Fig. 1Serum thyroid stimulating hormone (TSH) and free thyroxine (fT4) levels by age and sex. (A) Geometric mean TSH levels (mIU/L) by age. (B) Mean fT4 levels (ng/dL) by age. A U-shaped association was found between serum TSH levels and age. TSH levels were significantly higher in women than in men (P<0.001). Serum fT4 levels significantly decreased with age (P for trend <0.0001), and were significantly higher in men than in women (P<0.0001). Adapted from Park et al. [6].
Fig. 2Relationship of urinary iodine concentration (UIC) with serum thyroid stimulating hormone (TSH) levels. A U-shaped curve was found between age and serum TSH levels, with lower levels in middle-aged adults and higher levels in younger and older age groups. A U-shaped curve was also detected for the relationship between age and UIC. Therefore, changes in serum TSH levels with age may be influenced by changes in UIC in the Korean population. Adapted from Park et al. [6].
Fig. 3Urinary iodine concentration (UIC, µg/L) by age and sex. According to the World Health Organization recommendations, only 23% of subjects were in the adequate range (UIC, 100 to 199 µg/L), and 65% were classified as having an intake that was above requirements (UIC 200 to 299 µg/L) or excessive (UIC ≥300 µg/L). However, 12% had insufficient iodine intake (UIC <100 µg/L). The median UIC was higher in school-aged children (6 to 12 years) and in the above 70 years age group than in other age groups. Adapted from Park et al. [6].
Table 1Prevalence of TPOAb in the Korean Population According to Age and Sex
Age, yr |
All, % |
Men, % |
Women, % |
10–18 |
2.81 |
2.12 |
3.73 |
19–29 |
4.13 |
3.27 |
5.23 |
30–39 |
5.63 |
2.76 |
9.08 |
40–49 |
7.94 |
4.22 |
12.54 |
50–59 |
11.71 |
5.97 |
17.78 |
60–69 |
10.01 |
7.71 |
11.80 |
≥70 |
3.13 |
3.13 |
3.14 |
All ages |
7.30 |
4.33 |
10.62 |
Table 2Prevalence of Hyperthyroidism and Hypothyroidism in Korea: Comparison of KNHANES VI Data with HIRA Data
|
Kim et al. [5] |
Seo et al. [2324] |
Publication |
Endocrinol Metab (Seoul) 2017;32:106-14 |
J Korean Thyroid Assoc 2013;6:56-63 |
Endocrinol Metab (Seoul) 2015;30:288-96 |
Data source |
KNHANES VI |
HIRA |
Inclusion |
Individuals who were not receiving treatment |
Subclinical patients receiving overtreatment |
Exclusion |
Well-controlled euthyroid patients with treatment |
Individuals who were not receiving treatment |
Prevalence |
|
|
Hyperthyroidism |
|
|
Overt |
0.54% (men, 0.30%; women, 0.81%) |
0.34% (men, 0.20%; women, 0.47%) |
Subclinical |
2.98% (men, 2.43%; women, 3.59%) |
|
Hypothyroidism |
|
|
Overt |
0.73% (men, 0.40%; women, 1.10%) |
1.43% (men, 0.44%; women, 2.40%) |
Subclinical |
3.10% (men, 2.26%; women, 4.04%) |
|