title: [Reference interval of serum thyroid hormones in healthy Korean adults].
abstract: OBJECTIVE
  This study was conducted to determine the reference interval of serum thyroid hormones (TSH, FT3, FT4) in healthy Korean adults.
  
  
  METHODS
  Health examination data from 1,591 healthy Korean adults who visited an university hospital were analyzed. Patients with specific health conditions capable of altering laboratory results were excluded from the study. Serum thyroid hormones were measured using IMMULITE 2000 (DPC, USA, 2002). Subjects were 18-65 years old; 911 were male, and 690 were female.
  
  
  RESULTS
  The arithmetic means of TSH, FT3, and FT4 values for male subjects were 1.28+/-1.84 microIU/ml, 3.23+/-0.57 pg/ml, and 1.42+/-0.22 ng/dl, respectively. In female subjects, the arithmetic means of TSH, FT3, and FT4 values were 1.49+/-2.08 microIU/ml, 3.08+/-0.54 pg/ml, and 1.29 +/-0.24 ng/dl, respectively. The arithmetic mean FT4 value for males decreased with age (p<0.01). The arithmetic mean FT3 value for females increased with age (p<0.01). The arithmetic mean thyroid hormone values of all study subjects differed significantly based on season. The arithmetic mean of male FT4 decreased with increasing BMI (p<0.01). The arithmetic mean of female FT3 increased with increasing BMI (p<0.01). The reference intervals recommended by the IMMULITE 2000 manufacturer are 0.40-4.00 microIU/ml for TSH, 1.80-4.20 pg/ml for FT3, and 0.80-1.90 ng/dl for FT4 (same values for both genders).
  
  
  CONCLUSIONS
  There was a significant difference in the interval of thyroid hormones between males and females, but the reference interval of IMMULITE 2000 was not established by gender. There is a need to reestablish the reference interval for thyroid hormones in Korean healthy adults.
authors.affiliation: Department of Health, Graduate School of Environment & Public Health Studies, Yeungnam University, Korea.
authors.forename: Yoon-Young
authors.initials: YY
authors.lastname: Jang
authors.forename: Chang-Yoon
authors.initials: CY
authors.lastname: Kim
authors.forename: Tae-Yoon
authors.initials: TY
authors.lastname: Hwang
authors.forename: Kyung-Dong
authors.initials: KD
authors.lastname: Kim
authors.forename: Chae-Hoon
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D012959:Socioeconomic Factors; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine