Prevalence of abnormal thyroid function test and significance of TSH in health examination.

Jung, Sang Won; Chang, Sang Yoo; Cho, Jung Jin

Original Article

Journal of the Korean Academy of Family Medicine 1993;14(11):752-759.
Published online November 1, 1993.

Prevalence of abnormal thyroid function test and significance of TSH in health examination.

Sang Won Jung, Sang Yoo Chang, Jung Jin Cho

건강검진에서 갑상선자극호르몬 측정의 의의와 갑상선 기능이상자의 유병율

조정진, 정상유, 정상원

한일병원 가정의학과

Abstract

Background
: TSH is of great use as screening test in health examination. Recently, new sensitive EIA has been developed. We calculated normal range of TSH and positive predictive value of TFT abnormality by this method. Also, this study was carried out for the purpose of presuming the prevalence of TFT abnormality in community screening test of our county.

Methods : TSH levels were measured in 4,708 subjects that participated in periodic health examination at department of family medicine, Hanil hospital. The subjects with TSH abnormality were carried out test of T3 and T4.

Results : There were 4,649 men and 59 women in study population. According to area, subjects were distributed to 1,935 in rural area, 1,651 in small and medium cities and 1,122 in large cities. The number of subjects with TSH abnormality was 123 (2.6%) and the number of subjects with TFT abnomality among male was 32(0.7%). There was no statistically difference by age and sex, there was revealed as statistically significant higher rate in small and medium cities by area. The TSH was revealed as left skewed distribution. The normal ragne of TSH was 0.34~3.28mIU/L after log transformation and positive predictive value was 26%. After supposing sensitivity was 100%, specificity was etimated as 98.1%.

Conclusion : The prevalence of T3, T4 abnormality in Korea as similar as other countries was 0.7% and positive predictive value of T3, T4 abnormality by EIA methods was 26% that was low. Therefore it seems that there are restrictions in cost effectiveness as community screening test, although sensitivity and specificity were high.

초록

연구배경 : 갑상선자극호르몬은 건강검진에서 갑상선질환의 선별검사로 유용하게 사용되고 있다. 최근 저농도의 갑상선자극호르몬 측정에 민감한 효소면역 측정법이 개발되었다. 저자들은 이 방법을 통하여 갑상선호르몬의 이상치에 대한 양성예측율을 구하고 정상구간을 산정하였다. 또한 우리나라의 집단선별검사에서 갑상선기능이상자의 유병율을 추정하고자 본 연구를 시행하였다.

방법 : 1992년 3월부터 1992년 4월까지 한일병원 가정의학과에서 실시된 정기강점진에 참여한 일개 국영기업체 직원중 4708명을 대상으로 갑상선자극호르몬을 측정하고, 이상자에 한해 갑상선호르몬을 측정하였다.

결과 : 전 대상자 4708명중 남자는 4649명, 여자는 59명였으며 지역별 분포로는 지방이 1935명, 중소도시 1651명, 대도시 1122명 였다. TSH 이상자는 123명으로 2.6%였고, 남자 대상자중 T3, T4 이상자중 32명으로 0.7%였다. T3, T4 이상자는 연령, 성별에 따라 차이가 없었고 지역별로는 중소도시에서 통계학적으로 의미있게 많았다. TSH는 왼쪽으로 치우친 분포를 보이며 로그변환후 산출한 정상치의 한계는 0.34~3.28mIU/L 였고 양성예측율은 26%였다. 민감도를 100%로 가정후 특이도를 산출한 값이 98.1%였다.

결론 : 우리나라 청장년층 남자에서 T3, T4 이상자의 비율은 외국의 남성갑상선기능 이상자의 비율보다 높은 분포를 나타냈으며 효소면역측정법의 양성예측율은 26%로 낮아 민감도와 특이도가 높다해도 집단선별검사로서의 비용효과면에서는 약간의 제한점을 가지고 있는 것으로 보인다.