O S Khraisha, M M Al-Madani, A N Peiris, T K Paul
Department of Medicine, Mountain Home Veterans Administration Medical Center, East Tennessee State University at Johnson City, TN.
J La State Med Soc. 2015 Mar-Apr;167(2):47-9. Epub 2015 Apr 15.
Hypothyroidism is easily treated by levothyroxine therapy which has an 80 percent absorption rate, mostly in the jejunum. The replacement dose of daily levothyroxine is usually calculated at 1.6 mcg/kg body weight per day. We report a 77-year-old man who required supraphysiologic thyroxine replacement (>2.7 mcg/ kg/day) to treat his hypothyroidism. The patient was referred for persistent thyroid stimulating hormone (TSH) elevation (40 mcIU/ml) while on 175 mcg of levothyroxine. Patient was compliant with medication. Medical history included diabetes mellitus type 2, cerebrovascular accident, depression, hypertension, hyperlipidemia, atherosclerotic cardiovascular disease, vitamin B12 deficiency, Addison’s disease, as well as a colostomy secondary to diverticulitis. He was taking aspirin, carvedilol, cholecalciferol, finasteride, fluoxetine, furosemide, ketoconazole, levothyroxine, prednisone, and albuterol/ipratropium inhaler. His height was 180.3 cm; weight, 107 kg. Thyroid was impalpable, and he was clinically euthyroid. Despite discontinuation of iron and statin which are known to interfere with thyroxine absorption and crushing of thyroxine tablets to enhance absorption, his TSH remained elevated. Celiac disease and Helicobacter pylori infection were ruled out with serological testing. There was no proteinuria and anti-parietal cell antibody was positive. Gastroparesis was confirmed by gastric emptying study. He continued to require increasing doses of thyroxine with increment to 300 mcg daily. To our knowledge, this is the first documented association between gastroparesis and thyroxine malabsorption. We recommend that gastroparesis be considered in any patient with persistent TSH elevation despite usual thyroxine doses.
甲状腺功能减退症通过左甲状腺素治疗很容易得到控制，其吸收率达80%，主要在空肠吸收。左甲状腺素的每日替代剂量通常按每天每千克体重1.6微克来计算。我们报告了一名77岁男性，他需要超生理剂量的甲状腺素替代治疗（>2.7微克/千克/天）来治疗甲状腺功能减退症。该患者在服用175微克左甲状腺素时，因促甲状腺激素（TSH）持续升高（40毫国际单位/毫升）前来就诊。患者服药依从性良好。病史包括2型糖尿病、脑血管意外、抑郁症、高血压、高脂血症、动脉粥样硬化性心血管疾病、维生素B12缺乏症、艾迪生病，以及因憩室炎继发的结肠造口术。他正在服用阿司匹林、卡维地洛、胆钙化醇、非那雄胺、氟西汀、呋塞米、酮康唑、左甲状腺素、泼尼松，以及沙丁胺醇/异丙托溴铵吸入剂。他身高180.3厘米，体重107千克。甲状腺无法触及，临床检查甲状腺功能正常。尽管停用了已知会干扰甲状腺素吸收的铁剂和他汀类药物，并将甲状腺素片碾碎以提高吸收，但他的TSH仍持续升高。血清学检测排除了乳糜泻和幽门螺杆菌感染。无蛋白尿，抗壁细胞抗体呈阳性。胃排空研究证实存在胃轻瘫。他继续需要增加甲状腺素剂量，增至每日300微克。据我们所知，这是胃轻瘫与甲状腺素吸收不良之间首次有文献记载的关联。我们建议，对于任何尽管使用常规剂量甲状腺素但TSH仍持续升高的患者，都应考虑胃轻瘫的可能。
