Circulating inflammatory biomarkers and risk of intracranial aneurysm: a Mendelian randomization study

Abstract

Background Intracranial aneurysm (IA) accounts for a substantial source of non-traumatic subarachnoid hemorrhage, with inflammation postulated as a potential factor in its pathogenesis. The present study aims at evaluating the association between circulating inflammatory cytokines and risk of IA under a bidirectional two-sample Mendelian randomization (MR) design. Methods For primary analysis, summary statistics of inflammatory regulators was obtained from a genome-wide association study (GWAS) comprising 8293 Finnish participants. Summary data of IA were extracted from a GWAS which comprised 7495 cases and 71,934 controls in European descent. For targeted analysis, summary statistics were extracted from two proteomic studies, which recruit 3301 and 5368 European participants, respectively. Summary data of IA were acquired from FinnGen study with 5342 cases and 342,673 controls. We employed inverse variance weighted (IVW) method as main approach, with sensitivity analyses using weighted median, MR-Egger, and MR-PRESSO methods. Reverse MR analyses were conducted to minimize bias from reverse causality. Results No causation of cytokines with IA subtypes was identified in both primary and targeted analysis after Bonferroni correction. In primary analysis, vascular endothelial growth factor (VEGF) and fibroblast growth factor basic (bFGF) levels were suggestively associated with aneurysmal subarachnoid hemorrhage (aSAH) [VEGF → aSAH: OR = 1.15, 95%CI 1.04–1.26, P = 0.005; bFGF → aSAH: OR = 0.62, 95% CI 0.42–0.92, P = 0.02]. Statistical significance failed to replicate in targeted analysis. Instead, suggestive protective effects for aSAH were identified in FGF-9 (FGF-9 → aSAH: OR = 0.74, 95% CI 0.62–0.89, P = 0.001) and FGF-16 (FGF-16 → aSAH: OR = 0.84, 95% CI 0.72–0.97, P = 0.017). Furthermore, reverse analyses identified suggestive effect of unruptured IA on RANTES, MIF, GRO-alpha, FGF-16, and FGF-19. Result remained robust after applying sensitivity tests. Conclusions No causality of inflammatory biomarkers on the risk of IA subtypes was identified. Future large-scale studies are in need to evaluate the temporal dynamics of cytokines in conjunction with IA.

Exploring causal correlations of inflammatory biomarkers in idiopathic normal-pressure hydrocephalus: insights from bidirectional Mendelian randomization analysis

“…After Bonferroni correction for multiple comparisons, statistical significance was defined as p < 3.8 × 10 −4 (0.05/132), respectively. p-values ranging from 3.8 × 10 −4 to 0.05 were considered suggestive associations (Fang et al, 2024). For exposures with nominal significance (p < 0.05) in the MR analysis, systematic screening for potential phenotypes correlated with confounders was conducted through LDlink.…”

Causal associations of Helicobacter pylori antibodies with unruptured Intracranial Aneurysm and Subarachnoid Hemorrhage: A Two-Sample Mendelian Randomization Study

“…The H.pylori protein Antibody GWAS dataset, from the UK Biobank, contained up to 8,735 individuals with anti-Helicobacter pylori antibody levels. Helicobacter pylori IgG, GroEL, OMP, urea, CagA, VacA and catalase [6].We used single nucleotide polymorphisms (SNPS) associated with Helicobacter pylori antibodies as instrumental variables (IVs) to evaluate our data from 2127 cases involving Aneurysms, operations, SAH, Fourteen SNPS associated with UIA and Aneurysms, operations, and SAH were extracted from large GWAS of 992 UIA cases and 203,068 controls [20].The MR Analysis was performed on two aggregated data sets from the GWAS.The two combined datasets were the UIA (n = 992) and the Aneurysms, operations, SAH (n = 2127) of individuals of European descent and the GWAS of the control group (n = 203068) [20].All summary data used in this study by the department of comprehensive medical research council epidemiology (MRC -IEU) OpenGWAS uni ed archive (https://gwas.mrcieu.ac.uk/).…”

Table_1.XLSX

“…After Bonferroni correction for multiple comparisons, statistical significance was defined as p < 3.8 × 10 −4 (0.05/132), respectively. p-values ranging from 3.8 × 10 −4 to 0.05 were considered suggestive associations (Fang et al, 2024). For exposures with nominal significance (p < 0.05) in the MR analysis, systematic screening for potential phenotypes correlated with confounders was conducted through LDlink.…”