Chronic Insomnia Disorder: Co-occurrence Patterns of Inflammation and Cognitive Alterations

ObjectiveThis study aimed to investigate the co-occurrence patterns of inflammatory, carotid atherosclerotic, MRI-based brain atrophy-related, and cognitive alterations in patients with Chronic Insomnia Disorder (CID), with a focus on exploring the statistical association of IL-6 with insomnia severity and cognitive function.

MethodsA total of 88 patients with chronic insomnia and 60 healthy controls underwent physical examinations between May 2024 and April 2025. Insomnia severity was assessed using the Athens Insomnia Scale (AIS). Serum levels of white blood cell count (WBC), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and lipid profiles were measured using automated hematology and biochemistry analyzers. Carotid intima-media thickness (CIMT) and plaque incidence were evaluated via color Doppler ultrasound. Brain morphological changes were examined using magnetic resonance imaging (MRI), and global cognitive function was assessed with the Mini-Mental State Examination (MMSE).

ResultsThe chronic insomnia group had significantly higher levels of hs-CRP, IL-6, homocysteine, and triglycerides, and lower levels of high-density lipoprotein compared to the control group. Both CIMT and carotid plaque incidence were higher in the chronic insomnia group. The frontal lobe b/i ratio was slightly higher, but the difference was not statistically significant. Significant differences were found in the cerebellar a/h ratio, temporal lobe e/k ratio, average hippocampal width, average sulcal width, and MMSE scores.

Pearson analysis showed that IL-6 and triglyceride levels were positively correlated with AIS scores and negatively correlated with MMSE scores. The exploratory path model indicated a significant positive association between triglyceride levels and AIS scores.