Supplementary Material for: Telomere length among Chinese aged 75+ years

Introduction: Telomere length (TL) is generally regarded as a biomarker of aging. TL, which is influenced by sociodemographic factors, has been shown to be inversely associated with morbidity. However, most studies examined the youngest old and whether the findings can be extended to older individuals is less clear. Further, few studies have examined these questions in Chinese older adults. This cross-sectional study examined TL and its associated factors in Chinese aged 75+ years in Hong Kong. Methods: Participants were from the Mr. and Ms. Osteoporosis cohort. A structured interview on sociodemographic factors and physical measurement was conducted. Frailty and sarcopenia status were respectively determined by Fried’s criteria and Asian Working Group for Sarcopenia definition. TL was measured by a molecular inversion probe - quantitative PCR (MIP-qPCR) assay and expressed as a novel telomere / a single copy reference gene (T/S) ratio. Adjusted binary logistic regressions were used to examine the associations between TL and the presence of multimorbidity, age-related diseases, frailty and sarcopenia. Results: Among 555 participants (mean age 83.6±3.8 years, 41.3% women), the mean T/S ratio was 1.01±0.20. Males had a lower T/S ratio (0.97±0.20) compared with females (1.07±0.18) (p<0.001). A lower education level was related to a longer TL (p=0.016). Being a current smoker was related to a shorter TL (p=0.007). TL was not significantly different across categories of age, subjective socioeconomic status, drinking status, physical activity level and body mass index (p>0.05). There were no associations between TL and the presence of multimorbidity, diabetes, stroke, cardiovascular diseases, cognitive impairment, frailty and sarcopenia. Conclusion: Among Chinese aged 75+ years, males had shorter TL compared with females. TL was not associated with age-related diseases, frailty and sarcopenia in this age group. TL may not be a biological marker of aging among older individuals.

引言：端粒长度（Telomere Length, TL）通常被视为衰老的生物标志物。端粒长度受社会人口学因素影响，且已被证实与患病风险呈负相关。然而，现有研究大多聚焦于年轻老年群体，上述结论能否推广至更高龄人群尚不明确。此外，针对中国高龄老年群体开展此类研究的报道极少。本横断面研究旨在探讨中国香港地区75岁及以上老年人群的端粒长度及其影响因素。方法：研究对象来自「骨质疏松队列（Mr. and Ms. Osteoporosis cohort）」。研究采用结构化访谈收集社会人口学相关信息，并开展体格测量。衰弱状态与肌少症状态分别依据Fried标准及亚洲肌少症工作组（Asian Working Group for Sarcopenia, AWGS）的定义进行判定。端粒长度通过分子倒置探针-定量聚合酶链反应（MIP-qPCR）法检测，并以新型端粒/单拷贝参考基因比值（T/S比值）表示。采用校正后的二元逻辑回归模型分析端粒长度与共病、年龄相关性疾病、衰弱及肌少症发生风险之间的关联。结果：本研究共纳入555名研究对象，平均年龄为83.6±3.8岁，女性占比41.3%。研究对象的平均T/S比值为1.01±0.20。男性的T/S比值（0.97±0.20）低于女性（1.07±0.18），差异具有统计学意义（p<0.001）。较低的受教育水平与更长的端粒长度相关（p=0.016）；当前吸烟与更短的端粒长度相关（p=0.007）。端粒长度在不同年龄分组、主观社会经济地位、饮酒状态、体力活动水平及体重指数（BMI）分组间无显著差异（p>0.05）。未观察到端粒长度与共病、糖尿病、脑卒中、心血管疾病、认知障碍、衰弱及肌少症的发生存在显著关联。结论：在中国香港地区75岁及以上的老年人群中，男性端粒长度显著短于女性。本研究群体中，端粒长度与年龄相关性疾病、衰弱及肌少症均无显著关联，提示端粒长度或许并非该高龄老年群体的衰老生物标志物。