A study on factors related to sleep disorders and serum BDNF expression levels in patients with primary Sjögren's syndrome.

Objectives: We aimed to assess the sleep quality of patients with primary Sjögren's syndrome (pSS) and the associated factors. Moreover, we conducted a preliminary exploration of the clinical significance of serum brain-derived neurotrophic factor (BDNF) in pSS patients with sleep disorders.

Methods: A self-report survey was administered to 111 pSS patients and 40 healthy individuals using the Pittsburgh Sleep Quality Index for sleep quality. Clinical data, and mental conditions were collected using on-site questionnaires and various scales. A total of 40 healthy controls from the health examination centre of the same hospital, who were age- and sex-matched. Detection of serum BDNF levels by enzyme-linked immunosorbent assay method. Use GraphPad Prism to analyze data and create graphs.

Results: Patients with pSS had higher scores on the Pittsburgh Sleep Quality Index than the healthy individuals. Abnormal sweating, high Patient Health Questionnaire-9 and EULAR Sjögren Syndrome Patient Reported Index scores were independent risk factors for sleep disorders. pSS patients had lower serum BDNF than the healthy individuals. The area under the curve of predicting sleep disorder in pSS patients using detection of serum BDNF level was 0.8470, and the sensitivity and specificity were 0.951 and 0.727, which were superior to Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7.

Conclusion: Compared with the healthy individuals, pSS patients had a higher prevalence of sleep disorders and lower serum BNDF. Serum BDNF level demonstrated greater predictive advantage for sleep disorder in pSS patients.