Frailty transitions and risk of chronic kidney disease: insights from the China Health and Retirement Longitudinal Study

Frailty is increasingly recognized as a critical factor in the risk of chronic kidney disease (CKD), and it is also a condition that can undergo transitions. However, the relationship between frailty transitions and CKD risk in aging populations remains underexplored. This study aims to investigate the association between frailty transitions and CKD risk in middle-aged and older adults using data from the China Health and Retirement Longitudinal Study. Frailty was assessed using a 40-item Frailty Index (FI), with participants categorized into three groups: robust (FI ≤ 0.10), pre-frail (0.10 0.21). Frailty transitions were tracked between the first and second waves of the study. Data on CKD incidence were obtained from self-reported physician-diagnosed kidney disease. Cox proportional hazards models were employed to evaluate the risk of CKD, with adjustments made for potential confounders. Among 12,050 participants (52.60% female, mean age 58.37), those who progressed to frailty or pre-frailty had an increased risk of CKD compared with stable participants (HR 1.74, p p = 0.023). The results of the sensitivity analysis, which showed consistent findings, support the reliability of the results. Frailty transitions are significantly associated with the risk of CKD. Worsening frailty is linked to an increased risk of CKD, while improvement in frailty is associated with a lower risk of CKD.越来越多研究证实，衰弱（frailty）是慢性肾脏病（chronic kidney disease, CKD）发病风险的关键影响因素，且衰弱状态可发生动态转变。然而，衰老人群中衰弱状态转变与CKD发病风险之间的关联仍未得到充分探索。本研究依托中国健康与养老追踪调查（China Health and Retirement Longitudinal Study）数据，旨在探究中老年人群衰弱状态转变与CKD发病风险之间的关联。研究采用包含40个条目的衰弱指数（Frailty Index, FI）评估衰弱状态，将研究对象分为三组：健壮组（FI ≤ 0.10）、衰弱前期组（0.10 < FI < 0.21）以及衰弱组（FI ≥ 0.21）。本研究追踪了第一波与第二波调查间的衰弱状态转变情况。CKD发病数据来源于研究对象自我报告的经医师确诊的肾脏疾病病史。本研究采用Cox比例风险回归模型（Cox proportional hazards models）评估CKD发病风险，并对潜在混杂因素进行了校正。本研究共纳入12050名研究对象（女性占比52.60%，平均年龄58.37岁），与衰弱状态稳定的研究对象相比，进展为衰弱或衰弱前期的人群CKD发病风险显著升高（风险比[HR] 1.74，p < 0.001；风险比[HR] 1.25，p = 0.023）。敏感性分析结果与本研究核心发现一致，证实了研究结果的可靠性。衰弱状态转变与CKD发病风险存在显著关联：衰弱状态恶化会升高CKD发病风险，而衰弱状态改善则会降低CKD发病风险。