A comparative cross-sectional study on sleep quality in patients with a history of differentiated thyroid carcinoma and its correlation with quality of life

Purpose: To evaluate sleep quality in differentiated thyroid carcinoma (DTC) patients and correlate sleep disturbances with quality of life (QoL). Methods: 119 DTC patients were enrolled (DTC group). The Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI) inventories were administered. The Thyroid-specific Patient-Reported Outcome (ThyPRO) questionnaire, the Billewicz scale (BS) and an ad-hoc visual analogic scale (VAS) were used to measure QoL and subjective therapy-related complaints. The same examinations were conducted in 53 subjects (control group) who had undergone surgery for benign thyroid pathology. Results: L-T4 dosages and TSH levels differed between the groups. BS and VAS scores were comparable. PSQI documented a similar percentage of poor sleepers in the DTC (74%) and control (62%) groups. ISI showed no difference in subjects without clinically significant insomnia: DTC (43%) and controls (48%). ThyPRO showed significantly worse scores in DTC than control subjects. In DTC patients, PSQI (P = 0.002) and ISI (P = 0.04) correlated significantly with age. In control subjects, TSH displayed a significant positive association with PSQI (P = 0.02) and ISI (P < 0.05). The ThyPRO general score correlated significantly with PSQI in DTC patients. In both groups, ISI correlated significantly with several ThyPRO scales and the ThyPRO general score. “Anxiety” and “emotional susceptibility” were the scales most significantly related with PSQI and ISI. Conclusion: In disease-free DTC patients and subjects who undergo thyroid surgery for benign pathology, abnormal sleep components and insomnia are similar. The ThyPRO questionnaire closely reflects sleep disturbances in all subjects. Recognising and treating sleep disturbances might improve QoL.