The Relationship Between Blood Lipids, Coagulation Indexes, Blood Homocysteine and Sudden Deafness: A Retrospective Study and Mendelian Randomization Analysis

ABSTRACT Background Certain blood components, including blood lipids, coagulation parameters, and homocysteine, have been suggested to correlate with the incidence and prognosis of sudden sensorineural hearing loss (SSNHL). However, the nature of these associations remains controversial. Methods A retrospective study was conducted between January 2020 and December 2024. A total of 308 patients with SSNHL who received short‐term combined therapy and 169 healthy controls were included from our hospital. Initially, baseline clinical indicators were compared between the patient group and the control group. Subsequently, patients were further stratified into four subgroups according to their hearing recovery outcomes for more detailed inter‐group comparisons, and the impact of these indicators on SSNHL incidence and prognosis was assessed. To further investigate potential causality, Mendelian randomization (MR) analysis was performed to examine the relationship between genetically predicted blood components and SSNHL. Results Our retrospective analysis revealed significant differences between the patient and control groups in the following parameters at admission: plasma fibrinogen at admission (PRE‐FIB), activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), total cholesterol (CHOL), high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol (LDL‐C), and triglycerides (TG). Among the four groups stratified by hearing recovery, differences were observed in admission hearing level (dB), the change in plasma fibrinogen after the first batroxobin injection relative to baseline (DIFF‐FIB), and CHOL. MR analysis using the random‐effects inverse‐variance weighted (IVW) method indicated a significant causal relationship between genetically predicted lipid levels and SSNHL. Additionally, genetically predicted S‐adenosylhomocysteine and fibrinogen were identified as potential risk factors for SSNHL. Conclusions PRE‐FIB, APTT, TT, PT, CHOL, HDL‐C, LDL‐C, and TG may be associated with the onset of SSNHL. Admission hearing level (dB), DIFF‐FIB, and CHOL could play a role in predicting hearing recovery after SSNHL. MR analysis provides causal evidence supporting lipids, fibrinogen, and S‐adenosylhomocysteine as potential risk factors for SSNHL.