Table of Contents

Locator Record

Title: Thyroid Profile (THYROD_E )
Contact Number: 1-866-441-NCHS
Years of Content: 2007 - 2008
First Published: September, 2009
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:The Thyroid Profile consists of a battery of several tests for the measurement of thyroid function including Total and Free Thyroxine, Total and Free Triiodothyronine, Thyroglobulin, Thyroglobulin Antibodies, Thyroid Peroxidase Antibodies, and Thyroid Stimulating Hormone.
Record Source: NHANES 2007 - 2008
Survey Methodology: NHANES 2007 - 2008 is a stratified multistage probability sample of the civilian non-institutionalized population of the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

The Thyroid Profile consists of a battery of several tests for the measurement of thyroid function, including Total and Free Thyroxine, Total and Free Triiodothyronine, Thyroglobulin, Thyroglobulin Antibodies, Thyroid Peroxidase Antibodies, and Thyroid Stimulating Hormone. Thyroid function is crucial for maintaining normal metabolic function in adults and for proper neurological development of the fetus. Serum levels will be used to assess thyroid function and will provide population-based reference information on these hormone levels

Eligible Sample

Participants aged 12 years and older, who do not meet any of the exclusion criteria, are eligible.

 

Description of Laboratory Methodology

Thyroid blood specimens were processed, stored and shipped to University of Washington, Seattle, WA. Detailed specimen collection and processing instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM).

Thyroid-stimulating hormone

The Access HYPERsensitive human thyroid-stimulating hormone (hTSH) assay is a 3rd generation, two-site immunoenzymatic (“sandwich”) assay. A sample is added to a reaction vessel with goat anti-hTSH-alkaline phosphatase conjugate, buffered protein solution, and paramagnetic particles coated with immobilized mouse monoclonal anti-hTSH antibody. (Goat anti-mouse antibody is used to immobilize the mouse anti-hTSH antibody.) The hTSH binds to the immobilized monoclonal anti-hTSH on the solid phase while the goat anti-hTSH-alkaline phosphatase conjugate reacts with a different antigenic site on the hTSH. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, the chemiluminescent substrate Lumi-Phos™ 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of human thyroid-stimulating hormone in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve.

Human TSH is one of several glycoprotein hormones consisting of two non-covalently bound peptide chains: an a-chain, which is nearly identical in all, and a ß-chain, which is responsible for immunological and biological specificity. These similarities result in varying degrees of cross-reactivity of different antisera. The Access HYPERsensitive hTSH assay has virtually no cross-reactivity with other peptide hormones. The sensitivity and specificity of this test enable better discrimination between hyperthyroid and euthyroid patients.

Total T3 assay

The Access Total T3 assay is a competitive binding immunoenzymatic assay. Sample is added to a reaction vessel with a stripping agent to dissociate T3 from the binding proteins. T3 in the sample competes with the T3 analogue coupled to biotin for anti-T3 alkaline phosphatase conjugate. Of the resulting antigen/antibody complexes, the T3 analogue/antibody complexes are bound to the streptavidin coated solid phase. Separation in a magnetic field and washing removes the sample T3/antibody complexes and other materials not bound to the solid phase. Then, the chemiluminescent substrate Lumi-Phos™ 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of total T3 in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve.

Free T3 assay

Access Free T3 assay is a competitive binding immunoenzymatic assay. A sample is added to a reaction vessel with an anti-T3 monoclonal antibody conjugated to alkaline phosphatase. During the incubation, free T3 in the sample reacts with the anti-T3 antibody. Particles coated with streptavidin and biotinylated T3 analog are then added to the mixture. Unoccupied binding sites on the anti-T3 antibody are bridged to the particle through the T3 analog. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, the chemiluminescent substrate Lumi-Phos™ 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of free T3 in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve.

Total T4 assay

The Access Total T4 assay is a competitive binding immunoenzymatic assay. A sample is added to a reaction vessel with anti-thyroxine antibody, thyroxine-alkaline phosphatase conjugate, and paramagnetic particles coated with goat anti-mouse capture antibody and a stripping agent to dissociate all T4 from binding proteins. Thyroxine in the sample competes with the thyroxine-alkaline phosphatase conjugate for binding sites on a limited amount of specific anti-thyroxine antibody. Resulting antigen: antibody complexes bind to the capture antibody on the solid phase. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, the chemiluminescent substrate Lumi-Phos™ 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of thyroxine in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve.

Free T4 assay

The Access Free T4 (FRT4) assay is a two-step enzyme immunoassay. Monoclonal anti-Thyroxine (T4) antibody coupled to biotin, sample, buffered protein solution, and streptavidin-coated solid phase are added to the reaction vessel. During this first incubation, the anti-T4 antibody coupled to biotin binds to the solid phase and the free T4 in the sample. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Next, buffered protein solution and triiodothyronine (T3)-alkaline phosphatase conjugate are added to the reaction vessel. The T3-alkaline phosphatase conjugate binds to the vacant anti-T4 antibody binding sites. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, the chemiluminescent substrate Lumi-Phos™ 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of free T4 in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve.

Thyroglobulin (Tg) assay

The Access thyroglobulin (Tg) assay is a simultaneous one-step "sandwich" assay. A sample is added to a reaction vessel, along with biotinylated mixture of four monoclonal anti-Tg antibodies, streptavidin coated paramagnetic particles, and monoclonal anti-Tg antibody alkaline phosphatase conjugate. The biotinylated antibodies and the serum or plasma thyroglobulin bind to the solid phase, while the conjugate antibody reacts with a different antigenic site on the thyroglobulin molecule. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. A chemiluminescent substrate, Lumi-Phos** 530 is added to the reaction vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of thyroglobulin in the sample. The amount of Thyroglobulin in the sample is determined by means of a stored, multi-point calibration curve.

Thyroglobulin antibody assay (TgAb)

The Access thyroglobulin antibody assay is a sequential two-step immunoenzymatic "sandwich" assay. A sample is added to a reaction vessel with paramagnetic particles coated with the thyroglobulin protein. After incubation, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. The thyroglobulin-alkaline phosphatase conjugate is added and binds to the TgAb. After a second incubation, the reaction vessel is washed to remove unbound materials. A chemiluminescent substrate, Lumi-Phos™ 530 is added to the reaction vessel and light generated by the reaction is measured with a luminometer. The light production is proportional to the concentration of Thyroglobulin antibody in the sample. The amount of Thyroglobulin antibody in the sample is determined by means of a stored, multi-point calibration curve.

Thyroid peroxidase antibody

The Access TPO antibody (TPOAb) assay is a sequential two-step immunoenzymatic "sandwich" assay. A sample is added to a reaction vessel with paramagnetic particles coated with the thyroid peroxidase protein. After an incubation, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. The protein A-alkaline phosphatase conjugate is added and binds to the TPOAb. After a second incubation, the reaction vessel is washed to remove unbound materials. A chemiluminescent substrate, Lumi-Phos™ 530 is added to the reaction vessel and light generated by the reaction is measured with a luminometer. The light production is proportional to the concentration of TPO antibody in the sample. The amount of TPOAb in the sample is determined by means of a stored, multi-point calibration curve.

Data Processing and Editing

Read the General Documentation on Laboratory Data file for detailed data processing and editing protocols. The analytical methods are described in the Description of the Laboratory Methodology section.

Five variables in this data file were created. The formula for their creation is as follows:

Free thyroxine results (LBXT4F) in ng/dL were multiplied by 12.9 into pmol/L (LBDT4FSI).

Thyroglobin results LBXTGN) in ng/mL were multiplied by 1.0 into µg/L (LBDTGNSI).

Thyroid stimulating hormone results (LBXTSH1) in µIU/mL were multiplied by 1.0 into mIU/L (LBDTSH1S).

Total triiodothyronine results (LBXTT3) in ng/dL were multiplied by .0154 into nmol/L (LBDTT3SI).

Total triiodothyronine results (LBXTT3) in ng/dL were multiplied by .0154 into nmol/L (LBDTT3SI).

The variable named LBD___LC indicates whether the result was below the limit of detection. There are two values: “0” and “1””. “0” means that the result was at or above the limit of detection. “1” indicates that the result was below the limit of detection

Laboratory Quality Assurance and Monitoring

The NHANES quality control and quality assurance protocols (QA/QC) meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed quality control and quality assurance instructions are discussed in the NHANES LPM. Read the General Documentation on Laboratory Data file for detailed QA/QC protocols.

A detailed description of the quality assurance and quality control procedures can be found on the NHANES website.

Analytic Notes

The analysis of NHANES 2001–2002 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 2001–2002 Household Questionnaire Data Files contain demographic data, health indicators, and other related information collected during household interviews. They also contain all survey design variables and sample weights for these age groups. The phlebotomy file includes auxiliary information such as the conditions precluding venipuncture. The household questionnaire and phlebotomy files may be linked to the laboratory data file using the unique survey participant identifier SEQN.

Exam sample weights should be used for analyses. Please refer to the Analytic Guidelines for further details on the use of sample weights and other analytic issues. The Analytic Guidelines are available on the NHANES website.

References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 12 YEARS - 150 YEARS

LBXATG - Thyroglobulin antibodies (IU/mL)

Variable Name:
LBXATG
SAS Label:
Thyroglobulin antibodies (IU/mL)
English Text:
Thyroglobulin antibodies (IU/mL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.6 to 2391.9 Range of Values 6250 6250
. Missing 667 6917

LBXT3F - Triiodothyronine (T3), free (pg/mL)

Variable Name:
LBXT3F
SAS Label:
Triiodothyronine (T3), free (pg/mL)
English Text:
Triiodothyronine (T3), free (pg/mL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.8 to 20.7 Range of Values 6262 6262
. Missing 655 6917

LBXT4F - Thyroxine, free (ng/dL)

Variable Name:
LBXT4F
SAS Label:
Thyroxine, free (ng/dL)
English Text:
Thyroxine, free (ng/dL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.1 to 4.8 Range of Values 6264 6264
. Missing 653 6917

LBDT4FSI - Thyroxine, free (pmol/L)

Variable Name:
LBDT4FSI
SAS Label:
Thyroxine, free (pmol/L)
English Text:
Thyroxine, free (pmol/L)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.3 to 61.9 Range of Values 6264 6264
. Missing 653 6917

LBXTGN - Thyroglobulin (ng/mL)

Variable Name:
LBXTGN
SAS Label:
Thyroglobulin (ng/mL)
English Text:
Thyroglobulin (ng/mL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.07 to 4461 Range of Values 6262 6262
. Missing 655 6917

LBDTGNSI - Thyroglobulin (ug/L)

Variable Name:
LBDTGNSI
SAS Label:
Thyroglobulin (ug/L)
English Text:
Thyroglobulin (ug/L)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.07 to 4461 Range of Values 6262 6262
. Missing 655 6917

LBXTSH1 - Thyroid stimulating hormone (uIU/mL)

Variable Name:
LBXTSH1
SAS Label:
Thyroid stimulating hormone (uIU/mL)
English Text:
Thyroid stimulating hormone (uIU/mL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.002 to 280.76 Range of Values 6265 6265
. Missing 652 6917

LBDTSH1S - Thyroid stimulating hormone (mIU/L)

Variable Name:
LBDTSH1S
SAS Label:
Thyroid stimulating hormone (mIU/L)
English Text:
Thyroid stimulating hormone (mIU/L)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.002 to 280.76 Range of Values 6265 6265
. Missing 652 6917

LBXTPO - Thyroid peroxidase antibodies (IU/mL)

Variable Name:
LBXTPO
SAS Label:
Thyroid peroxidase antibodies (IU/mL)
English Text:
Thyroid peroxidase antibodies (IU/mL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.1 to 2376 Range of Values 6214 6214
. Missing 703 6917

LBXTT3 - Triiodothyronine (T3), total (ng/dL)

Variable Name:
LBXTT3
SAS Label:
Triiodothyronine (T3), total (ng/dL)
English Text:
Triiodothyronine (T3), total (ng/dL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
37 to 707 Range of Values 6262 6262
. Missing 655 6917

LBDTT3SI - Triiodothyronine (T3), total (nmol/L)

Variable Name:
LBDTT3SI
SAS Label:
Triiodothyronine (T3), total (nmol/L)
English Text:
Triiodothyronine (T3), total (nmol/L)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 to 11 Range of Values 6262 6262
. Missing 655 6917

LBXTT4 - Thyroxine, total (T4) (ug/dL)

Variable Name:
LBXTT4
SAS Label:
Thyroxine, total (T4) (ug/dL)
English Text:
Thyroxine, total (T4) (ug/dL)
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.5 to 27.6 Range of Values 6263 6263
. Missing 654 6917