Takeuchi Shoko, Kitamura Takuro, Ohbuchi Toyoaki, Koizumi Hiroki, Takahashi Risa, Hohchi Nobusuke, Suzuki Hideaki
Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan.
Sleep Breath. 2015 Mar;19(1):85-9. doi: 10.1007/s11325-014-0966-0. Epub 2014 Mar 13.
Sleep apnea is sometimes associated with hypothyroidism, but the significance of thyroid function screening in sleep apnea patients has been controversial. In the present study, we investigated the relationship between thyroid function and sleep apnea in subjects who were suspected to have sleep apnea.
We enrolled 156 consecutive subjects suspected of having sleep apnea. Subjects included 117 men and 39 women aged 21 to 84 years. They underwent nocturnal multichannel polysomnography during a one-night hospitalization. The examined indices of sleep apnea were apnea-hypopnea index (AHI), lowest oxygen saturation, oxygen desaturation index, longest apnea duration, mean apnea duration, and the percent of apnea time to sleep time. Serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were concomitantly measured by electrochemiluminescence immunoassays.
Three subjects (1.9 %) were diagnosed with primary hypothyroidism (high TSH and low FT4), and one subject (0.6 %) with subclinical hypothyroidism (high TSH and normal FT4). No significant difference in the level of TSH, FT3, or FT4 was seen among subjects with different severity of sleep apnea. The mean apnea duration significantly correlated with TSH in both simple and multiple regression analyses. Subjects with lower FT3 (≤3.75 pg/ml) showed longer mean apnea time compared to those with higher FT3 (>3.75 pg/ml) (24.9 ± 0.8 vs. 20.2 ± 1.2 s; P = 0.009). The other indices of sleep apnea did not show significant correlation with thyroid function.
These results suggest that the mean apnea duration and TSH/FT3 may be helpful in understanding reciprocity between the two disease states, and for evaluating the validity of thyroid function tests in patients with sleep apnea.
睡眠呼吸暂停有时与甲状腺功能减退有关，但甲状腺功能筛查在睡眠呼吸暂停患者中的意义一直存在争议。在本研究中，我们调查了疑似患有睡眠呼吸暂停的受试者甲状腺功能与睡眠呼吸暂停之间的关系。
我们连续纳入了156名疑似患有睡眠呼吸暂停的受试者。受试者包括117名男性和39名女性，年龄在21至84岁之间。他们在住院一晚期间接受了夜间多导睡眠监测。睡眠呼吸暂停的检查指标包括呼吸暂停低通气指数（AHI）、最低血氧饱和度、氧饱和度下降指数、最长呼吸暂停持续时间、平均呼吸暂停持续时间以及呼吸暂停时间占睡眠时间的百分比。同时通过电化学发光免疫分析法测定血清促甲状腺激素（TSH）、游离三碘甲状腺原氨酸（FT3）和游离甲状腺素（FT4）。
3名受试者（1.9%）被诊断为原发性甲状腺功能减退（TSH升高且FT4降低），1名受试者（0.6%）被诊断为亚临床甲状腺功能减退（TSH升高且FT4正常）。在不同严重程度的睡眠呼吸暂停患者中，TSH、FT3或FT4水平未见显著差异。在简单和多元回归分析中，平均呼吸暂停持续时间与TSH均显著相关。FT3较低（≤3.75 pg/ml）的受试者与FT3较高（>3.75 pg/ml）的受试者相比，平均呼吸暂停时间更长（24.9±0.8 vs. 20.2±1.2秒；P = 0.009）。睡眠呼吸暂停的其他指标与甲状腺功能未见显著相关性。
这些结果表明，平均呼吸暂停持续时间和TSH/FT3可能有助于理解这两种疾病状态之间的相互关系，并有助于评估睡眠呼吸暂停患者甲状腺功能检查的有效性。
