Remnant cholesterol and auditory outcomes in NHANES 1999–2018: associations with frequency-specific hearing loss and tinnitus

Background Evidence on the lipid determinants of auditory outcomes remains inconsistent. Remnant cholesterol (RC)—the cholesterol content of triglyceride-rich lipoproteins—captures atherogenic and inflammatory burdens beyond conventional fractions. This study assessed the associations of RC hearing loss (HL) across frequency bands and with tinnitus based on data from a population-representative U.S. cohort. Methods Participants aged 40 years and older with valid audiometric evaluations and fasting lipid profiles were identified from the 1999–2018 NHANES dataset. Remnant cholesterol was estimated as total cholesterol minus the sum of LDL-C and HDL-C, and evaluated across predetermined concentration ranges. The outcomes included low-, speech-, and high-frequency hearing loss defined by air-conduction thresholds and self-reported tinnitus. Weighted multivariable logistic regression models were applied, sequentially adjusting for demographic, socioeconomic, lifestyle, and clinical covariates, followed by mutual adjustment for other lipid components. Subgroup and interaction analyses evaluated effect modification, including noise exposure. Results In fully adjusted survey-weighted logistic models, higher RC was associated with HL (OR 2.43 , 95% CI 1.71–3.47 ) and with tinnitus (OR 1.64 , 95% CI 1.31–2.06 ); category analyses indicated a monotonic increase ( P for trend < 0.001). Associations displayed a clear dose–response across RC categories and remained robust in mutually adjusted models, whereas the inverse associations for HDL-C attenuated and became non-significant once RC was included. Frequency-specific analyses revealed the strongest associations for high-frequency hearing loss, intermediate associations for speech frequencies, and the weakest associations for low-frequency hearing loss. Subgroup findings were broadly consistent across strata, and interaction testing indicated amplified RC–auditory associations among participants reporting noise exposure. Conclusions Remnant cholesterol was linked to adverse auditory outcomes—hearing loss and tinnitus—with clear dose–response patterns that persisted after mutual lipid adjustment. RC may reflect a metabolically driven susceptibility relevant for risk stratification; confirmation in longitudinal cohorts and trials is required.