Baskoy Kamil, Ay Seyid Ahmet, Altundag Aytug, Kurt Onuralp, Salihoglu Murat, Deniz Ferhat, Tekeli Hakan, Yonem Arif, Hummel Thomas
Department of Endocrinology and Metabolism, Haydarpaşa Training Hospital, Gulhane Military Medical School, Istanbul, Turkey.
Department of Otorhinolaryngology, Istanbul Surgery Hospital, Istanbul, Turkey.
PLoS One. 2016 Feb 29;11(2):e0149979. doi: 10.1371/journal.pone.0149979. eCollection 2016.
Subclinical hypothyroidism has been accused for coronary heart disease, lipid metabolism disorders, neuropsychiatric disorders, infertility or pregnancy related problems with various strength of evidence. Currently there is insufficient knowledge about olfaction and taste functions in subclinical hypothyroidism. Aim of the present study is to investigate the degree of smell and taste dysfunction in patients with subclinical hypothyroidism. 28 subclinical hypothyroid patients, and 31 controls enrolled in the prospective study in Istanbul, Turkey. Subclinical hypothyroid patients were treated with L-thyroxine for 3 months. Psychophysiological olfactory testing was performed using odor dispensers similar to felt-tip pens ("Sniffin' Sticks", Burghart, Wedel, Germany). Taste function tests were made using "Taste Strips" (Burghart, Wedel, Germany) which are basically tastant adsorbed filter paper strip. Patients scored lower on psychophysical olfactory tests than controls (odor thresholds:8.1±1.0 vs 8.9±1.1, p = 0.007; odor discrimination:12.4±1.3 vs 13.1±0.9, p = 0.016; odor identification:13.1±0.9 vs 14.0±1.1, p = 0.001; TDI score: 33.8±2.4 vs 36.9±2.1, p = 0.001). In contrast, results from psychophysical gustatory tests showed only a decreased score for "bitter" in patients, but not for other tastes (5.9±1.8 vs 6.6±1.0, p = 0.045). Three month after onset of treatment olfactory test scores already indicated improvement (odor thresholds:8.1±1.0 vs 8.6±0.6, p<0.001; odor discrimination:12.4±1.31 vs 12.9±0.8, p = 0.011; odor identification:13.1±0.9 vs 13.9±0.8, p<0.001; TDI scores:33.8±2.4 vs 35.5±1.7, p<0.001) respectively. Taste functions did not differ between groups for sweet, salty and, sour tastes but bitter taste was improved after 3 months of thyroxin substitution (patients:5.9±1.8 vs 6.6±1.2, p = 0.045). Correlation of changes in smell and taste, with thyroid function test were also evaluated. TSH, fT4 were found have no correlation with smell and taste changes with treatment. However bitter taste found positively correlated with T3 with treatment(r: 0.445, p: 0.018). Subclinical hypothyroid patients exhibited a significantly decreased olfactory sensitivity; in addition, bitter taste was significantly affected. Most importantly, these deficits can be remedied on average within 3 months with adequate treatment.
亚临床甲状腺功能减退已被指与冠心病、脂质代谢紊乱、神经精神疾病、不孕或妊娠相关问题存在不同程度的关联证据。目前，关于亚临床甲状腺功能减退患者的嗅觉和味觉功能的了解尚不充分。本研究的目的是调查亚临床甲状腺功能减退患者嗅觉和味觉功能障碍的程度。28例亚临床甲状腺功能减退患者和31名对照者纳入了在土耳其伊斯坦布尔进行的前瞻性研究。亚临床甲状腺功能减退患者接受左甲状腺素治疗3个月。使用类似于毡尖笔的气味分配器（“嗅棒”，德国韦德尔市布尔哈特公司）进行心理生理学嗅觉测试。味觉功能测试使用“味觉试纸”（德国韦德尔市布尔哈特公司），其本质上是吸附有味物质的滤纸。患者在心理生理学嗅觉测试中的得分低于对照组（气味阈值：8.1±1.0对8.9±1.1，p = 0.007；气味辨别：12.4±1.3对13.1±0.9，p = 0.016；气味识别：13.1±0.9对14.0±1.1，p = 0.001；TDI评分：33.8±2.4对36.9±2.1，p = 0.001）。相比之下，心理生理学味觉测试结果显示，患者仅在“苦味”方面得分降低，其他味道则未降低（5.9±1.8对6.6±1.0，p = 0.045）。治疗开始3个月后，嗅觉测试得分已显示出改善（气味阈值：8.1±1.0对8.6±0.6，p<0.001；气味辨别：12.4±1.31对12.9±0.8，p = 0.011；气味识别：13.1±0.9对13.9±0.8，p<0.001；TDI评分：33.8±2.4对35.5±1.7，p<0.001）。甜味、咸味和酸味的味觉功能在各组之间没有差异，但甲状腺素替代治疗3个月后苦味有所改善（患者：5.9±1.8对6.6±1.2，p = 0.045）。还评估了嗅觉和味觉变化与甲状腺功能测试的相关性。发现促甲状腺激素（TSH）、游离甲状腺素（fT4）与治疗后的嗅觉和味觉变化无相关性。然而，发现苦味与治疗后的三碘甲状腺原氨酸（T3）呈正相关（r：0.445，p：0.018）。亚临床甲状腺功能减退患者表现出明显降低的嗅觉敏感性；此外，苦味受到显著影响。最重要的是，通过适当治疗，这些缺陷平均可在3个月内得到纠正。
