The associations between insomnia symptoms and clinical features, lipid metabolism parameters, as well as inflammatory cytokines in patients with chronic schizophrenia.

BACKGROUND

Chronic schizophrenia is commonly associated with a high incidence of insomnia. Co-morbid insomnia not only exacerbates psychiatric symptoms but also significantly impairs cognitive functioning, and increases the risk of suicide. Therefore, this study sought to explore the relationships between insomnia symptoms and clinical features, lipid metabolism parameters, and inflammatory cytokines in patients with chronic schizophrenia, thereby providing a scientific basis for early identification and intervention of insomnia in this population.

METHODS

From May to December 2018, 317 patients with chronic schizophrenia were included. General demographic data were collected using a self-administered questionnaire. Insomnia, psychotic symptoms, and depression were assessed using a series of validated scales. Additionally, plasma levels of lipid metabolism parameters and inflammatory cytokines, including interleukin (IL)-1β, IL-6, IL-17 A, and tumor necrosis factor-α (TNF-α), were measured. Finally, logistic regression analysis was conducted to identify the independent predictors of insomnia symptoms.

RESULTS

Among patients with chronic schizophrenia, 42.3% exhibited insomnia symptoms. Univariate analyses revealed that, compared to the non-insomnia group, patients in insomnia group were older and had higher positive symptom scores, higher general psychopathology scores, higher total scores on the Calgary Depression Scale (CDSS), and elevated plasma levels of Log IL-6 (all p < 0.05). Furthermore, regression analyses identified age (OR = 1.027, 95% CI = 1.005-1.048, p = 0.013), CDSS total score (OR = 1.265, 95% CI = 1.163-1.375, p < 0.001), and Log IL-6 level (OR = 2.053, 95% CI = 1.251-3.371, p = 0.004) as independent correlates of insomnia.

CONCLUSION

Patients with chronic schizophrenia are at a relatively high risk of developing insomnia. Insomnia symptoms may be associated with age, psychotic symptoms, depressive symptoms, and elevated levels of IL-6. Based on these findings, clinical staff should enhance the monitoring and assessment of sleep quality in patients with chronic schizophrenia and implement targeted early interventions for those at risk of insomnia.