• Component Description
• Eligible Sample
• Description of Laboratory Methodology
• Data Processing and Editing
• Laboratory Quality Assurance and Monitoring
• Analytic Notes
• References
• Codebook
  • SEQN - Respondent sequence number
  • LBXEPP - Protoporphyrin(ug/dL RBC)
  • LBDEPPSI - Protoporphyrin (umol/L RBC)

National Health and Nutrition Examination Survey

2005-2006 Data Documentation, Codebook, and Frequencies

Erythrocyte Protoporphyrin (EPP_D)

Data File: EPP_D.xpt

First Published: December 2007

Last Revised: NA

Component Description

Protoporphyrin

The objectives of this component are:

1. to provide data for monitoring secular trends in measures of nutritional status in the U.S. population;
2. to evaluate the effect of people's habits and behaviors such as physical activity and the use of alcohol, tobacco, and dietary supplements on people's nutritional status; and
3. to evaluate the effect of changes in nutrition and public health policies including welfare reform legislation, food fortification policy, and child nutrition programs on the nutritional status of the U.S. population.

These data will be used to estimate deficiencies and toxicities of specific nutrients in the population and subgroups, to provide population reference data, and to estimate the contribution of diet, supplements, and other factors to serum levels of nutrients. Data will be used for research to further define nutrient requirements as well as optimal levels for disease prevention and health promotion.

Eligible Sample

Participants aged 3-5 years and females 12-49 years were tested.

Description of Laboratory Methodology

Porphyrins and heme components are extracted from whole blood into a 4:1 mixture of ethyl acetate-acetic acid. Porphyrins are then separated from heme by back-extraction into a 1.5 M hydrochloric acid solution, and quantitatively determined by molecular fluorometry using a spectrofluorometer calibrated with protoporphyrin IX (PPIX) standard solutions; however, the exact concentration of the standards must first be established using molecular absorbance, Beer’s Law, and the millimolar absorptivity of PPIX.

The analytical method for EP routinely employed by the EP Lab is based largely on those originally described by Sassa et al. (1973) and Chisolm and Brown (1975). New York State’s extraction method owes much to contributions from other public health labs, including the CDC, and closely follows the key elements of the consensus method for EP as published by the National Committee for Clinical Laboratory Standards (NCCLS C42-A*, 2001). At the invitation of Dr. Sassa, the EP Laboratory’s routine method for EP was published as Unit 8.8 in Current Protocols in Toxicology, 1999 by J. Wiley & Sons, Inc. Elements of this protocol are reproduced below, but a reprint of the original publication is available from the EP lab director. 

There were no changes in the laboratory method or lab site from the previous two years for erythrocyte protoporphyrin.

Data Processing and Editing

Specimens were processed, stored and shipped to the State of New York Department of Health, Wadsworth Center, Trace Metals Laboratory, Albany, New York. Detailed specimen collection and processing instructions was discussed in the NHANES LPM. Read the LABDOC file for detailed data processing and editing protocols. The analytical methods were described in the Description of the Laboratory Methodology section.

One derived variable was created in this data file. The formula for their derivation is as follows:
LBDEPPSI:

The protoporphyrin in μg/dL RBC (LBXEPP) was converted to μmol/L (LBDEPPSI) by multiplying by 0.0177.

Laboratory Quality Assurance and Monitoring

The NHANES quality control and quality assurance protocols (QA/QC) meet the 1988 Clinical Laboratory Improvement Amendments mandates. A detailed quality control and quality assurance instruction was discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM). Read the LABDOC file for detailed QA/QC protocols.

Analytic Notes

The analysis of NHANES 2005-2006 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 2005-2006 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.

References

• Blumberg, W.E., Eisinger, J., Lamola, A.A., and Zuckerman, D.M. 1977b. Zinc protoporphyrin level in blood determined by a portable hematofluorometer: a screening device for lead poisoning. J Lab Clin Med. 89:712–723.
• Bowers, M.A., Aicher, L.D., Davis, H.A., and Woods, J.S. 1992. Quantitative determination of porphyrins in rat and human urine and evaluation of urinary porphyrin profiles during mercury and lead exposures. J Lab Clin Med. 120:272–281.
• Centers for Disease Control, 1975. Increased lead absorption and lead poisoning in young children [Report]. U.S. Department of Health, Education, and Welfare, Atlanta, GA.
• Centers for Disease Control, 1978. Preventing lead poisoning in young children [Report]. U.S. Department of Health, Education, and Welfare, Atlanta, GA.
• Centers for Disease Control, 1985. Preventing lead poisoning in young children [Report]. U.S. Department of Health and Human Services, Atlanta, GA.
• Centers for Disease Control, 1991. Preventing lead poisoning in young children [Report]. U.S. Department of Health and Human Services, Atlanta, GA.
• Chiba, M. and Sassa, S. 1982. Analysis of porphyrin carboxylic acids in biological fluids by high- performance liquid chromatography. Anal Biochem. 124:279–285.
• Chisolm, J.,Jr. and Brown, D.H. 1975. Micro-scale photofluorometric determination of "free erythrocyte pophyrin" (protoporphyrin IX). Clin Chem. 21:1669–1682.
• Committee on Specifications and Criteria for Biochemical Compounds, National Research Council. Specifications and criteria for biochemical compounds, 3rd ed. Washington, D.C.: National Academy of Sciences, 1972.
• Culbreth P, Walter G, Carter R, Burtis C. Separation of protoporphyrin and related compounds by reversed-phase liquid chromatography. Clin Chem. 1979; 25(6):605–610.
• Doran, D. and Mitchell, D.G. 1984. Problems in the determination of erythrocyte protoporphyrin by ethyl acetate-acetic acid extraction. Ann Clin Biochem. 21:141–145.
• Gunter EW, Lewis BL, Koncikowski SM. Laboratory methods used for the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994. Centers for Disease Control and Prevention, Hyattsville, MD., 1996. VII-A-1 to VII-A-XII.
• Gunter EW, Miller DT. Laboratory procedures used by the Division of Environmental Health Laboratory Sciences, Center for Environmental Health, Centers for Disease Control, for the Hispanic Health and Nutrition Examination Survey (HHANES) 1982-84. Atlanta: Centers for Disease Control, 1986: 9–13.
• Gunter EW, Turner WE, Huff DL. Investigation of protoporphyrin IX standard materials used in acid-extraction methods, and a proposed correction for the millimolar absorptivity of protoporphyrin IX. Clin Chem. 1989;35(8):1601–1609.
• Gunter EW, Turner WE, Neese JW, Bayse DD. Laboratory procedures used by the Clinical Chemistry Division, Centers for Disease Control, for the Second Health and Nutrition Examination Survey (NHANES 1999+ II) 1976-80. Atlanta: Centers for Disease Control, 1981: 8-12.
• Gunter, E.W., Turner, W.E., and Huff, D.L. 1989. Investigation of protoporphyrin IX standard materials used in acid- extraction methods, and a proposed correction for the millimolar absorptivity of protoporphyrin IX. Clin Chem. 35:1601–1608.
• Ho, J., Guthrie, R., and Tieckelmann, H. 1987. Quantitative determination of porphyrins, their precursors and zinc protoporphyrin in whole blood and dried blood by high-performance liquid chromatography with fluorimetric detection. J Chromatogr. 417:269–276.
• Kammholz, L.P., Thatcher, L.G., Blodgett, F.M., and Good, T.A. 1972. Rapid protoporphyrin quantitation for detection of lead poisoning. Pediatrics. 50:625–631.
• National Committee for Clinical Laboratory Standards., 1996. Erythrocyte protoporphyrin testing; Approved guideline. 1 pp. NCCLS Document C42-A, Wayne, PA.
• Parsons, P.J., Reilly, A.A., and Hussain, A 1991. Observational Study of Erythrocyte Protoporphyrin as a Screening Test for Detecting Lead Exposure in Children: Impact of Lowering the Blood Lead Action Threshold Clin Chem. 37:216-225.
• Piomelli, S. 1973. A micromethod for free erythrocyte porphyrins: the FEP test. J Lab Clin Med. 81:932-940.
• Sagen, E. and Romslo, I. 1985. Determination of porphyrins by high performance liquid chromatography: fluorescence detection compared to absorbance detection. Scand. J Clin Lab Invest. 45:309-314.
• Sassa S, Granick JL, Granick S, Kappas A, Levere RD. Microanalyses of erythrocyte protoporphyrin levels by spectrophotometry in the detection of chronic lead intoxication in the subclinical range. Biochem Med. 1973;8:135–148.
• Sassa, S., Granick, J.L., Granick, S., Kappas, A., and Levere, R.D. 1973. Studies in lead poisoning. I. Microanalysis of erythrocyte protoporphyrin levels by spectrophotometry in the detection of chronic lead intoxication in the subclinical range. Biochem Med. 8:135-148.
• Sato, H., Ido, K., and Kimura, K. 1994. Simultaneous separation and quantification of free and metal-chelated protoporphyrins in blood by three-dimensional HPLC. Clin Chem. 40:1239-1244.
• Schwartz, S., Berg, M.H., Bossenmaier, I., and Dinsmore, H. 1960. Determination of porphyrins in biological materials. In Methods of biochemical analysis, Vol VIII, D. Glick ed.) pp. 221-294. Interscience Publishers, Inc., New York.
• Scoble, H.A., McKeag, M., Brown, P.R., and Kavarnos, G.J. 1981. The rapid determination of erythrocyte porphyrins using reversed-phase high performance liquid chromatography. Clin Chim Acta. 113:253-265.
• State of New York Department of Health, Wadsworth Center, Trace Metals Laboratory: Blumberg, W.E., Eisinger, J., Lamola, A.A., and Zuckerman, D.M. 1977a. The hematofluorometer. Clin Chem. 23:270–274.
• Washington, D.C.: U.S. Government Printing Office, 1982.

Codebook and Frequencies