glycolytic level. In vitro, we isolated the CF from the sham, MI and MI with 2-DG treatment mice, and we also activated normal CF with transforming growth factor-ß1 (TGF-ß1) and block glycolysis with 2-DG. We then detected the glycolytic proteins, fibrotic proteins, and the concentrations of lactate and glucose in the culture medium. At last, we further detected the fibrotic and glycolytic markers in human fibrotic and non-fibrotic heart tissues with masson staining, IF and western blot. Result: More collagen and glycolytic protein expressions were observed in the MI mice hearts. The mortality increased when mice were treated with 2-DG (100 mg/kg/d) after the MI surgery (Log-rank test, P < 0.05). When the dosage of 2-DG declined to 50 mg/kg/d, and the treatment was started on the 4th day after MI, no statistical difference of mortality between the two groups was observed (Log-rank test, P = 0.98). The collagen volume fraction was smaller and the fluorescence signal of α-smooth muscle actin (α-SMA) was weaker in mice treated with 2-DG than PBS. In vitro, 2-DG could significantly inhibit the increased expression of both the glycolytic and fibrotic proteins in the activated CF. Conclusion: Cardiac fibrosis is along with the enhancement of CF activation and glycolysis. Glycolysis inhibition can alleviate cardiac fibroblast activation and cardiac fibrosis after myocardial infarction.

Long non-coding RNA Linc00092 inhibits cardiac fibroblast activation by altering glycolysis in an ERK-dependent manner.

AIMS: Cardiac fibroblast (CF) activation is the key event for cardiac fibrosis. The role of glycolysis and the glycolysis-related lncRNAs in CF activation are unknown. Thus, we aimed to investigate the role of glycolysis in CF activation and to identify the glycolysis-related lncRNAs involved. MAIN METHODS: Glycolysis-related lncRNAs were searched and their expression profiles were validated in activated human CF (HCF) and human failing heart tissues. Expression of the target lncRNA was manipulated to determine its effects on HCF activation and glycolysis. The underlying mechanisms of lncRNA-dependent glycolysis regulation were also addressed. KEY FINDINGS: HCF activation induced by transforming growth factor-ß1 was accompanied by an enhanced glycolysis, and 2-Deoxy-d-glucose, a specific glycolysis inhibitor, dramatically attenuated HCF activation. Twenty-eight glycolysis-related lncRNAs were identified and Linc00092 expression was changed mostly upon HCF activation. In human heart tissue, Linc00092 is primarily expressed in cardiac fibroblasts. Linc00092 knockdown activated HCFs with enhanced glycolysis, while its overexpression rescued the activated phenotype of HCFs and down-regulated glycolysis. Restoration of glycolysis abolished the anti-fibrotic effects conferred by Linc00092. Linc00092 inhibited ERK activation in activated HCFs, and ERK inhibition counteracted the fibrotic phenotype in Linc00092 knockdown HCFs. SIGNIFICANCE: These results revealed that Linc00092 could attenuate HCF activation by suppressing glycolysis. The inhibition of ERK by Linc00092 may play an important role in this process. Together, this provides a better understanding of the mechanism of CF activation and may serve as a novel target for cardiac fibrosis treatment.

Mitochondrial Fission and Mitophagy Reciprocally Orchestrate Cardiac Fibroblasts Activation.

Although mitochondrial fission has been reported to increase proliferative capacity and collagen production, it can also contribute to mitochondrial impairment, which is detrimental to cell survival. The aim of the present study was to investigate the role of mitochondrial fission in cardiac fibroblasts (CF) activation and explore the mechanisms involved in the maintenance of mitochondrial health under this condition. For this, changes in the levels of mitochondrial fission/fusion-related proteins were assessed in transforming growth factor beta 1 (TGF-ß1)-activated CF, whereas the role of mitochondrial fission during this process was also elucidated, as were the underlying mechanisms. The interaction between mitochondrial fission and mitophagy, the main defense mechanism against mitochondrial impairment, was also explored. The results showed that the mitochondria in TGF-ß1-treated CF were noticeably more fragmented than those of controls. The expression of several mitochondrial fission-related proteins was markedly upregulated, and the levels of fusion-related proteins were also altered, but to a lesser extent. Inhibiting mitochondrial fission resulted in a marked attenuation of TGF-ß1-induced CF activation. The TGF-ß1-induced increase in glycolysis was greatly suppressed in the presence of a mitochondrial inhibitor, whereas a glycolysis-specific antagonist exerted little additional antifibrotic effects. TGF-ß1 treatment increased cellular levels of reactive oxygen species (ROS) and triggered mitophagy, but this effect was reversed following the application of ROS scavengers. For the signals mediating mitophagy, the expression of Pink1, but not Bnip3l/Nix or Fundc1, exhibited the most significant changes, which could be counteracted by treatment with a mitochondrial fission inhibitor. Pink1 knockdown suppressed CF activation and mitochondrial fission, which was accompanied by increased CF apoptosis. In conclusion, mitochondrial fission resulted in increased glycolysis and played a crucial role in CF activation. Moreover, mitochondrial fission promoted reactive oxygen species (ROS) production, leading to mitophagy and the consequent degradation of the impaired mitochondria, thus promoting CF survival and maintaining their activation.

Construction and Analysis of a ceRNA Network in Cardiac Fibroblast During Fibrosis Based on in vivo and in vitro Data.

AIMS: Activation of cardiac fibroblasts (CF) is crucial to cardiac fibrosis. We constructed a cardiac fibroblast-related competing endogenous RNA (ceRNA) network. Potential functions related to fibrosis of "hub genes" in this ceRNA network were explored. MATERIALS AND METHODS: The Gene Expression Omnibus database was searched for eligible datasets. Differentially expressed messenger (m)RNA (DE-mRNA) and long non-coding (lnc)RNA (DE-lncRNA) were identified. microRNA was predicted and validated. A predicted ceRNA network was constructed and visualized by Cytoscape, and ceRNA crosstalk was validated. A Single Gene Set Enrichment Analysis (SGSEA) was done, and the Comparative Toxicogenomics Database (CTD) was employed to analyze the most closely associated pathways and diseases of DE-mRNA in the ceRNA network. The functions of DE-mRNA and DE-lncRNA in the ceRNA network were validated by small interfering (si)RNA depletion. RESULTS: The GSE97358 and GSE116250 datasets (which described differentially expressed genes in human cardiac fibroblasts and failing ventricles, respectively) were used for analyses. Four-hundred-and-twenty DE-mRNA and 39 DE-lncRNA, and 369 DE-mRNA and 93 DE-lncRNA were identified, respectively, in the GSE97358 and GSE116250 datasets. Most of the genes were related to signal transduction, cytokine activity, and cell proliferation. Thirteen DE-mRNA with the same expression tendency were overlapped in the two datasets. Twenty-three candidate microRNAs were predicted and the expression of 11 were different. Only two DE-lncRNA were paired to any one of 11 microRNA. Finally, two mRNA [ADAM metallopeptidase domain 19, (ADAM19) and transforming growth factor beta induced, (TGFBI)], three microRNA (miR-9-5p, miR-124-3p, and miR-153-3p) and two lncRNA (LINC00511 and SNHG15) constituted our ceRNA network. siRNA against LINC00511 increased miR-124-3p and miR-9-5p expression, and decreased ADAM19 and TGFBI expression, whereas siRNA against SNHG15 increased miR-153-3p and decreased ADAM19 expression. ADAM19 and TGFBI were closely related to the TGF-ß1 pathway and cardiac fibrosis, as shown by SGSEA and CTD, respectively. Depletion of two mRNA or two lncRNA could alleviate CF activation. CONCLUSIONS: The CF-specific ceRNA network, including two lncRNA, three miRNA, and two mRNA, played a crucial role during cardiac fibrosis, which provided potential target genes in this field.