• Component Description
• Eligible Sample
• Description of Laboratory Methodology
• Laboratory Method Files
• Laboratory Quality Assurance and Monitoring
• Data Processing and Editing
• Analytic Notes
• References
• Codebook
  • SEQN - Respondent sequence number
  • WTSA2YR - Subsample A Weights
  • URXAAC - A-a-C (pg/mL)
  • URDAACLC - A-a-C (pg/mL) Comment Code
  • URXGLP1 - Glu-P-1 (pg/mL)
  • URDGP1LC - Glu-P-1 (pg/mL) Comment Code
  • URXGLP2 - GLU-P-2 (pg/mL)
  • URDGP2LC - GLU-P-2 (pg/mL) Comment Code
  • URXHM - Harman (pg/mL)
  • URDHMLC - Harman (pg/mL) Comment Code
  • URXIQ - IQ (pg/mL)
  • URDIQLC - IQ (pg/mL) Comment Code
  • URXMAAC - MeA-a-C (pg/mL)
  • URDMACLC - MeA-a-C (pg/mL) Comment Code
  • URXNHM - Norharman (pg/mL)
  • URDNHMLC - Norharman (pg/mL) Comment Code
  • URXPHIP - PhlP (pg/mL)
  • URDPHPLC - PhlP (pg/mL) Comment Code
  • URXTRP1 - Trp-P-1 (pg/mL)
  • URDTP1LC - Trp-P-1 (pg/mL) Comment Code
  • URXTRP2 - Trp-P-2 (pg/mL)
  • URDTP2LC - Trp-P-2 (pg/mL) Comment Code

National Health and Nutrition Examination Survey

2013-2014 Data Documentation, Codebook, and Frequencies

Heterocyclic Aromatic Amines - Urine (HCAA_H)

Data File: HCAA_H.xpt

First Published: September 2017

Last Revised: NA

Component Description

Heterocyclic aromatic amines (HCAA) are an important class of carcinogens formed during combustion of cigarettes and cooking meats at high temperature (Turesky, R.J., Zhang, L., et al.). Studies have shown that HCAAs have a potential impact on human health, and in particular, on cancer risk due to frequent exposure. The International Agency for Research on Cancer (IARC) has considered a number of HCAAs as possible and probable carcinogens.

Eligible Sample

Examined participants aged 6 years and older from a one-third sample were eligible.

Description of Laboratory Methodology

Heterocyclic aromatic amines in urine are measured by an isotope-dilution high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (ID HPLC-ESI MS/MS). For "total" HCAA assays, the urine samples are fortified with internal standards (ISTD), and hydrolyzed in basic condition at 70°C for 5 hours. The samples are then extracted by solid phase extraction, after which the analytes are eluted and analyzed by LC/MS/MS. The analyte specific ion transitions are monitored for HCAA quantitation, confirmation and ISTD respectively. The concentrations are derived from their respective ratios of native to isotope-labeled ions in the samples by comparing to their standard curves.

Refer to the Laboratory Method Files section for a detailed description of the laboratory methods used.

This is a new component in the NHANES 2013-2014 cycle.

Laboratory Method Files

Heterocyclic Aromatic Amines (HCAA) (September 2017)

Laboratory Quality Assurance and Monitoring

Urine specimens were processed, stored, and shipped to Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA for analysis.

Detailed instructions on specimen collection and processing are discussed in the NHANES Laboratory Procedures Manual (LPM).

Vials are stored under appropriate frozen (–20°C) conditions until they are shipped to National Center for Environmental Health for testing.

The NHANES quality assurance and quality control (QA/QC) protocols meet the 1988 Clinical Laboratory Improvement Amendments mandates. Detailed QA/QC instructions are discussed in the NHANES LPM.

Mobile Examination Centers (MECs)

Laboratory team performance is monitored using several techniques. NCHS and contract consultants use a structured competency assessment evaluation during visits to evaluate both the quality of the laboratory work and the quality-control procedures. Each laboratory staff member is observed for equipment operation, specimen collection and preparation; testing procedures and constructive feedback are given to each staff member. Formal retraining sessions are conducted annually to ensure that required skill levels were maintained.

Analytical Laboratories

NHANES uses several methods to monitor the quality of the analyses performed by the contract laboratories. In the MEC, these methods include performing blind split samples collected on “dry run” sessions. In addition, contract laboratories randomly perform repeat testing on 2% of all specimens.

NCHS developed and distributed a quality control protocol for all CDC and contract laboratories which outlined the use of Westgard rules (Westgard et al., 1981) when running NHANES specimens. Progress reports containing any problems encountered during shipping or receipt of specimens, summary statistics for each control pool, QC graphs, instrument calibration, reagents, and any special considerations are submitted to NCHS quarterly. The reports are reviewed for trends or shifts in the data. The laboratories are required to explain any identified areas of concern.

All QC procedures recommended by the manufacturers were followed. Reported results for all assays meet the Tobacco and Volatile Branch, Division of Laboratory Services quality control and quality assurance performance criteria for accuracy and precision, similar to the Westgard rules (Caudill et al., 2008).

Data Processing and Editing

The data were reviewed. Incomplete data or improbable values were sent to the performing laboratory for confirmation.

Analytic Notes

Refer to the 2013-2014 Laboratory Data Overview for general information on NHANES laboratory data.

Subsample Weights

Heterocyclic aromatic amines were measured in a special smoking subsample of persons 18 years and older. Special sample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should be used when analyzing these data.

Demographic and Other Related Variables

The analysis of NHANES laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2013-2014 Demographics File contains demographic data, health indicators, and other related information collected during household interviews as well as the sample design variables. The recommended procedure for variance estimation requires use of stratum and PSU variables (SDMVSTRA and SDMVPSU, respectively) in the demographic data file.

This laboratory data file can be linked to the other NHANES data files using the unique survey participant identifier (i.e., SEQN).

Detection limits

The detection limits were constant for all of the analytes in the data set. Two variables are provided for each of these analytes. The variable name ending in “LC” (ex., URDAACLC) indicates whether the result was below the limit of detection: “0” means that the result was at or above the limit of detection, “1” indicates that the result was below the limit of detection. For analytes with analytic results below the lower limit of detection (ex., URDAACLC=1), an imputed fill value was placed in the analyte results field. This value is the lower limit of detection divided by square root of 2 (LLOD/sqrt [2]). The other variable prefixed URX (ex., URXAAC) provides the analytic result for that analyte.

Lower Limit of Detection (LLOD, in pg/mL) for Heterocyclic Aromatic Amines:

 

VARIABLE NAME	ANALYTE	LLOD
URXAAC	2-Amino-9H-pyrido[2,3-b]indole (A-a-C)	0.62
URXGLP1	2-Amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1)	0.31
URXGLP2	2-Aminodipyrido[1,2-a:3',2'-d] imidazole (GLU-P-2)	0.83
URXHM	Harman	4.59
URXIQ	2-Amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ)	0.37
URXMAAC	2-Amino-3-methyl-9H-pyriodo[2,3-b]indole (MeA-a-C)	0.33
URXNHM	Norharman	12.6
URXPHIP	2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)	0.34
URXTRP1	3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1)	0.79
URXTRP2	1-Methyl-3-amino-5H-pyrido[4,3-b]indole (Trp-P-2)	0.63

References

• Caudill, S.P., Schleicher, R.L., Pirkle, J.L. Multi-rule quality control for the age-related eye disease study. Statist. Med. (2008) 27(20):4094-40106.
• Turesky, R.J. (2002) Heterocyclic aromatic amine metabolism, DNA adduct formation, mutagenesis, and carcinogenesis. Drug Metab Rev. 34,625-650.
• Westgard J.O., Barry P.L., Hunt M.R., Groth T. A multi-rule Shewhart chart for quality control in clinical chemistry. Clin Chem (1981) 27:493-501.
  
• Zhang, L., Ashley, D.L., and Watson, C.H. (2011) Quantitative analysis of six heterocyclic aromatic amines in mainstream cigarette smoke condensate using isotope dilution liquid chromatography-electrospray ionization tandem mass spectrometry. Nicotine Tob Res. 13,120-126.

Codebook and Frequencies