한국 신생아의 혈중 갑상선자극 홀몬(TSH)치에 관한 연구

Abstract

[한글]

신생아의 혈중 Thyroid stimulating hormone(TSH)치는 생후 30분내지 1시간에 급격히 상승하였다가 서서히 감소하여 출생후 경과시간에 따라 정상 TSH치가 다르다는 것이 알려졌다. 또 지능박약의 한 원인인 선천성 갑상선기능저하증을 조기발견하여 치료하기 위해서는 신생아기의 screening test가 필요하나 우리나라에서는 아직 시행되지 않으며 신생아기의 정상 TSH치도 잘 알려져 있지 않다.

이에 저자는 1984년 11월부터 1986년 2월까지 순천향병원에서 분만된 신생아 567명을 대상으로 Filter paper blood spot을 이용한 방사면역측정법으로 그 일령별 TSH치를 측정하여 다음과 같은 결과를 얻었다.

1) 567명의 신생아중 남아가 303례, 여아가 264례이었고 이들의 혈중 TSH치는 각각 2.16μU/ml, 2.26μU/ml로 차이가 없었다(p>0.05).

2) 일령에 따른 신생아의 평균 TSH치는 생후 1일이 3.39μU/ml, 2일 3.21μU/ml, 3일 2.03μU/ml, 4일 0.8μU/ml, 5∼7일 0.99μU/ml, 8-10일 0.80μU/ml, 11-24일에는 0.47μU/ml로 생후 1일에 제일 높고 점차 감소하였다.

3) 전반적으로 미숙아의 T5H치는 만삭아에 비해 낮았으나 통계학적인 의의는 없었고(p>0.05), 두 군에서 모두 생후 1일에 제일 높고 점차 감소하였다.

4) 혈중 TSH치는 분만방식에 따라서는 별 차이가 없었다(p>0.05).

5) 567례중 357례 (63.0%)에서 TSH치가 1.0μU/ml이하였고 558례 (98.4%)에서 20μU/ml 이하였다.

6) 생후 1일에는 95.4%, 2일에 97.2%, 3일에는 99.2%에서 TSH치가 20μU/ml이하였고 생후 4일 이후에는 100%에서 10μU/ml 이하였다.

7) 첫 검사에서 TSH치가 20μU/ml이상인 경우는 9례 (1.6%)로 모두 생후 3일이내에 검사하였고 재검시에 전례에서 5μU/ml이하로 떨어졌다.

8) Screening test중 1례에서 선천성 갑상선기능저하증이 발견되었다.

본 연구의 결과로서 신생아기의 TSH screening test는 생후 3일 이후에 실시하고 TSH치의 한계치는 20μU/ml로 하는 것이 적절하다고 생각된다.

[영문]

The thyroid stimulating hormone (TSH) assay is a valuable technique used for the early detection of congenital hypothyroidism, main cause of mental retardation.

Until recently this test had not been widely used in Korea. Consequently normal values of TSH for neonates have not been established. The purpose of this study is to determine normal levels of TSH during the neonatal period, note any differences

due to the method of delivery, the age or the sex of the infants, and to define the optimum conditions for performing a TSH assay.

Five hundred and sixty seven neonates were grouped according to age (the 1st, the 2nd, the 3rd, the 4th, the 5-7th, the 8-lOth and above the 11th day of life) : and TSH concentration was measured by TSH radioimmunoassay using filter paper blood spots.

The following results are obtained:

1. The mean values of TSH were 2.16μU/ml in males and 2.26μU/ml in females, which had no significant difference(p>0.05).

2. The mean TSH concentrations in neonates based on age groups were 3.39μU/ml in the 1st day of life, 3.21μU/ml in the 2nd day of life, 2.03μU/ml in the 3rd day of life, 0.81μU/ml in the 4th day of life, 0.99μU/ml in the 5-7th day of life, 0.80μU/ml in the 8-lOth day of life and 0.47μU/ml in the 11-24th day of life.

The value of TSH was highest on the 1st day of life and gradually decreased.

3. The mean TSH concentration in premature infants was lower than that of term babies(p>0.05) and it was highest on the 1st day of Life and then decreased gradually in both groups.

4. There was no significant difference of TSH concentrations due to the method of delivery.

5. The value of TSH was Less than 1.0μU/ml in 63.0% of the total cases and less than 20.0μU/ml in 98.4% of the total cases.

6. The percent of cases with a TSH concentration less than 20.0μU/ml was 95.4% on the 1st day of life, 97.2% on the 2nd day of life, 99.2% on the 3rd day of life and 100% after the 4th day of life. TSH concentration then decreased to less than 10.0μU/ml.

7. Nine neonates (1.6%) with an initial TSH level of greater than 20.0μU/ml were retested following the 7th day of life. In each case the TSH level was within normal levels (less than 5.0μU/ml).

8. One case of congenital hypothyroidism due to dyshormonogenesis was diagnosed.

In conclusions the TSH concentration on the 3rd day of life is the best parameter for screening purposes with 20.0μU/ml considered to be the upper limit of normal.