Harsini Asma Rajabi, Mohajeri-Tehrani Mohammad Reza, Sajjadi-Jazi Sayed Mahmoud, Naeini Fatemeh, Valisoltani Neda, Sadeghi Erfan, Mohammadi Hamed, Hosseini Saeed
Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
Clin Nutr ESPEN. 2024 Jun;61:71-78. doi: 10.1016/j.clnesp.2024.02.030. Epub 2024 Mar 13.
It is unclear whether variation in thyroid stimulating hormone (TSH) levels within the reference range affect energy expenditure and clinical symptoms and even within the normal range of TSH levels, resting energy expenditure may alter. The aim of the present study was to determine whether treated hypothyroid subjects and healthy subjects with a low-normal TSH range (0.3-2.3 mIU/L) have better clinical outcomes and increased energy expenditure than those with a high-normal TSH range (2.3-4.3 mIU/L).
This was a case-control study of 160 overweight/obese women with TSH levels across the reference range of 0.3-4.3 mU/l. Subjects were paired in four groups: healthy subjects with low-normal target TSH (n = 40), healthy subjects with high-normal target TSH (n = 40), subjects with treated hypothyroidism with low-normal target TSH (n = 40), and subjects with treated hypothyroidism with high-normal target TSH (n = 40). Resting energy expenditure (RMR), dietary intake, body composition, physical activity, and biochemical markers were assessed.
Subjects with low-normal (≤2.3 mU/L) and high-normal (>2.3 mU/L) TSH levels did not differ in terms of RMR, serum T3 levels, and clinical symptoms except fatigue (P = 0.013). However, serum fT4 levels were found to be significantly different between the study groups (P = 0.002). Serum fT4 concentration was the highest in subjects with treated hypothyroidism with low-normal target TSH.
Variation in serum TSH levels within the reference range did not significantly affect REE and clinical symptoms except fatigue in healthy and women with hypothyroidism.
尚不清楚促甲状腺激素（TSH）水平在参考范围内的变化是否会影响能量消耗和临床症状，甚至在TSH水平的正常范围内，静息能量消耗也可能发生改变。本研究的目的是确定接受治疗的甲状腺功能减退患者和TSH范围处于低正常水平（0.3 - 2.3 mIU/L）的健康受试者，与TSH范围处于高正常水平（2.3 - 4.3 mIU/L）的受试者相比，是否具有更好的临床结局和更高的能量消耗。
这是一项病例对照研究，研究对象为160名超重/肥胖女性，其TSH水平在0.3 - 4.3 mU/l的参考范围内。受试者被分为四组：TSH目标值为低正常水平的健康受试者（n = 40）、TSH目标值为高正常水平的健康受试者（n = 40）、TSH目标值为低正常水平的接受治疗的甲状腺功能减退受试者（n = 40）以及TSH目标值为高正常水平的接受治疗的甲状腺功能减退受试者（n = 40）。评估静息能量消耗（RMR）、饮食摄入量、身体成分、身体活动和生化指标。
TSH水平处于低正常（≤2.3 mU/L）和高正常（>2.3 mU/L）的受试者在RMR、血清T3水平和临床症状方面（除疲劳外）无差异（P = 0.013）。然而，研究组之间血清游离T4（fT4）水平存在显著差异（P = 0.002）。血清fT4浓度在TSH目标值为低正常水平的接受治疗的甲状腺功能减退受试者中最高。
在健康女性和甲状腺功能减退女性中，血清TSH水平在参考范围内的变化除疲劳外，未显著影响静息能量消耗（REE）和临床症状。
