BackgroundFew studies have evaluated the association between polyunsaturated fatty acids (PUFAs) and hearing levels. This study aimed to investigate the association between serum PUFAs and hearing threshold shifts in US adults.MethodsWe investigated 913 adults from the National Health and Nutrition Examination Survey (NHANES) 2011–2012. Multivariate linear regression analyses were conducted to evaluate associations between PUFA and hearing threshold shifts.ResultsOverall, 11 serum PUFAs were inversely associated with low-frequency thresholds, especially in men, and were positively related to high-frequency thresholds, particularly in the 40–59 years old cohort. Furthermore, some serum PUFAs were positively associated with both hearing threshold subgroups in women.ConclusionSome PUFAs tend to be beneficial for low-frequency hearing status and detrimental to the high-frequency hearing threshold. The male sex may play a protective role in this association, while the female sex and middle age may be detrimental in the effect of PUFAs on hearing function.

BackgroundAlthough telomere length has a significant relationship with various age-related diseases, studies on its relationship with hearing status in adults are limited and equivocal. This study investigated the associations between mean telomere length (MTL) and low-, speech-, and high-frequency hearing threshold shifts of adults in the United States.MethodsA total of 2,027 adults, aged 20-69 years, from the National Health and Nutrition Examination Surveys (NHANES, 1999–2002) were included in the analytic sample. The quantitative polymerase chain reaction method was used for the MTL assay, and MTL was expressed using the telomere-to-single copy gene (T/S) ratio. Hearing loss was defined as a pure-tone average (PTA) for the better ear at ≥ 20 dB HL at frequencies 500, 1,000, 2,000, and 4,000 Hz. Univariate and multivariate linear regression analyses and smooth curve fittings were conducted to evaluate the correlation between MTL and low-, speech-, and high-frequency hearing levels.ResultsThe mean age of the participants was 40.60 ± 12.76 years, including 952 men (weighted, 48.67%) and 303 (weighted, 12.88%) participants with hearing loss. After adjusting for potential confounders in the multivariate linear regression model, the relationship between MTL and hearing thresholds was not statistically significant. Smooth curve fittings indicated a non-linear relationship between MTL and high-frequency PTA hearing threshold shifts. MTL was inversely related to high-frequency PTA to the turning point (T/S ratio = 0.82) (adjusted β−21.45, 95% CI −37.28, −5.62; P = 0.008). When the T/S ratio exceeded0.82, MTL was not associated with high-frequency PTA (adjusted β0.18, 95% CI −2.21, 2.57; P = 0.8809).ConclusionOur findings revealed that MTL was associated with high-frequency PTA hearing threshold shifts of adults in the United States in a non-linear manner.