A case-control study on proinflammatory genetic polymorphisms on sudden sensorineural hearing loss.

OBJECTIVES/HYPOTHESIS: Sudden sensorineural hearing loss (SSNHL) is strictly related to inner ear vascular injuries and recently to some atherosclerotic risk factors. The pathogenic role of inflammatory molecules in atherosclerosis is well established. However, there is little knowledge about the potential role of inflammatory cytokines and adhesion molecules on SSNHL etiology. STUDY DESIGN: The aim of this study was to evaluate the role of proinflammatory genetic polymorphisms of the MCP-1 (CCL2), E-selectin, and interleukin (IL)-6 gene in SSNHL patients. METHODS: We evaluated the frequency and distribution of selected single nucleotide polymorphisms of the MCP-1 (CCL2), E-selectin, and IL-6 gene in 87 SSNHL patients and 107 healthy controls. RESULTS: Our results did not show significant difference between the compared groups for MCP-1 and E-selectin genes, whereas a significant difference was reported for the IL-6 gene (P < .0001). CONCLUSIONS: The main finding of our study is that the 174G/G polymorphism (with a wider distribution of wt/wt genotype in SSNHL patients than in the healthy controls) of the IL-6 gene is significantly associated with the risk of SSNHL, which is consistent with a previous finding on serum levels of IL-6 in SSNHL. It is possible that the variant acts as a triggering agent of different lipidemia-related phenotypes. Both the -174G/G polymorphism and elevated IL-6 levels in SSNHL patients could suggest that IL-6 plays a role in the inner ear involvement by atherosclerotic inflammatory events.

Combined effect of inflammatory gene polymorphisms and the risk of ischemic stroke in a prospective cohort of subjects with type 2 diabetes: a Go-DARTS study.

OBJECTIVE: We have previously observed that genetic profiles determined by the combination of five functionally significant single nucleotide polymorphisms (SNPs) (rs1800795, rs5498, rs5361, rs1024611, and rs679620) of genes encoding prototypical inflammatory molecules are associated with history of ischemic stroke. Here we tested the ability of this multigenic model to predict stroke risk in a large population-based prospective cohort of subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: This study was conducted using a prospective cohort of individuals with type 2 diabetes participating in the Go-DARTS (Genetics of Diabetes Audit and Research in Tayside Scotland) study, which includes genetic and clinical information of patients with diabetes within the Tayside region of Scotland, U.K. The above-mentioned inflammatory SNPs were investigated in 2,182 Go-DARTS participants. We created an inflammatory risk score (IRS), ranging from 0 to 5, according to the number of "at-risk" genotypes concomitantly carried by a given individual. The primary outcome was the occurrence of fatal or nonfatal stroke of any kind. Mean follow-up time was 6.2 ± 1.1 years. RESULTS: The incidence of stroke increased according to the IRS. The IRS was significantly and independently associated with increased stroke risk after adjustment for other conventional risk factors (hazard ratio 1.34 [95% CI 1.1-1.7]; P = 0.009). The highest hazard ratio for stroke was found in subjects concomitantly carrying > 3 proinflammatory variations and in subjects without previous cardiovascular diseases. CONCLUSIONS: This large prospective cohort study provides evidence that SNPs of genes encoding prototypical inflammatory molecules may be used to create multigenic models that predict stroke risk in subjects with type 2 diabetes.