Impact of hyperlipidemia as a coexisting factor on the prognosis of idiopathic sudden sensorineural hearing loss: A propensity score matching analysis

Objective To define the impact of hyperlipidemia as a coexisting factor on the prognosis of Idiopathic Sudden Sensorineural Hearing Loss (ISSHL), we prospectively analysed the Lipid-lowering therapy Group (LLTG) data compared with Control Group (CG) data to determine the effects of Lipid intervention on the prognosis of sudden hearing loss. Design A prospective, non-randomized study. Setting Shandong Provincial Hospital Affiliated to Shandong University, Shandong, China. Participants A total of 653 in-patient SSHL patients were enrolled between January 2014 to August 2018. Main outcome measures From January 2014 to August 2018, 653 patients with ISSHL who also had hyperlipidemia as coexisting factor were identified. Patients enrolled in LLTG (n = 200) or CG (n = 453) were compared by a propensity score matching analysis (PSM, caliper = 0.01, n = 2) to balance pre-existing clinical characteristics. After matching, the effective rate of different hyperlipidemia types and different types of audiogram in both groups were performed by Cochran-Mantel-Haenszel test (CMH). Results After PSM, 440 patients were studied (146 in LLTG, 294 in CG), and the influence of interference factors was balanced, meanwhile, the final hearing level was better in LLTG than CG (P = .043), and hearing gain was higher in LLTG than CG (P = .006). Cure rate (32.9%), significant improvement rate (22.6%) and the total effective rate (76.0%) in LLTG were better than that in CG group (26.5%, 15.6% and 63.6%) after the Pearson chi-square test (P < .05). Analysis with the Cochran-Mantel-Haenszel test showed that the total effective rate was better in LLTG than CG respectively (P = .009) in each different hyperlipidemia types, and there were statistically significant differences in TG higher group (TG Group; P = .018). Moreover, the total effective rate was better in LLTG than CG (P = .006) for all patterns of audiogram, and there were statistically significant differences in flat audiogram (P = .043). Conclusions Lipid-lowering therapy can improve the curative effect of sudden hearing loss patients combined with hyperlipidemia. There was a significant difference in the total effective rate of TG Group after lipid intervention, suggesting that there might be causal relationship between TG and sudden hearing loss. There was a significant difference in the total effective rate between flat audiogram, which may suggest flat hearing loss was more likely caused by vascular dysfunction.