ArticlePloS one2018
Age- and gender-specific reference intervals of TSH and free T4 in an iodine-replete area: Data from Korean National Health and Nutrition Examination Survey IV (2013-2015).
Article in PloS one, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers, 2 of them syntheses that pooled it.
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Who cites it
41 citing papers in PubMed, 2 syntheses or guidelines pooled it, 82 citations in OpenAlex.
- Factors influencing the reference interval of thyroid-stimulating hormone in healthy adults: A systematic review and meta-analysis.Clinical endocrinology · 2021Pooled it
- The Impact of Shift-Work and Night Shift-Work on Thyroid: A Systematic Review.International journal of environmental research and public health · 2020Pooled it
- Article
- Age-specific TSH reference limits and early levothyroxine effects in postmenopausal women with subclinical hypothyroidism: a prospective cohort study in Vietnam.BMC endocrine disorders · 2026Article
- Revisiting the TSH range in older adults: associations between subclinical hypothyroidism and geriatric conditions.Journal of the Endocrine Society · 2026Article
- Stability-aware LSTM-MPC framework for personalized levothyroxine dosing in Hashimoto's thyroiditis.Frontiers in endocrinology · 2026Article
- Comparison of thyroid hormones reference intervals based on thyroid antibody levels: A multicenter study.PloS one · 2026Article
- Thyroid Hormone Sensitivity as a Possible Determinant of Metabolic Phenotypes in Young Adults, Not in Older Individuals.The Journal of clinical endocrinology and metabolism · 2025Article
- Lower FT3 levels are associated with a poor prognosis in patients with acute type A aortic dissection: a retrospective study.European journal of medical research · 2025Article
- Changes in Thyroid Function and Autoimmunity in Older Individuals: Longitudinal Analysis of the Whickham Cohort.The Journal of clinical endocrinology and metabolism · 2025Article
- Incidence and Risk Factors for Amiodarone-Induced Thyroid Dysfunction: A Nationwide Retrospective Cohort Study.American journal of cardiovascular drugs : drugs, devices, and other interventions · 2025Article
- Assessing thyroid health: phenotypic age compared to chronological age.Frontiers in endocrinology · 2025Article
- Clinical Implications of Different Thyroid-Stimulating Hormone (TSH) Reference Intervals between TSH Kits for the Management of Subclinical Hypothyroidism.Endocrinology and metabolism (Seoul, Korea) · 2024Article
- Is There an Adequate Therapeutic Approach to Thyroid Pathology in Patients with Down Syndrome?Diagnostics (Basel, Switzerland) · 2023Article
- Management of Subclinical Hypothyroidism: A Focus on Proven Health Effects in the 2023 Korean Thyroid Association Guidelines.Endocrinology and metabolism (Seoul, Korea) · 2023Article
- Covariance regression with random forests.BMC bioinformatics · 2023Article
- Automatic Levothyroxine Dosing Algorithm for Patients Suffering from Hashimoto's Thyroiditis.Bioengineering (Basel, Switzerland) · 2023Article
- Reference intervals for thyroid hormones for the elderly population and their influence on the diagnosis of subclinical hypothyroidism.Journal of medical biochemistry · 2023Article
- A masquerade in a symptomatic patient with heart failure.Malaysian family physician : the official journal of the Academy of Family Physicians of Malaysia · 2023Article
- Indirect estimation of reference intervals for thyroid parameters using advia centaur XP analyzer.Journal of medical biochemistry · 2022Article
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Authors and funding
8 authors at 2 institutions in 1 country.
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No grant is acknowledged in the PubMed record.
Abstract
backgroundEstablishment of the reference interval of thyroid-stimulating hormone (TSH) is critical in the diagnosis of thyroid dysfunction and is affected by age, gender, iodine nutrition, and ethnicity. The aim of this study was to determine the reference intervals of TSH and free thyroxin (FT4) from a large, nationwide data of Korea where iodine intake is more than adequate.
methodsWe analyzed data from the Korea National Health and Nutrition Examination Survey VI that measured serum TSH, FT4, and thyroid peroxidase antibody from 7,061 individuals (urinary iodine measurement in 6,565). Age- and gender-specific reference intervals were established from 95% confidence limits from the 2.5 to 97.5 percentile of TSH (log-transformed) and FT4 in reference populations.
resultsThe geometric mean of TSH was 2.16 ± 0.01 mIU/L, with the lowest value found in the middle aged group (2.04 ± 0.02 mIU/L) and higher values noted in age groups of 10-19 and over 70 years (2.38 ± 0.02 and 2.32 ± 0.07 mIU/L, respectively). The association of TSH and age was U-shaped. The overall reference interval of TSH was 0.59-7.03 mIU/L. Mean FT4 was 1.25 ± 0.003 ng/dL (16.09 ± 0.039 pmol/L), and it showed a small but continuous decrease after 20 years of age (P < 0.001). There was a significant positive correlation between TSH and urine iodine concentration (r = 0.154, P < 0.001).
conclusionsThe reference interval of TSH in Korea, where iodine intake is above the requirement, was 0.59-7.03 mIU/L and showed U-shaped change with age, which was a similar pattern to iodine intake. The reference interval of FT4 was 0.92-1.60 ng/dL. The geometric mean and upper limit of TSH were higher than those of Western populations, reflecting the paramount importance of iodine intake on thyroid function.
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