Table of Contents

Component Description

β-trace protein (BTP) & β2 microglobulin (B2M) assayed from stored surplus serum samples from NHANES III (1988-1994)

Eligible Sample

BTP and B2M were measured in 2009 at the University of Minnesota in stored surplus serum samples from NHANES III participants with valid cystatin C and serum creatinine measurements

Description of Laboratory Methodology

β-trace protein was assayed using the N Latex β-trace protein assay, Siemens Diagnostics, IL. β2 microglobulin was assayed using the N Latex β2 microglobulin assay, Siemens Diagnostics, IL.

Data Processing and Editing

All data have been made publicly available.

Laboratory Quality Assurance and Monitoring

The assay range is 0.23 - 7.25 mg/dL. The inter-assay coefficients of variation for the βTP and β2M assays were 5.7% (mean 0.594 mg/L) and 2.7% (mean 1.757 mg/L).

Analytic Notes

The sub-sample of participants with BTP and B2M measurements required modification of original sampling weights. These weights are the same as those provided for the prior NHANES III Cystatin C subsample and have been adjusted by age, sex, race, and serum creatinine strata to match the original NHANES III design.

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 - 90 YEARS

SSB2M - Beta-2 microglobulin (mg/L)

Variable Name:
SSB2M
SAS Label:
Beta-2 microglobulin (mg/L)
English Text:
Beta-2 microglobulin (mg/L)
Target:
Both males and females 12 YEARS - 90 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.253 to 61.7 Range of Values 7705 7705
. Missing 102 7807

SSBTP - Beta-trace protein (mg/L)

Variable Name:
SSBTP
SAS Label:
Beta-trace protein (mg/L)
English Text:
Beta-trace protein (mg/L)
Target:
Both males and females 12 YEARS - 90 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.156 to 21.3 Range of Values 7700 7700
. Missing 107 7807

WTCYPEX6 - Serum Cystatin MEC sample weight

Variable Name:
WTCYPEX6
SAS Label:
Serum Cystatin MEC sample weight
English Text:
Serum Cystatin MEC sample weight
Target:
Both males and females 12 YEARS - 90 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 557278.42094 Range of Values 7647 7647
. Missing 160 7807

WTCYPHX6 - Serum Cystatin MEC+Home sample weight

Variable Name:
WTCYPHX6
SAS Label:
Serum Cystatin MEC+Home sample weight
English Text:
Serum Cystatin MEC+Home sample weight
Target:
Both males and females 12 YEARS - 90 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 555987.69015 Range of Values 7721 7721
. Missing 86 7807

WTSCREX6 - Serum Creatinine MEC sample weight

Variable Name:
WTSCREX6
SAS Label:
Serum Creatinine MEC sample weight
English Text:
Serum Creatinine MEC sample weight
Target:
Both males and females 12 YEARS - 90 YEARS
Code or Value Value Description Count Cumulative Skip to Item
231.90933542 to 149994.33431 Range of Values 7647 7647
. Missing 160 7807

WTSCRHX6 - Serum Creatine MEC+Home sample weight

Variable Name:
WTSCRHX6
SAS Label:
Serum Creatine MEC+Home sample weight
English Text:
Serum Creatine MEC+Home sample weight
Target:
Both males and females 12 YEARS - 90 YEARS
Code or Value Value Description Count Cumulative Skip to Item
230.64285023 to 149245.02088 Range of Values 7721 7721
. Missing 86 7807