Xiaodan Zhai1, Le Zhang1, Lulu Chen2, Xiaolan Lian3, Chao Liu4, Bingyin Shi5, Lixin Shi6, Nanwei Tong7, Shu Wang8, Jianping Weng9, Jiajun Zhao10, Xiaochun Teng11, Xiaohui Yu11, Yaxin Lai11, Weiwei Wang11, Chenyan Li11, Jinyuan Mao11, Yongze Li11, Chenling Fan11, Ling Li1, Zhongyan Shan11, Weiping Teng11. 1. Department of Endocrinology, Shengjing Affiliated Hospital of China Medical University, Shenyang, P.R. China. 2. Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China. 3. Department of Endocrinology, Beijing Union Medical College Hospital, Beijing, P.R. China. 4. Department of Endocrinology, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, P.R. China. 5. Department of Endocrinology, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi'an, P.R. China. 6. Department of Endocrinology, Affiliated Hospital of Guiyang Medical College, Guiyang, P.R. China. 7. Department of Endocrinology, West China hospital, Sichuan University, Chengdu, P.R. China. 8. Department of Endocrinology, The Ruijin Hospital of Shanghai Jiaotong University, Shanghai, P.R. China. 9. Department of Endocrinology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, P.R. China. 10. Department of Endocrinology, The Provincial Hospital Affiliated to Shandong University, Jinan, P.R. China. 11. Department of Endocrinology and Metabolism, Key Laboratory of Endocrine Diseases in Liaoning Province, The First Hospital of China Medial University, Shenyang, P.R. China.
Abstract
Background: The fact that serum thyrotropin (TSH) levels increase with age may influence the diagnosis of thyroid diseases in older adults. This study aimed to establish an age-specific serum TSH reference range, examine the prevalence of thyroid diseases in older adults ≥65 years, and analyze the risk factors. Methods: A cross-sectional study of adult populations in 10 cities in China was conducted from 2010 to 2011. A total of 15,008 subjects were randomly selected and completed the present study. Urinary iodine concentration, serum TSH, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) titers were measured. Thyroid ultrasonography and questionnaires were completed by all the subjects. When the TSH level was abnormal, free thyroxine and/or free triiodothyronine levels were measured. Results: When the reference range of the general population was used, the prevalence rates of overt hypothyroidism (Ohypo) and subclinical hypothyroidism (Shypo) in older adults ≥65 years were significantly higher than those in younger adults <65 years (2.09% vs. 0.80% and 19.87% vs. 16.23%, respectively; p < 0.001). Positive TPOAb and positive TgAb were associated with the prevalence of Shypo in older adults. An age-specific serum TSH reference range was formulated according to guidelines set forth by the National Academy of Clinical Biochemistry. Both the median and upper limit values of serum TSH in older adults were higher than those in younger adults (2.58 [0.75-8.86] mIU/L vs. 2.38 [0.76-6.57] mIU/L; p < 0.001). Using the age-specific serum TSH reference range, the prevalence of Shypo in older adults was 3.3%, which was significantly lower than the prevalence based on the reference range of the general population (3.3% vs. 19.87%). The prevalence rates of Ohypo, overt hyperthyroidism (Ohyper), and subclinical hyperthyroidism (Shyper) did not change much (Ohypo: 1.6% vs. 2.09%; Ohyper: 0.7% vs. 0.52%; and Shyper: 3.8% vs. 0.73%). Positive TPOAb, but not positive TgAb, was also associated with the prevalence of Shypo as diagnosed with the age-specific serum TSH reference range. Conclusion: The serum TSH level increases with age, which may represent a normal compensatory phenomenon in older adults ≥65 years. To prevent misdiagnosis and mistreatment, the use of an age-specific serum TSH reference range is recommended in older adults for the diagnosis of thyroid diseases.
Background: The fact that serum thyrotropin (TSH) levels increase with age may influence the diagnosis of thyroid diseases in older adults. This study aimed to establish an age-specific serum TSH reference range, examine the prevalence of thyroid diseases in older adults ≥65 years, and analyze the risk factors. Methods: A cross-sectional study of adult populations in 10 cities in China was conducted from 2010 to 2011. A total of 15,008 subjects were randomly selected and completed the present study. Urinary iodine concentration, serum TSH, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) titers were measured. Thyroid ultrasonography and questionnaires were completed by all the subjects. When the TSH level was abnormal, free thyroxine and/or free triiodothyronine levels were measured. Results: When the reference range of the general population was used, the prevalence rates of overt hypothyroidism (Ohypo) and subclinical hypothyroidism (Shypo) in older adults ≥65 years were significantly higher than those in younger adults <65 years (2.09% vs. 0.80% and 19.87% vs. 16.23%, respectively; p < 0.001). Positive TPOAb and positive TgAb were associated with the prevalence of Shypo in older adults. An age-specific serum TSH reference range was formulated according to guidelines set forth by the National Academy of Clinical Biochemistry. Both the median and upper limit values of serum TSH in older adults were higher than those in younger adults (2.58 [0.75-8.86] mIU/L vs. 2.38 [0.76-6.57] mIU/L; p < 0.001). Using the age-specific serum TSH reference range, the prevalence of Shypo in older adults was 3.3%, which was significantly lower than the prevalence based on the reference range of the general population (3.3% vs. 19.87%). The prevalence rates of Ohypo, overt hyperthyroidism (Ohyper), and subclinical hyperthyroidism (Shyper) did not change much (Ohypo: 1.6% vs. 2.09%; Ohyper: 0.7% vs. 0.52%; and Shyper: 3.8% vs. 0.73%). Positive TPOAb, but not positive TgAb, was also associated with the prevalence of Shypo as diagnosed with the age-specific serum TSH reference range. Conclusion: The serum TSH level increases with age, which may represent a normal compensatory phenomenon in older adults ≥65 years. To prevent misdiagnosis and mistreatment, the use of an age-specific serum TSH reference range is recommended in older adults for the diagnosis of thyroid diseases.
Authors: Jeong Mi Kim; Bo Hyun Kim; Hyungi Lee; Eun Heui Kim; Mijin Kim; Jong Ho Kim; Yun Kyung Jeon; Sang Soo Kim; In Joo Kim; Yong Ki Kim Journal: Diabetes Metab J Date: 2019-04-03 Impact factor: 5.376