Lindeman Robert D, Romero Linda J, Schade David S, Wayne Sharon, Baumgartner Richard N, Garry Philip J
Department of Internal Medicine, School of Medicine, and Aging and Genetic Epidemiology Program, Health Science Center, University of New Mexico, Albuquerque, New Mexico 87131-5666, USA.
Thyroid. 2003 Jun;13(6):595-600. doi: 10.1089/105072503322238863.
The serum/plasma total homocysteine (tHcy) concentration, now recognized as an independent risk factor for accelerated atherosclerotic disease, is increased in overtly hypothyroid patients, and it decreases with thyroid replacement therapy. Whether or not individuals with subclinical hypothyroidism also increase their tHcy concentrations, and whether this elevation might help to explain the increased prevalence of the atherosclerotic diseases observed in this condition, remains unclear. If individuals with subclinical hypothyroidism have higher tHcy concentrations than euthyroid subjects, there would be added incentive to treat this condition earlier. In this cross-sectional study (New Mexico Elder Health Survey) of a randomly selected sample of Medicare recipients (age > or =65 years), no significant difference in serum tHcy concentrations could be detected between the 112 participants with subclinical hypothyroidism (Groups 2 and 3) and the 643 participants with thyrotropin (TSH) values < or =4.6 microU/mL (Group 1) after adjusting for differences in gender, ethnicity, age, and serum concentrations of folate, vitamin B(12), and creatinine. Only those participants with the highest TSH levels (>10 microU/mL) (Group 3) had a significantly higher prevalence of coronary heart disease (CHD) when compared against Group 1 participants (p = 0.007). No consistent significant differences in the prevalences of CHD or in the CHD risk factors examined were observed when all participants with subclinical hypothyroidism (Groups 2 and 3 combined) were compared against Group 1 participants.
血清/血浆总同型半胱氨酸（tHcy）浓度现已被公认为加速动脉粥样硬化疾病的独立危险因素，在明显甲状腺功能减退的患者中升高，且随甲状腺替代治疗而降低。亚临床甲状腺功能减退的个体tHcy浓度是否也会升高，以及这种升高是否有助于解释在这种情况下观察到的动脉粥样硬化疾病患病率增加，目前尚不清楚。如果亚临床甲状腺功能减退的个体tHcy浓度高于甲状腺功能正常的受试者，那么就会更有动力更早治疗这种疾病。在这项针对随机选取的医疗保险受益人群（年龄≥65岁）的横断面研究（新墨西哥州老年人健康调查）中，在对性别、种族、年龄以及叶酸、维生素B12和肌酐的血清浓度差异进行校正后，112名亚临床甲状腺功能减退参与者（第2组和第3组）与643名促甲状腺激素（TSH）值≤4.6微单位/毫升的参与者（第1组）之间，血清tHcy浓度未检测到显著差异。只有那些TSH水平最高（>10微单位/毫升）的参与者（第3组）与第1组参与者相比，冠心病（CHD）患病率显著更高（p = 0.007）。当将所有亚临床甲状腺功能减退的参与者（第2组和第3组合并）与第1组参与者进行比较时，未观察到冠心病患病率或所检查的冠心病危险因素存在一致的显著差异。
