Analysis of the trajectory of sleep quality changes and influencing factors in maintenance haemodialysis patients in Xinjiang, China: a prospective longitudinal study.
Latent class growth modelling identified four distinct heterogeneous sleep quality trajectories in maintenance haemodialysis patients, with depression as an overarching risk factor for unfavourable trajectories and pruritus and inflammation as specific predictors of persistent poor sleep.
Key Findings
Results
Four distinct sleep quality trajectories were identified among maintenance haemodialysis patients over 6 months.
Trajectories were identified using latent class growth modelling across three timepoints: baseline (T1), 3 months (T2), and 6 months (T3).
The four trajectories were: 'High-Slightly Increasing' (C1, 24.5%), 'Low-Slightly Increasing' (C2, 29.4%), 'High-Declining' (C3, 27.7%), and 'Moderate-Increasing' (C4, 18.4%).
Sleep quality was measured using the Pittsburgh Sleep Quality Index.
The study included 282 MHD patients recruited from nephrology departments of two tertiary hospitals in Urumqi, Xinjiang, China between December 2024 and August 2025.
Results
Baseline depression significantly increased the odds of belonging to unfavourable sleep trajectory groups compared to the 'Low-Slightly Increasing' group (C2).
Depression was assessed using the Self-Rating Depression Scale.
Compared with C2, baseline depression significantly increased the odds of belonging to C1 (OR=8.53, p<0.001).
Baseline depression also significantly increased the odds of belonging to C3 (OR=4.65, p<0.001) and C4 (OR=2.71, p=0.012) compared with C2.
Depression was identified as 'an overarching risk factor for unfavourable trajectories' across multivariable logistic regression analysis.
Results
Pruritus was a specific predictor of persistent poor sleep in the 'High-Slightly Increasing' trajectory (C1) compared to the 'Low-Slightly Increasing' trajectory (C2).
Pruritus was identified as a significant predictor in multivariable logistic regression analysis.
OR for pruritus predicting C1 vs C2 was 2.46 (p=0.019).
Pruritus was described as specifically predicting 'persistent poor sleep' rather than being a general predictor across all unfavourable trajectories.
Results
Elevated C-reactive protein (CRP) was a specific predictor of persistent poor sleep in the 'High-Slightly Increasing' trajectory (C1) compared to the 'Low-Slightly Increasing' trajectory (C2).
CRP was identified as a significant predictor in multivariable logistic regression analysis.
OR for elevated CRP predicting C1 vs C2 was 1.03 (p=0.015).
CRP was described as a marker of inflammation specifically predicting persistent poor sleep alongside pruritus.
Results
Sleep quality trajectories in MHD patients were heterogeneous, underscoring a dynamic rather than static view of sleep quality over time.
The study employed a prospective longitudinal design with three assessment timepoints over 6 months.
Convenience sampling was used and 282 patients completed follow-up assessments.
The use of latent class growth models allowed identification of subgroups with distinct sleep quality change patterns rather than treating the population as homogeneous.
The authors note this finding underscores 'a dynamic view of sleep quality' in MHD care.
What This Means
This research followed 282 kidney dialysis patients in China over six months to understand how their sleep quality changed over time. Rather than assuming all patients experience sleep problems the same way, the researchers used a statistical method to identify distinct groups of patients with different patterns of sleep change. They found four separate groups: one with consistently poor and slightly worsening sleep, one with consistently better sleep, one that started with poor sleep but improved, and one with moderate sleep that got worse. This suggests that dialysis patients are not a uniform group when it comes to sleep, and that their sleep quality can shift meaningfully over just a few months.
The study also identified key factors that predicted which patients ended up in the worse sleep groups. Depression was the strongest and most consistent risk factor — patients with depression at the start of the study were much more likely to have poor sleep trajectories, with the odds being over eight times higher for the persistently poor sleep group compared to the better sleep group. Additionally, skin itching (pruritus) and markers of inflammation in the blood (measured by C-reactive protein) were specifically linked to the group with persistently poor and worsening sleep.
This research suggests that sleep problems in dialysis patients are not fixed and that different patients may need different types of support. Screening dialysis patients for depression, itching, and inflammation early in their care may help identify those at greatest risk for long-term poor sleep. The findings point to the potential value of targeted interventions addressing these specific factors rather than using a one-size-fits-all approach to sleep management in kidney dialysis care.
Tan H, Li L, Zhang Y, Gao J, Lin K. (2026). Analysis of the trajectory of sleep quality changes and influencing factors in maintenance haemodialysis patients in Xinjiang, China: a prospective longitudinal study.. BMJ open. https://doi.org/10.1136/bmjopen-2025-111371