睡眠時無呼吸症候群患者における甲状腺機能の検討

Thyroid function in sleep apnea syndrome

はじめに

　甲状腺機能低下症は，睡眠時無呼吸症候群（sleep apnea syndrome：SAS）を合併する頻度が有意に高いことが知られている^1）。一方，SASにおいて甲状腺機能低下症を合併する割合は1％程度と報告されており^2），睡眠時無呼吸症候群の全例に甲状腺機能スクリーニングを行う必要性については意見が定まっていない。今回われわれは，睡眠時無呼吸症候群が疑われ，終夜睡眠ポリグラフ検査（polysomnography：PSG）を施行した症例における甲状腺機能を評価し，その相関について検討したので報告する。

　We investigated the relationship between thyroid function and sleep apnea. Eighty subjects who were suspected to have sleep apnea syndrome（SAS）were enrolled. They were 60 men and 20 women, ranging from 21 to 82 years in age with an average of 53.1 years. They underwent polysomnography to examine apnea indices such as apnea hypopnea index, blood oxygen saturation decline index, minimum blood oxygen saturation, maximum apnea time, and average apnea time. Serum TSH, free T3, and free T4 were concomitantly measured. There was no significant correlation between any of the apnea indices and the thyroid function indices. These results suggest that the checkup of the thyroid function is not routinely required for the management of SAS.