Sleep Disturbance at Cancer Diagnosis and Its Associations With Depressive Symptoms and Systemic Inflammatory Burden

Sleep disturbance is highly prevalent among cancer patients and closely associated with depressive symptoms. However, it remains unclear whether sleep problems present at cancer diagnosis primarily reflect depression or also indicate an underlying biological susceptibility.

This study aimed to examine the relationships between sleep disturbance, depressive symptoms, and systemic inflammatory-nutritional burden in newly diagnosed, treatment-naïve cancer patients.

In this cross-sectional study, sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) in patients at diagnosis before oncological treatment. Poor sleep quality (PSQ) was defined as PSQI ≥ 5, and sleep disturbance severity was evaluated using the total PSQI score. Depressive symptoms were measured with the Hospital Anxiety and Depression Scale-Depression subscale (HADS-D). Systemic inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR) and lactate dehydrogenase-to-albumin ratio (LAR), were calculated from routine laboratory data. Multivariable logistic regression and generalized linear models assessed factors associated with PSQ and sleep disturbance severity, respectively. Receiver operating characteristics (ROC) analyses evaluated the discriminatory performance of depressive symptoms and inflammatory indices. Stratified analyses were conducted according to depression status (HADS-D < 8 vs. ≥ 8).

Sleep disturbance was highly prevalent at diagnosis. Depressive symptom burden was independently associated with both PSQ and higher PSQI scores. Importantly, systemic inflammatory indices remained independently associated with sleep disturbance after adjustment for depressive symptoms and clinical variables. NLR showed moderate discriminatory ability for PSQ, while LAR was independently associated with sleep disturbance severity. ROC analyses indicated that depressive symptoms and inflammatory burden jointly improved discrimination of PSQ. In stratified analyses, LAR remained significantly associated with PSQI scores regardless of depression status.

Sleep disturbance at cancer diagnosis is independently associated with both depressive symptoms and systemic inflammatory-nutritional burden, suggesting that it may reflect not only psychological distress but also underlying biological processes. Routine sleep assessment alongside inflammatory markers may help identify vulnerable patients and support early supportive care planning.