Table_2_Exploring the Association of Leukocyte Telomere Length and Hearing Threshold Shifts of Adults in the United States.docx

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.

背景 尽管端粒长度与多种年龄相关性疾病存在显著关联，但目前针对成人端粒长度与听力状态之间关系的研究仍较为有限且结论不一。本研究旨在探究美国成年人平均端粒长度（mean telomere length, MTL）与低频、言语频率及高频听阈偏移的相关性。

方法 本研究的分析样本纳入了来自1999-2002年美国国家健康与营养检查调查（National Health and Nutrition Examination Surveys, NHANES）的2027名年龄在20-69岁之间的成年人。采用定量聚合酶链式反应法检测平均端粒长度，以端粒与单拷贝基因比值（T/S比值）表示平均端粒长度。听力损失定义为：双耳中较好耳在500Hz、1000Hz、2000Hz及4000Hz频率下的纯音听阈均值（pure-tone average, PTA）≥20分贝听力级（dB hearing level, dB HL）。通过单因素及多因素线性回归分析、平滑曲线拟合，评估平均端粒长度与低频、言语频率及高频听力水平的相关性。

结果 研究对象的平均年龄为40.60±12.76岁，其中男性952名（加权后占比48.67%），听力损失受试者303名（加权后占比12.88%）。在多因素线性回归模型中校正潜在混杂因素后，平均端粒长度与听阈之间的关联未达到统计学显著性。平滑曲线拟合结果显示，平均端粒长度与高频纯音听阈均值的听阈偏移呈非线性相关关系：在转折点（T/S比值=0.82）之前，平均端粒长度与高频纯音听阈均值呈负相关（校正后β=-21.45，95%置信区间：-37.28~-5.62；P=0.008）；当T/S比值超过0.82时，平均端粒长度与高频纯音听阈均值无显著关联（校正后β=0.18，95%置信区间：-2.21~2.57；P=0.8809）。

结论 本研究结果显示，美国成年人的平均端粒长度与高频纯音听阈均值的听阈偏移呈非线性相关关系。