Abstract: Objectives To investigate the association between sleep disturbance and thyroid function in maintenance hemodialysis (MHD) patients. Methods This was a single-center and cross-sectional study. Patients regularly undergoing maintenance hemodialysis at the Blood Purification Center in Guangzhou Red Cross Hospital of Jinan University in November 2023 were enrolled. Demographic data, pre-dialysis laboratory parameters, medication history were collected, and pre-dialysis serum samples were collected for thyroid function tests. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Results  In total, 126 patients were enrolled, with 65 (51.6%) patients in the normal sleep group and 61 (48.4%) patients in the sleep disturbance group. Univariate binary logistic regression showed that continuous variables including lower serum free triiodothyronine (FT3) levels (OR=0.332,95% CI:0.178～0.620, P=0.001) and longer dialysis vintage (OR=1.018, 95% CI:1.007～1.030,P=0.001), as well as categorical variables including FT3 ＜3.4 pmol/L (OR=3.201,95% CI:1.222～8.390, P=0.018) and use of sleep medications (OR=5.658,95% CI:2.310～13.861,P＜0.001) were all associated with sleep disturbance. However, there was no significant association between serum free thyroxine, thyroid-stimulating hormone levels, and sleep disturbance. After adjusted for age, sex, dialysis vintage, Kt/V, and use of sleep medications, the multivariate binary logistic regression showed serum FT3＜3.4 pmol/L (OR=3.225，95% CI:1.229～8.464，P=0.017) was still associated with sleep disturbance. Conclusion Lower serum FT3 levels and sleep disturbance were independently associated in MHD patients. However, prospective studies are needed to confirm the results. 

Key words: Chronic kidney disease, Maintenance hemodialysis, Free triiodothyronine, Sleep disturbance, Pittsburgh sleep quality index