title: Reference intervals of thyroid hormones in a previously iodine-deficient but presently more than adequate area of Western China: a population-based survey.
abstract: The aim of our study is to establish the reference intervals (RIs) of thyroid hormones in a previously iodine-deficient area but presently more than iodine-adequate area of Western China, and also to investigate the factors which affect thyroid function. The cross-sectional study conducted in Xi'an, was based on 2007-2008 China National Diabetes and Metabolic Disorders Survey. Among 1286 participating adults, 717 were finally included as reference population. Thyrotropin (TSH), total triiodothyronine (T3), free triiodothyronine (FT3), total thyroxine (T4), free thyroxine (FT4), thyroperoxidase antibody (TPO-Ab) and thyroglobulin antibody (Tg-Ab) were measured. Thyroid ultrasound examination was also performed. The present study established the new RIs of serum TSH (0.43-5.51 mIU/L), FT4 (11.0-20.4 pmol/L), FT3 (3.63-5.73 pmol/L), T4 (67.8-157 mmol/L) and T3 (1.08-2.20 mmol/L), which were different from the data provided by the manufacturers. Significant differences among all the age groups were observed in FT3, but neither in TSH nor in FT4. The TSH levels in adults with pathologic ultrasonography results or positive thyroid autoantibody were significantly higher than those in reference adults. Our present results provide valuable references for the diagnosis of thyroid diseases in population of Western China. Considering that most inland areas of China have faced the challenge of the transition from iodine deficiency to adequacy or more than adequacy, we recommend physicians utilize our RIs to determine thyroid diseases in the similar areas with Xi'an in China.
authors: Department of Endocrinology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Jing
authors: J
authors: Cai
authors: Yujie
authors: Y
authors: Fang
authors: Da
authors: D
authors: Jing
authors: Shaoyong
authors: S
authors: Xu
authors: Jie
authors: J
authors: Ming
authors: Bin
authors: B
authors: Gao
authors: Han
authors: H
authors: Shen
authors: Rong
authors: R
authors: Zhang
authors: Qiuhe
authors: Q
authors: Ji
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000453:epidemiology / Q000534:rehabilitation*; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage; D011795:Surveys and Questionnaires; D013960:Thyroid Function Tests / Q000592:standards*; D013963:Thyroid Hormones / Q000097:blood*; D055815:Young Adult
chemical_list: D017673:Sodium Chloride, Dietary; D013963:Thyroid Hormones; C034024:iodized salt; D007455:Iodine