Wu Tiejian, Flowers Joanne W, Tudiver Fred, Wilson Jim L, Punyasavatsut Natavut
Department of Public Health, East Tennessee State University, Johnson City, TN 37614, USA.
BMC Pediatr. 2006 Apr 19;6:12. doi: 10.1186/1471-2431-6-12.
Thyroid hormone plays a crucial role in the growth and function of the central nervous system. The purpose of the study was to examine the relationships between the status of subclinical thyroid conditions and cognition among adolescents in the United States.
Study sample included 1,327 adolescents 13 to 16 years old who participated in the Third National Health and Nutrition Examination Survey (NHANES III). Serum thyroxine (T4) and thyroid stimulating hormone (TSH) were measured and subclinical hypothyroidism, subclinical hyperthyroidism, and euthyroid groups were defined. Cognitive performance was assessed using the subscales of the Wide Range Achievement Test-Revised (WRAT-R) and the Wechsler Intelligence Scale for Children-Revised (WISC-R). The age-corrected scaled scores for arithmetic, reading, block design, and digit span were derived from the cognitive assessments.
Subclinical hypothyroidism was found in 1.7% and subclinical hyperthyroidism was found in 2.3% of the adolescents. Cognitive assessment scores on average tended to be lower in adolescents with subclinical hyperthyroidism and higher in those with subclinical hypothyroidism than the score for the euthyroid group. Adolescents with subclinical hypothyroidism had significantly better scores in block design and reading than the euthyroid subjects even after adjustment for a number of variables including sex, age, and family income level.
Subclinical hypothyroidism was associated with better performance in some areas of cognitive functions while subclinical hyperthyroidism could be a potential risk factor.
甲状腺激素在中枢神经系统的生长和功能中起着至关重要的作用。本研究的目的是探讨美国青少年亚临床甲状腺疾病状态与认知之间的关系。
研究样本包括1327名13至16岁的青少年，他们参加了第三次全国健康和营养检查调查（NHANES III）。测量血清甲状腺素（T4）和促甲状腺激素（TSH），并定义亚临床甲状腺功能减退、亚临床甲状腺功能亢进和甲状腺功能正常组。使用修订后的广泛成就测验（WRAT-R）和修订后的韦氏儿童智力量表（WISC-R）的子量表评估认知表现。从认知评估中得出算术、阅读、积木设计和数字广度的年龄校正量表分数。
1.7%的青少年存在亚临床甲状腺功能减退，2.3%的青少年存在亚临床甲状腺功能亢进。亚临床甲状腺功能亢进的青少年认知评估得分平均往往低于甲状腺功能正常组，而亚临床甲状腺功能减退的青少年得分则高于甲状腺功能正常组。即使在对包括性别、年龄和家庭收入水平在内的多个变量进行调整后，亚临床甲状腺功能减退的青少年在积木设计和阅读方面的得分仍显著高于甲状腺功能正常的受试者。
亚临床甲状腺功能减退与某些认知功能领域的较好表现相关，而亚临床甲状腺功能亢进可能是一个潜在风险因素。
