Interactive effect of sleep duration and trouble sleeping on frailty in chronic kidney disease: findings from NHANES, 2005–2018

Both sleep disorders and chronic kidney disease (CKD) are recognized as significant public health concerns. In the general population, sleep disorders have been shown to be associated with frailty in the elderly. This study aims to evaluate the association between sleep duration and trouble sleeping with frailty in CKD patients, as well as the potential interactive effect between these two factors.
This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey (NHANES) spanning 2005–2018. Sleep duration and trouble sleeping was self-reported. Frailty was assessed using a 49-item frailty index. The associations between sleep duration, trouble sleeping, and frailty were analyzed using weighted multivariate logistic regression and restricted cubic splines. Subgroup analysis was conducted to determine the consistency of the study’s conclusions across various subgroups.
A total of 5,211 adult CKD patients were included in this analysis. Regression analysis results indicated that short sleep duration (OR = 1.364, 95% CI: 1.152–1.616), long sleep duration (OR = 1.648, 95% CI: 1.259–2.157), and trouble sleeping (OR = 2.572, 95% CI: 2.102–3.147) were significantly associated with an increased risk of frailty in CKD patients, with an interaction between sleep duration and trouble sleeping. Subgroup analysis revealed that the effects of trouble sleeping and sleep duration on frailty symptoms in CKD patients exhibit significant variation across age groups (p < 0.05 for interaction), with no notable differences observed in other subgroups. RCS results demonstrated a U-shaped relationship between frailty and sleep duration, with the lowest risk of frailty at 7.12 h of sleep.
Our findings indicated that both sleep duration and trouble sleeping were significantly associated with frailty in CKD patients, with a notable interaction between these two factors. Therefore, prevention and intervention strategies for frailty in CKD patients should address multiple aspects of sleep health.

睡眠障碍与慢性肾脏病（CKD）均为公认的重要公共卫生问题。在一般人群中，已有研究证实睡眠障碍与老年人群衰弱症状存在显著关联。本研究旨在探讨慢性肾脏病患者的睡眠时长、睡眠困扰与衰弱之间的关联，以及这两个因素间的潜在交互效应。

本项横断面研究分析了2005至2018年美国国家健康与营养调查（NHANES）的相关数据。睡眠时长与睡眠困扰情况均由受试者自我报告所得。衰弱状态通过49项衰弱指数进行评估。采用加权多因素logistic回归与限制性立方样条（restricted cubic splines）模型，分析睡眠时长、睡眠困扰与衰弱三者间的关联。此外开展亚组分析，以验证研究结论在不同亚组中的一致性。

本研究共纳入5211名成年慢性肾脏病患者。回归分析结果显示，短睡眠时长（优势比OR=1.364，95%置信区间CI:1.152~1.616）、长睡眠时长（OR=1.648，95%CI:1.259~2.157）以及睡眠困扰（OR=2.572，95%CI:2.102~3.147）均与慢性肾脏病患者的衰弱风险升高显著相关，且睡眠时长与睡眠困扰之间存在交互效应。亚组分析结果表明，睡眠困扰与睡眠时长对慢性肾脏病患者衰弱症状的影响在不同年龄组间存在显著差异（交互项P<0.05），而在其他亚组中未观察到显著差异。限制性立方样条分析结果显示，衰弱风险与睡眠时长呈U型关联，当睡眠时长为7.12小时时，衰弱风险最低。

本研究结果表明，睡眠时长与睡眠困扰均与慢性肾脏病患者的衰弱状态显著相关，且二者间存在显著交互效应。因此，针对慢性肾脏病患者的衰弱预防与干预策略，应兼顾睡眠健康的多个维度。