提出了以脆弱指数作为衡量老年人衰老程度的方法。然而，少有研究调查了是否在年轻时以同样的年龄测量脆弱指数能预测新的与年龄相关的疾病的发展情况。 本次回顾性全国队列研究利用韩国国家医疗保险数据库，检索了在2007年1月1日至2017年12月31日之间在66岁参加国家转型年龄筛查计划的968 885名韩国人。研究数据分析时间为2020年10月1日至2022年1月。使用39项脆弱指数来定义脆弱度，指数范围从0到1.00，分为强健型(<0.15)、前脆弱型(0.15-0.24)、轻度脆弱型(0.25-0.34)和中度至重度脆弱型(≥0.35)。 本次研究的主要研究结果为全因死亡。次要研究结果为8种与年龄相关的慢性疾病（充血性心力衰竭，冠状动脉疾病，中风，2型糖尿病，癌症，痴呆，跌倒和骨折）以及符合长期护理服务条件的残疾。使用Cox比例风险回归、特定原因和子分配风险回归，研究了直到最早的死亡日期、相关年龄相关疾病发生时间、筛查检查后10年或2019年12月31日为止的结果风险比率（HRs）和95% CI。 在分析的968 885名参与者中（517 052名女性[53.4%]），大部分被归类为强壮（65.2%）或前脆弱（28.2%）；只有极小部分被归类为轻度脆弱（5.7%）或中度至重度脆弱（1.0%）。平均脆弱指数为0.13（SD，0.07），有64 415人（6.6%）为脆弱。 在校正社会人口学和生活方式特征后，中度至重度脆弱与死亡率（HR，4.43 [95% CI，4.24-4.64]）和新诊断的所有慢性疾病，包括充血性心力衰竭（校正特定原因HR，2.90 [95% CI，2.67-3.15]），冠状动脉疾病（校正特定原因HR，1.98 [95% CI，1.85-2.12]），中风（校正特定原因HR，2.22 [95% CI，2.10-2.34]），糖尿病（校正特定原因HR，2.34 [95% CI，2.21-2.47]），癌症（校正特定原因HR，1.10 [95% CI，1.03-1.18]），痴呆（校正特定原因HR，3.59 [95% CI，3.42-3.77]），跌倒（校正特定原因HR，2.76 [95% CI，2.29-3.32]），骨折（校正特定原因HR，1.54 [95% CI，1.48-1.62]）和残疾（调整后的根据特定原因HR，10.85 [95% CI，10.00-11.70]）的发病率增加相关。除了癌症（中度至重度脆弱校正子分配HR，0.99 [95% CI，0.92-1.06]）外，脆弱与所有结果的10年发生率增加相关。在66岁时的脆弱性与在接下来的10年内获取年龄相关疾病（强壮组的平均[SD]条件为每年0.14 [0.32]，而中度至重度脆弱组为0.45 [0.87]）显著相关。 本次队列研究的发现表明，在66岁时测量的脆弱指数与在接下来的10年内更快地获得年龄相关疾病、残疾和死亡相关。在这个年龄段测量脆弱性可能提供了预防年龄相关健康退步的机会。

A frailty index has been proposed as a measure of aging among older individuals. However, few studies have examined whether a frailty index measured at the same chronologic age at younger ages could forecast the development of new age-related conditions.To examine the association of the frailty index at 66 years of age with incident age-related diseases, disability, and death over 10 years.This retrospective nationwide cohort study used the Korean National Health Insurance database to identify 968 885 Korean individuals who attended the National Screening Program for Transitional Ages at 66 years of age between January 1, 2007, and December 31, 2017. Data were analyzed from October 1, 2020, to January 2022.Frailty was defined using a 39-item frailty index ranging from 0 to 1.00 as robust (<0.15), prefrail (0.15-0.24), mildly frail (0.25-0.34), and moderately to severely frail (≥0.35).The primary outcome was all-cause death. Secondary outcomes were 8 age-related chronic diseases (congestive heart failure, coronary artery disease, stroke, type 2 diabetes, cancer, dementia, fall, and fracture) and disability qualifying for long-term care services. Cox proportional hazards regression and cause-specific and subdistribution hazards regression were used to examine hazard ratios (HRs) and 95% CIs for the outcomes until the earliest of date of death, the occurrence of relevant age-related conditions, 10 years from the screening examination, or December 31, 2019.Among the 968 885 participants included in the analysis (517 052 women [53.4%]), the majority were classified as robust (65.2%) or prefrail (28.2%); only a small fraction were classified as mildly frail (5.7%) or moderately to severely frail (1.0%). The mean frailty index was 0.13 (SD, 0.07), and 64 415 (6.6%) were frail. Compared with the robust group, those in the moderately to severely frail group were more likely to be women (47.8% vs 61.7%), receiving medical aid insurance for low income (2.1% vs 18.9%), and less active (median, 657 [IQR, 219-1133] vs 319 [IQR, 0-693] metabolic equivalent task [min/wk]). After adjusting for sociodemographic and lifestyle characteristics, moderate to severe frailty was associated with increased rates of death (HR, 4.43 [95% CI, 4.24-4.64]) and new diagnosis of all chronic diseases, including congestive heart failure (adjusted cause-specific HR, 2.90 [95% CI, 2.67-3.15]), coronary artery disease (adjusted cause-specific HR, 1.98 [95% CI, 1.85-2.12]), stroke (adjusted cause-specific HR, 2.22 [95% CI, 2.10-2.34]), diabetes (adjusted cause-specific HR, 2.34 [95% CI, 2.21-2.47]), cancer (adjusted cause-specific HR, 1.10 [95% CI, 1.03-1.18]), dementia (adjusted cause-specific HR, 3.59 [95% CI, 3.42-3.77]), fall (adjusted cause-specific HR, 2.76 [95% CI, 2.29-3.32]), fracture (adjusted cause-specific HR, 1.54 [95% CI, 1.48-1.62]), and disability (adjusted cause-specific HR, 10.85 [95% CI, 10.00-11.70]). Frailty was associated with increased 10-year incidence of all the outcomes, except for cancer (moderate to severe frailty adjusted subdistribution HR, 0.99 [95% CI, 0.92-1.06]). Frailty at 66 years of age was associated with greater acquisition of age-related conditions (mean [SD] conditions per year for the robust group, 0.14 [0.32]; for the moderately to severely frail group, 0.45 [0.87]) in the next 10 years.The findings of this cohort study suggest that a frailty index measured at 66 years of age was associated with accelerated acquisition of age-related conditions, disability, and death over the next 10 years. Measuring frailty at this age may offer opportunities to prevent age-related health decline.