Thyroid Hormone Levels and TSH Activity in Patients with Obstructive Sleep Apnea Syndrome

Area of Science:

• Sleep Medicine
• Endocrinology

Background:

• Obstructive sleep apnea syndrome (OSAS) involves breathing disruptions during sleep.
• Hypothyroidism is a rare but recognized cause of OSAS, sometimes improving with thyroid hormone replacement.
• However, achieving euthyroid status in OSAS patients doesn't always resolve breathing issues, often necessitating continuous positive airway pressure (CPAP).

Purpose of the Study:

• To investigate the prevalence of thyroid dysfunction in patients diagnosed with severe obstructive sleep apnea syndrome.
• To explore potential correlations between thyroid function tests and OSAS severity markers.

Main Methods:

• A cohort of 813 patients with severe OSAS (mean apnea-hypopnea index of 44.0) was analyzed.
• Thyroid function was assessed using thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) levels.
• Data included anthropometric measurements (BMI) and polysomnography results.

Main Results:

• Hypothyroidism was diagnosed in 4.7% and hyperthyroidism in 3.8% of the OSAS patients.
• No significant correlations were found between TSH, fT3, or fT4 levels and anthropometric data or polysomnography results.
• The incidence of thyroid dysfunction in this OSAS cohort was comparable to the general population.

Conclusions:

• The prevalence of thyroid function disorders in patients with severe OSAS is not elevated compared to the general population.
• No association was identified between thyroid-stimulating hormone levels and the severity of breathing disturbances during sleep in these patients.