Genetically Determined Inflammatory Biomarkers and the Risk of Heart Failure: A Mendelian Randomization Study

Causal relationship between chronic obstructive pulmonary disease and heart failure: A Mendelian randomization study

BACKGROUND

Causal association between chronic obstructive pulmonary disease (COPD) and heart failure (HF) has been controversial. This study used Mendelian Randomization (MR) analysis to clarify the potential causal connection between these two conditions.

OBJECTIVES

The purpose of the study was to investigate the causal relationship between COPD and HF based on the hypothesis that the genetic predisposition to COPD could lead to an increased risk of developing HF METHODS: A two-sample MR analysis of genetic data was performed for COPD and HF. This study was based on genome-wide association study (GWAS) data, including 6,915 patients with confirmed COPD and 186,723 controls. The odds ratios (ORs) and their 95 % confidence intervals (95 %CIs) were estimated using a fixed effects inverse variance weighting (IVW) method. Several supplementary statistical methods, including MR-Egger, weighted median, maximum likelihood, penalized weighted median, and random effects IVW, were applied to enhance the robustness of findings. Moreover, MR-PRESSO was employed as an alternative method for statistical detection.

RESULTS

Pooled data for HF were obtained from different GWASs, including 4,7309 confirmed HF patients and 930,014 controls. The MR analysis, based on the IVW model, revealed that COPD was significantly associated with an increased risk of HF. Specifically, the obtained findings showed that COPD patients had a higher risk of developing HF (Model 1: OR = 1.068, 95 %CI: 1.006-1.134, p = 0.031; Model 2: OR = 1.038, 95 %CI: 1.006-1.071, p = 0.020), indicating a causal relationship between COPD and HF. No evidence was found to suggest a reverse causal effect of HF on COPD incidence.

CONCLUSION

The MR analysis substantiates a causal link between COPD and HF, with no evidence supporting a reverse causation from HF to COPD. These findings underscore the importance of proactive COPD management as a potential strategy to prevent the development of HF, highlighting the need for targeted interventions in patients with COPD to mitigate their risk of HF.

Increased interleukin-6 is associated with higher risk of heart failure in people with type 2 diabetes

AIMS

We aimed to determine the association between serum interleukin-6 (IL-6) concentrations and new-onset heart failure (HF) in persons with type 2 diabetes (T2D).

METHODS AND RESULTS

We performed a case-control study nested in the Diabetes Care System Cohort, a prospective cohort of persons with T2D in primary care. We included 724 participants, of whom 141 developed HF during 5 years of follow-up and 583 were age- and sex-matched controls. IL-6 was measured at baseline and categorized into four groups: Group 1 was composed of participants with IL-6 below the detection limit of 1.5 pg/mL, and the remainder were divided into tertiles. We performed logistic regression analyses with categorized IL-6 or continuous IL-6 as the determinant and new-onset HF as the outcome adjusted for follow-up time, age, sex, glycated haemoglobin, estimated glomerular filtration rate, albumin/creatinine ratio, and cardiovascular disease at baseline. Effect modification by sex was tested. Participants were 70.7 ± 9.0 years, and 38% were women. In comparison with Group 1, all tertiles were associated with an increased risk of HF with odds ratios of 2.1 [95% confidence interval (CI): 1.2-2.9], 2.8 (95% CI: 2.0-3.7), and 2.1 (95% CI: 1.3-3.0), respectively, for Tertiles 1-3. Continuous IL-6 was associated with the development of HF with an odds ratio of 1.2 (95% CI: 1.0-1.5). No effect modification by sex was observed.

CONCLUSIONS

Higher IL-6 levels are associated with the development of HF in persons with T2D. Further research should determine whether IL-6-lowering interventions could prevent the development of HF.

Sodium-glucose cotransporter 2 inhibitors, inflammation, and heart failure: a two-sample Mendelian randomization study

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT-2) inhibitors are increasingly recognized for their role in reducing the risk and improving the prognosis of heart failure (HF). However, the precise mechanisms involved remain to be fully delineated. Evidence points to their potential anti-inflammatory pathway in mitigating the risk of HF.

METHODS

A two-sample, two-step Mendelian Randomization (MR) approach was employed to assess the correlation between SGLT-2 inhibition and HF, along with the mediating effects of inflammatory biomarkers in this relationship. MR is an analytical methodology that leverages single nucleotide polymorphisms as instrumental variables to infer potential causal inferences between exposures and outcomes within observational data frameworks. Genetic variants correlated with the expression of the SLC5A2 gene and glycated hemoglobin levels (HbA1c) were selected using datasets from the Genotype-Tissue Expression project and the eQTLGen consortium. The Genome-wide association study (GWAS) data for 92 inflammatory biomarkers were obtained from two datasets, which included 14,824 and 575,531 individuals of European ancestry, respectively. GWAS data for HF was derived from a meta-analysis that combined 26 cohorts, including 47,309 HF cases and 930,014 controls. Odds ratios (ORs) and 95% confidence interval (CI) for HF were calculated per 1 unit change of HbA1c.

RESULTS

Genetically predicted SGLT-2 inhibition was associated with a reduced risk of HF (OR 0.42 [95% CI 0.30-0.59], P < 0.0001). Of the 92 inflammatory biomarkers studied, two inflammatory biomarkers (C-X-C motif chemokine ligand 10 [CXCL10] and leukemia inhibitory factor) were associated with both SGLT-2 inhibition and HF. Multivariable MR analysis revealed that CXCL10 was the primary inflammatory cytokine related to HF (MIP = 0.861, MACE = 0.224, FDR-adjusted P = 0.0844). The effect of SGLT-2 inhibition on HF was mediated by CXCL10 by 17.85% of the total effect (95% CI [3.03%-32.68%], P = 0.0183).

CONCLUSIONS

This study provides genetic evidence supporting the anti-inflammatory effects of SGLT-2 inhibitors and their beneficial impact in reducing the risk of HF. CXCL10 emerged as a potential mediator, offering a novel intervention pathway for HF treatment.

The relationship between a series of inflammatory markers on the risk of heart failure in different gender groups: Analysis from NHANES 2015-2018

BACKGROUND

A better understanding of the level-grade inflammation for the development and worsening of heart failure (HF) in different gender groups is an unmet need. We performed an updated analysis on the impact of a series of systemic inflammation markers on HF.

METHODS

This compensatory cross-sectional study enrolled participants from the National Health and Nutrition Examination Survey (NHANES) 2015-2018. HF was based on the self-reported questions. Univariate and multivariate logistic regression were used to investigate the association between systemic immune-inflammation index (SII), high sensitivity C-reactive protein (hs-CRP), lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and HF. For patients of different genders, P for trend was used to analyze potential linear trend relationships and the restricted cubic splines (RCS) were used to describe non-linear relationships. The additive interaction was evaluated by the relative excess risk due to interaction (RERI), attributable proportion (AP), and the synergy index (SI). The multiplicative interaction was evaluated by odds ratio (OR) and 95% confidence interval (CI) of product-term.

RESULTS

A total of 5,830 participants from the NHANES database were divided into two groups: the HF group (n = 210) and the non-HF group (n = 5620). After gender stratification, hs-CRP (OR: 1.01, 95% CI: 1.00-1.03), SII (OR: 1.00, 95% CI: 1.00-1.01), NLR (OR: 1.22, 95% CI: 1.11-1.35) and LMR (OR: 0.79, 95% CI: 0.65-0.93) were independent meaningful factors for HF in males, there was no non-linear relationship between the three factors (SII, NLR, hs-CRP, all P for non-linear > 0.05) and the prevalence of HF, but we detected a non-linear relationship between LMR and the prevalence of HF in males (P for non-linear < 0.05). An additive interaction of hs-CRP and NLR on the risk of HF in males (RERI (OR): 0.67, 95% CI: 0.12-1.34; AP (OR): 0.14, 95% CI: 0.02-0.24; SI (OR): 1.22, 95% CI: 1.03-1.44).

CONCLUSIONS

In summary, hs-CRP, NLR, and LMR are superior meaningful markers for HF in males. SII may be a meaningful systemic inflammation warning marker for HF, which needs to be discriminated against with caution. Only detected a non-linear relationship between LMR and the prevalence of HF in males. NLR and hs-CRP may have an additive interaction in the prevalence of male HF patients. The outcome compensated for previous studies that still needed more studies for validation.

Toxoplasma gondii infection and brain inflammation: A two-sample mendelian randomization analysis

Background

Toxoplasma gondii is an opportunistic parasitic protozoan that can cause highly fatal toxoplasmic encephalitis when the host immune system is compromised. However, the transition from chronic to acute infection remains poorly understood. In this study, we conducted a 180-day observation of tissue damage and inflammation in the brains of mice infected with T. gondii. Subsequently, we investigated the inflammatory factors that T. gondii infection may alter using two-sample Mendelian randomization (MR) analysis.

Methods

We first established a mouse model of T. gondii infection. Subsequently, the mice were euthanized, the brain tissue collected, and immunohistochemistry and hematoxylin and eosin staining performed to observe tissue damage and inflammatory conditions at various time points. Our study also included a published large-scale genome-wide association study meta-analysis that encompassed the circulating concentrations of 41 cytokines. This dataset included 8293 individuals from three independent population cohorts in Finland. Genetic association data for T. gondii were sourced from the Integrative Epidemiology Unit and European Bioinformatics Institute datasets, which included 5010 and 559 individuals of European ancestry, respectively. To assess the causal relationship between T. gondii infection and inflammatory biomarkers, we applied a two-sample MR.

Results

Inflammation and damage resulting from T. gondii infection varied among the distinct regions of the mouse brain. Based on the MR analysis results, three inflammatory biomarkers were chemically assigned to Chemokines and Others, including IP10 (interferon gamma inducible protein-10), MCP1 (monocyte chemoattractant protein-1), and TRAIL (TNF-related apoptosis-inducing ligand).

Conclusion

Our study commenced with the assessment of tissue damage and progression of inflammation in distinct regions of the mouse brain after T. gondii infection. Subsequently, using MR analysis, we detected potential alterations in inflammatory factors associated with this infection. These findings offer valuable insights into the mechanisms underlying toxoplasmic encephalitis and suggest directions for the prevention and treatment of T. gondii infections.

C-Reactive Protein and Risk of Incident Heart Failure in Patients With Cardiovascular Disease

BACKGROUND

Patients with established cardiovascular disease (CVD) are at high risk of incident heart failure (HF), which may in part reflect the impact of systemic inflammation.

OBJECTIVES

The goal of this study was to determine the association between C-reactive protein (CRP) and incident HF in patients with established CVD.

METHODS

Patients from the prospective UCC-SMART (Utrecht Cardiovascular Cohort-Second Manifestations of ARTerial disease) cohort with established CVD, but without prevalent HF were included (n = 8,089). Incident HF was defined as a first hospitalization for HF. The association between baseline CRP and incident HF was assessed using Cox proportional hazards models adjusted for established risk factors (ie, age, sex, myocardial infarction, smoking, diabetes mellitus, body mass index, blood pressure, cholesterol, and kidney function).

RESULTS

During a median follow-up of 9.7 years (IQR 5.4-14.1 years), 810 incident HF cases were observed (incidence rate 1.01/100 person-years). Higher CRP was independently associated with an increased risk of incident HF: HR per 1 mg/L: 1.10 (95% CI: 1.07-1.13), and for last vs first CRP quartile: 2.22 (95% CI: 1.76-2.79). The association was significant for both HF with reduced (HR: 1.09; 95% CI: 1.04-1.14) and preserved ejection fraction (HR: 1.12; 95% CI: 1.07-1.18) (P for difference = 0.137). Additional adjustment for medication use and interim myocardial infarction did not attenuate the association, and the association remained consistent beyond 15 years after the CRP measurement.

CONCLUSIONS

In patients with established CVD, CRP is an independent risk marker of incident HF. These data support ongoing trial efforts to assess whether anti-inflammatory agents can reduce the burden of HF.

C-Reactive Protein Levels and Risk of Cardiovascular Diseases: A Two-Sample Bidirectional Mendelian Randomization Study

Elevated C-reactive protein (CRP) levels are an indicator of inflammation, a major risk factor for cardiovascular disease (CVD). However, this potential association in observational studies remains inconclusive. We performed a two-sample bidirectional Mendelian randomization (MR) study using publicly available GWAS summary statistics to evaluate the relationship between CRP and CVD. Instrumental variables (IVs) were carefully selected, and multiple approaches were used to make robust conclusions. Horizontal pleiotropy and heterogeneity were evaluated using the MR-Egger intercept and Cochran's Q-test. The strength of the IVs was determined using F-statistics. The causal effect of CRP on the risk of hypertensive heart disease (HHD) was statistically significant, but we did not observe a significant causal relationship between CRP and the risk of myocardial infarction, coronary artery disease, heart failure, or atherosclerosis. Our primary analyses, after performing outlier correction using MR-PRESSO and the Multivariable MR method, revealed that IVs that increased CRP levels also increased the HHD risk. However, after excluding outlier IVs identified using PhenoScanner, the initial MR results were altered, but the sensitivity analyses remained congruent with the results from the primary analyses. We found no evidence of reverse causation between CVD and CRP. Our findings warrant updated MR studies to confirm the role of CRP as a clinical biomarker for HHD.

Genetically determined serum bilirubin level and the risk of heart failure: A mendelian randomization study

Background: The association between serum bilirubin level and heart failure (HF) was controversial in previous observational studies and the causal effects of bilirubin on HF have not been investigated. Here, we conducted a Mendelian randomization (MR) study to investigate the associations between genetically determined bilirubin level and HF. Methods: Summary data on the association of single nucleotide polymorphisms (SNPs) with serum bilirubin levels were obtained from genome-wide association study (GWAS) for individuals of European descent and East Asian descent separately. Statistical data for gene-HF associations were extracted from three databases: the HERMES Consortium (47,309 cases and 930,014 controls), FinnGen study (30,098 cases and 229,612 controls) for European population and Biobank Japan (2,820 HF cases and 192,383 controls) for East Asian population. We applied a two-sample Mendelian randomization framework to investigate the causal association between serum bilirubin and HF. Results: Findings from our MR analyses showed that genetically determined serum bilirubin levels were not causally associated with HF risk in either European or East Asian population (odds ratio [OR] = 1.01 and 95% confidence interval [CI] = .97-1.05 for HERMES Consortium; OR = 1.01 and 95% CI = .98-1.04 for FinnGen Study; OR = .82, 95% CI: .61-1.10 for Biobank Japan). These results remained unchanged using different Mendelian randomization methods and in sensitivity analyses. Conclusion: Our study did not find any evidence to support a causal association between serum bilirubin and HF.

Triglyceride-glucose index and the risk of heart failure: Evidence from two large cohorts and a mendelian randomization analysis

BACKGROUND

The relationship between triglyceride-glucose (TyG) index, an emerging marker of insulin resistance, and the risk of incident heart failure (HF) was unclear. This study thus aimed to investigate this relationship.

METHODS

Subjects without prevalent cardiovascular diseases from the prospective Kailuan cohort (recruited during 2006-2007) and a retrospective cohort of family medicine patients from Hong Kong (recruited during 2000-2003) were followed up until December 31st, 2019 for the outcome of incident HF. Separate adjusted hazard ratios (aHRs) summarizing the relationship between TyG index and HF risk in the two cohorts were combined using a random-effect meta-analysis. Additionally, a two-sample Mendelian randomization (MR) of published genome-wide association study data was performed to assess the causality of observed associations.

RESULTS

In total, 95,996 and 19,345 subjects from the Kailuan and Hong Kong cohorts were analyzed, respectively, with 2,726 cases of incident HF in the former and 1,709 in the latter. Subjects in the highest quartile of TyG index had the highest risk of incident HF in both cohorts (Kailuan: aHR 1.23 (95% confidence interval: 1.09-1.39), PTrend <0.001; Hong Kong: aHR 1.21 (1.04-1.40), PTrend =0.007; both compared with the lowest quartile). Meta-analysis showed similar results (highest versus lowest quartile: HR 1.22 (1.11-1.34), P < 0.001). Findings from MR analysis, which included 47,309 cases and 930,014 controls, supported a causal relationship between higher TyG index and increased risk of HF (odds ratio 1.27 (1.15-1.40), P < 0.001).

CONCLUSION

A higher TyG index is an independent and causal risk factor for incident HF in the general population.

CLINICAL TRIAL REGISTRATION

URL: https://www.chictr.org.cn ; Unique identifier: ChiCTR-TNRC-11,001,489.

Inflammation and heart failure: a two-sample Mendelian randomization study

BACKGROUND

It is hypothesized that inflammation leads to heart failure. Results from observational studies thus far have been inconsistent and it is unclear whether inflammation is causally associated with new-onset heart failure. Mendelian randomization analyses are less prone to biases common in observational studies such as reverse causation and unmeasured confounding. The aim of this study was to investigate the causal relation between various inflammatory biomarkers with risk of new-onset heart failure by using a two-sample Mendelian randomization approach.

METHODS

Ten inflammatory biomarkers with available genome-wide association studies (GWAS) among individuals of European ancestry were identified and included C-reactive protein (CRP), immunoglobulin E, tumour necrosis factor (TNF), toll-like receptor 4, interleukin 1 receptor antagonist, interleukin 2 receptor subunit α, interleukin 6 receptor subunit α, interleukin 16, 17 and 18. For the associations between the identified SNPs and heart failure, we used the largest GWAS meta-analysis performed by the Heart Failure Molecular Epidemiology for Therapeutic Targets Consortium with 47 309 participants with heart failure and 930 014 controls. For our main analyses, we used the inverse-variance weighted method.

RESULTS

We included 63 SNPs. CRP, TNF, interleukin 2, 16 and 18 were not associated with heart failure with odds ratios (ORs) of 1.01 [95% confidence interval (95% CI: 0.94-1.09), 1.11 (95% CI: 0.80-1.48), 0.97 (95% CI: 0.93-1.02), 0.99 (95% CI: 0.96-1.03) and 1.01 (95% CI: 0.97-1.06), respectively. The other biomarkers were also not associated with the risk of heart failure and suffered from weak instrument bias.

CONCLUSION

This Mendelian randomization study could not determine a causal relationship between inflammation and risk of heart failure. However, some biomarkers suffered from weak instrument bias.