Endocrine Abstracts

Introduction: Poorly-controlled hypothyroidism is frequently associated with sleep disorders such as impaired sleep quality and obstructive sleep apnea. The aim of this study was to evaluate the sleep quality in patients with well-controlled primary hypothyroidism.

Methods: This was a single-center, cross-sectional study including 50 patients with well-controlled primary hypothyroidism (TSH level within the normal range: 0.35-4.94 mIU/l) for at least one year. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Sleep disturbance was defined by a score greater than 5.

Results: The study included 45 women and 5 men with a mean age of 55 ± 12.5 years. Hypothyroidism was secondary to Hashimoto’s thyroiditis, thyroidectomy, and radioactive iodine treatment in 70%, 16%, and 8% of cases, respectively. Its median duration was 10.4 years. Mean sleep duration was 7.3 ± 1.8 hours/day, with no significant difference between women and men. The mean PSQI score was 7.6 ± 4. This score was not correlated with TSH level and levothyroxine dose. Sleep disorders were diagnosed in 34 patients (68%). Seventy-four percent of patients had daytime sleepiness.

Conclusion: Sleep disturbances are common even in patients with well-controlled hypothyroidism. Screening and adequate management of these disorders would improve the quality of life of patients with primary hypothyroidism.