Endocrinol Metab.  2017 Mar;32(1):106-114. 10.3803/EnM.2017.32.1.106.

Thyroid Stimulating Hormone Reference Range and Prevalence of Thyroid Dysfunction in the Korean Population: Korea National Health and Nutrition Examination Survey 2013 to 2015

• Kim WG
• Kim WB
• Woo G
• Kim H
• Cho Y
• Kim TY
• Kim SW
• Shin MH
• Park JW
• Park HL
• Oh K
• Chung JH

• KMID: 2413294
• DOI: http://doi.org/10.3803/EnM.2017.32.1.106

Abstract

BACKGROUND
No nationwide epidemiological study evaluating the prevalence of subclinical and overt forms of hypothyroidism and hyperthyroidism has yet been conducted in Korea. This study aimed to evaluate the reference range of serum thyroid stimulating hormone (TSH) and the national prevalence of thyroid dysfunctions in Korea.
METHODS
Nation-wide cross-sectional data were analyzed from a representative sample of the civilian, non-institutionalized Korean population (n=6,564) who underwent blood testing for thyroid function and anti-thyroid peroxidase antibody (TPOAb) as part of the Korea National Health and Nutrition Examination Survey VI (2013 to 2015).
RESULTS
The reference interval of serum TSH in the Korean reference population was 0.62 to 6.68 mIU/L. Based on this reference interval, the prevalence of overt and subclinical hypothyroidism was 0.73% (males 0.40%, females 1.10%) and 3.10% (males 2.26%, females 4.04%), respectively. The prevalence of hypothyroidism increased with age until the age group between 50 to 59 years. Positive TPOAb were found in 7.30% of subjects (males 4.33%, females 10.62%). The prevalence of overt and subclinical hypothyroidism TPOAb-positive subjects was 5.16% and 10.88%, respectively. The prevalence of overt and subclinical hyperthyroidism was 0.54% (males 0.30%, females 0.81%) and 2.98% (males 2.43%, females, 3.59%), respectively.
CONCLUSION
The Serum TSH reference levels in the Korean population were higher than the corresponding levels in Western countries. Differences were found in the prevalence of hypothyroidism and hyperthyroidism according to age, sex, and TPOAb positivity. This study provides important baseline information for understanding patterns of thyroid dysfunction and diseases in Korea.

Keyword

Thyrotropin; Hypothyroidism; Hyperthyroidism; Prevalence; Thyroid gland

MeSH Terms

Epidemiologic Studies
Female
Hematologic Tests
Humans
Hyperthyroidism
Hypothyroidism
Korea*
Nutrition Surveys*
Peroxidase
Prevalence*
Reference Values*
Thyroid Gland*
Thyrotropin*
Peroxidase
Thyrotropin

Figure

• 

  Fig. 1 Prevalence of overt and subclinical thyroid dysfunction according to age and gender in Korea. (A) Prevalence of overt hypothyroidism and (B) subclinical hypothyroidism. (C) Prevalence of overt hyperthyroidism and (D) subclinical hyperthyroidism.

• 

  Fig. 2 Prevalence of subjects with positive anti-thyroid peroxidase antibody (TPOAb) results according to age and gender in Korea.

Reference

1. Cooper DS. Subclinical hypothyroidism. JAMA. 1987; 258:246–247.

2. Biondi B, Cooper DS. The clinical significance of subclinical thyroid dysfunction. Endocr Rev. 2008; 29:76–131.

3. Kim YA, Park YJ. Prevalence and risk factors of subclinical thyroid disease. Endocrinol Metab (Seoul). 2014; 29:20–29.

4. Aghini-Lombardi F, Antonangeli L, Martino E, Vitti P, Maccherini D, Leoli F, et al. The spectrum of thyroid disorders in an iodine-deficient community: the Pescopagano survey. J Clin Endocrinol Metab. 1999; 84:561–566.

5. Laurberg P, Pedersen KM, Hreidarsson A, Sigfusson N, Iversen E, Knudsen PR. Iodine intake and the pattern of thyroid disorders: a comparative epidemiological study of thyroid abnormalities in the elderly in Iceland and in Jutland, Denmark. J Clin Endocrinol Metab. 1998; 83:765–769.

6. O'Leary PC, Feddema PH, Michelangeli VP, Leedman PJ, Chew GT, Knuiman M, et al. Investigations of thyroid hormones and antibodies based on a community health survey: the Busselton thyroid study. Clin Endocrinol (Oxf). 2006; 64:97–104.

7. Sawin CT, Castelli WP, Hershman JM, McNamara P, Bacharach P. The aging thyroid. Thyroid deficiency in the Framingham Study. Arch Intern Med. 1985; 145:1386–1388.

8. Hollowell JG, Staehling NW, Flanders WD, Hannon WH, Gunter EW, Spencer CA, et al. Serum TSH, T(4), and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). J Clin Endocrinol Metab. 2002; 87:489–499.

9. Bagchi N, Brown TR, Parish RF. Thyroid dysfunction in adults over age 55 years. A study in an urban US community. Arch Intern Med. 1990; 150:785–787.

10. Canaris GJ, Manowitz NR, Mayor G, Ridgway EC. The Colorado thyroid disease prevalence study. Arch Intern Med. 2000; 160:526–534.

11. Teng W, Shan Z, Teng X, Guan H, Li Y, Teng D, et al. Effect of iodine intake on thyroid diseases in China. N Engl J Med. 2006; 354:2783–2793.

12. Parle JV, Franklyn JA, Cross KW, Jones SC, Sheppard MC. Prevalence and follow-up of abnormal thyrotrophin (TSH) concentrations in the elderly in the United Kingdom. Clin Endocrinol (Oxf). 1991; 34:77–83.

13. Boekholdt SM, Titan SM, Wiersinga WM, Chatterjee K, Basart DC, Luben R, et al. Initial thyroid status and cardiovascular risk factors: the EPIC-Norfolk prospective population study. Clin Endocrinol (Oxf). 2010; 72:404–410.

14. Surks MI, Hollowell JG. Age-specific distribution of serum thyrotropin and antithyroid antibodies in the US population: implications for the prevalence of subclinical hypothyroidism. J Clin Endocrinol Metab. 2007; 92:4575–4582.

15. Spencer CA, Hollowell JG, Kazarosyan M, Braverman LE. National Health and Nutrition Examination Survey III thyroid-stimulating hormone (TSH)-thyroperoxidase antibody relationships demonstrate that TSH upper reference limits may be skewed by occult thyroid dysfunction. J Clin Endocrinol Metab. 2007; 92:4236–4240.

16. Cho NH, Choi HS, Kim KW, Kim HL, Lee SY, Choi SH, et al. Interaction between cigarette smoking and iodine intake and their impact on thyroid function. Clin Endocrinol (Oxf). 2010; 73:264–270.

17. Guan H, Shan Z, Teng X, Li Y, Teng D, Jin Y, et al. Influence of iodine on the reference interval of TSH and the optimal interval of TSH: results of a follow-up study in areas with different iodine intakes. Clin Endocrinol (Oxf). 2008; 69:136–141.

18. Surks MI, Boucai L. Age- and race-based serum thyrotropin reference limits. J Clin Endocrinol Metab. 2010; 95:496–502.

19. Knudsen N, Bulow I, Jorgensen T, Laurberg P, Ovesen L, Perrild H. Comparative study of thyroid function and types of thyroid dysfunction in two areas in Denmark with slightly different iodine status. Eur J Endocrinol. 2000; 143:485–491.

20. Bulow Pedersen I, Knudsen N, Jorgensen T, Perrild H, Ovesen L, Laurberg P. Large differences in incidences of overt hyper- and hypothyroidism associated with a small difference in iodine intake: a prospective comparative register-based population survey. J Clin Endocrinol Metab. 2002; 87:4462–4469.

21. Baloch Z, Carayon P, Conte-Devolx B, Demers LM, Feldt-Rasmussen U, Henry JF, et al. Laboratory medicine practice guidelines. Laboratory support for the diagnosis and monitoring of thyroid disease. Thyroid. 2003; 13:3–126.

22. Kim M, Kim TY, Kim SH, Lee Y, Park SY, Kim HD, et al. Reference interval for thyrotropin in a ultrasonography screened Korean population. Korean J Intern Med. 2015; 30:335–344.

23. Seo GH, Chung JH. Incidence and prevalence of overt hypothyroidism and causative diseases in Korea as determined using claims data provided by the Health Insurance Review and Assessment Service. Endocrinol Metab (Seoul). 2015; 30:288–296.

24. Seo GH, Kim SW, Chung JH. Incidence & prevalence of hyperthyroidism and preference for therapeutic modalities in Korea. J Korean Thyroid Assoc. 2013; 6:56–63.

25. Ministry of the Interior. Seegene Medical Foundation, Laboratory Medicine of the Korea National Health and Nutrition Examination Survey VI (2013–2015) [Internet]. Seoul: Centers for Disease Control and Prevention;2015. updated 2015 Dec 18. cited 2017 Jan 23. Available from: http://www.prism.go.kr/homepage/entire/retrieveEntireDetail.do?pageIndex=1&research_id=1351000-201500293&leftMenuLevel=160&cond_research_name=%EC%A7%84%EB%8B%A8%EC%9D%98%ED%95%99%EA%B2%80%EC%82%AC&cond_research_start_date=&cond_research_end_date=&pageUnit=10&cond_order=3.

26. Hollowell JG, Staehling NW, Hannon WH, Flanders DW, Gunter EW, Maberly GF, et al. Iodine nutrition in the United States. Trends and public health implications: iodine excretion data from National Health and Nutrition Examination Surveys I and III (1971-1974 and 1988-1994). J Clin Endocrinol Metab. 1998; 83:3401–3408.

27. Caldwell KL, Miller GA, Wang RY, Jain RB, Jones RL. Iodine status of the U.S. population, National Health and Nutrition Examination Survey 2003-2004. Thyroid. 2008; 18:1207–1214.

28. Choi HS, Park YJ, Kim HK, Choi SH, Lim S, Park DJ, et al. Prevalence of subclinical hypothyroidism in two population based-cohort: Ansung and KLoSHA cohort in Korea. J Korean Thyroid Assoc. 2010; 3:32–40.