Importance and Necessity of Thyroid Function Tests in the Pre-Diagnosis of Obstructive Sleep Apnea

Objective: Obstructive sleep apnea syndrome (OSAS); is a clinical condition that presented with non-specific symptoms that are frequently seen in hypothyroidism such as snoring, daytime sleepiness, excess weight, apathy and / or lethargy. In this respect, it is important that the differential diagnosis is made carefully with hypothyroidism. Material and Methods: We retrospectively reviewed the data of 309 patients who underwent all night PSG test with pre-diagnosis of sleeping breathing disorders. Demographic data, body mass index, PSG scores and thyroid function test results were evaluated. Results: The mean age of all cases was 38.46 ± 12.34 and the body mass index (BMI) was 28.14 ± 4.08. Of all cases 279 (90.3%) were male and 30 (9.7%) were female. 91 (29.45%) cases had AHI <5 and defined as non-OSAS group. Mild, moderate and severe OSAS were determined in 80 (25.89%) patients, 60 (19.42%) patients and 78 (25.24%) patients, respectively (Table 1). When thyroid function tests were examined for entire group, hypothyroidism was detected in 16 cases (5.59%). Of these 5 were in the group without OSAS and 11 were in the group with OSAS. Hypothyroidism frequency was 6.17% in the non-OSAS group and 5.36% in the OSAS diagnosed group. Conclusion: Our results demonstrated that 50% of the cases with hypothyroidism were in the non-OSAS and mild OSAS group, necessitating the evaluation of thyroid functions. Thyroid function tests, an easily applicable screening method, is clinically important and necessary in patients presenting with OSAS-like symptoms