TY - JOUR T1 - Determination of thyrotropin reference values in an adult Mexican population JO - Endocrinología y Nutrición (English Edition) T2 - AU - Flores-Rebollar,Armando AU - Moreno-Castañeda,Lidia AU - Vega-Servín,Norman S. AU - López-Carrasco,Guadalupe AU - Ruiz-Juvera,Aída SN - 21735093 M3 - 10.1016/j.endoen.2015.01.001 DO - 10.1016/j.endoen.2015.01.001 UR - https://www.elsevier.es/en-revista-endocrinologia-nutricion-english-edition--412-articulo-determination-thyrotropin-reference-values-in-S2173509315000021 AB - Background and objectiveThe upper limit of TSH reference level is controversial. The purpose of our study was to determine TSH reference values in a Mexican population in accordance with the National Academy of Clinical Biochemistry (NACB) criteria and in correlation with thyroid ultrasound (US) examination. Patients and methodsThe study was conducted in volunteers with no known thyroid disease. We recruited 482 subjects, most of them medical or administrative staff from our hospital. They answered a questionnaire on demographic data, family history, co-morbidities, and drug use. Their thyroid hormone levels and thyroid antibodies were determined, and a complete physical examination and thyroid US were performed. The population used to establish the TSH reference intervals was selected according to the NACB criteria and their normal thyroid structural and echogenic characteristics in US examination. ResultsAmong 482 subjects (209 males) with a median age of 26 years, prevalence rates of TPOAb and TgAb were 9.3% and 10.3% respectively. Mean TSH level in the overall population was 1.90±1.94, with a 97.5th percentile of 6.76mIU/L. The reference population was limited to 282 subjects (41.5% were excluded) with a mean TSH of 1.86±1.63 and a 97.5th percentile of 4.88mIU/L. No sex difference was found (p=0.287). Median urinary iodine level in the reference population was 267μg/L IQR (161.3–482.5). ConclusionsThe TSH reference interval in the reference population was 0.71 (CI 0.65–0.77) to 4.88mIU/L (CI 4.5–5.3); these limits may be influenced by iodine nutritional status in this population. ER -