ASSESSING THYROID FUNCTION IN OBSTRUCTIVE SLEEP APNEA (OSA) PATIENTS: A CORRELATION WITH SLEEP SEVERITY PARAMETERS

Abstract

Background:
Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder caused by upper airway obstruction, leading to repeated episodes of apnea and hypopnea during sleep. It is frequently associated with cardiovascular, metabolic, and endocrine disturbances, including thyroid dysfunction. Hypothyroidism may contribute to the pathogenesis of OSA by altering upper airway muscle tone and respiratory drive. Early detection of thyroid abnormalities in OSA patients can aid in improving clinical outcomes and reducing symptom burden.

Objective:
To determine the frequency of thyroid dysfunction in patients with obstructive sleep apnea and its association with the severity of OSA.

Methods:
A descriptive cross-sectional study was conducted in the Chest Medicine Ward, Pulmonology Department, Jinnah Postgraduate Medical Centre, Karachi, from June to December 2024. Sixty-seven newly diagnosed OSA patients aged 18–60 years were recruited using non-probability consecutive sampling. Diagnoses were confirmed by overnight polysomnography, and thyroid function was evaluated using blood levels of TSH, FT3, and FT4. Demographic, anthropometric, and clinical data were recorded using a structured proforma. Statistical analysis was performed using SPSS version 25, with significance set at p ≤ 0.05.

Results:
The mean age of participants was 51.8 ± 6.4 years, with 74.6% being female. Mean BMI was 30.2 ± 4.9 kg/m². The mean apnea, hypopnea, and AHI were 29.3 ± 32.7, 30.8 ± 14.8, and 28.0 ± 11.1 episodes/hour, respectively. Severity of OSA was mild in 22.4%, moderate in 16.4%, and severe in 61.2% of cases. Thyroid function revealed euthyroid status in 89.6%, overt hypothyroidism in 7.5%, and subclinical hypothyroidism in 3.0%. No significant correlation was found between thyroid disease and OSA severity.

Conclusion:
Thyroid dysfunction was infrequent among OSA patients, and no significant association was observed with disease severity. Screening for thyroid disorders may be more beneficial in high-risk or symptomatic individuals rather than routine testing in all OSA cases.