Systematic review on metabolic and cardiovascular factors and their relationship to hearing loss

ABSTRACT Introduction: Hearing loss is a multifactorial condition affecting millions of people worldwide, studies suggest a link between dyslipidemia and hearing function. Hypotheses have proposed the influence of elevated triglyceride levels which may contribute to vascular changes in the inner ear, affecting hearing. Methodology: A systematic review was conducted under the PRISMA guidelines, searching databases such as PubMed, Scopus, ScienceDirect and SpringerLink. We included studies published within a window of no more than seven years that analysed the relationship between triglycerides and hearing loss. Results: Seventeen studies were selected that indicated a significant association between dyslipidemia and hearing loss, especially in cases of sudden hearing loss. In these studies, elevated triglyceride levels and a high triglyceride-glucose ratio (TG) were found to increase the risk of hearing loss, while elevated HDL levels appear to have a protective effect. The influence of metabolic syndrome and hypertension were also identified as being associated with an increased risk of hearing impairment. Discussion: The findings suggest that dyslipidemia and metabolic factor negatively influence the inner ear microcirculation process. However, despite the methodological limitations of each study, they suggest monitoring lipid levels in the auditory relationship. Conclusions: Control of metabolic factors such as triglycerides and hypertension could play a key role in the prevention of hearing impairment.