TY - JOUR
T1 - Urinary 5-aminolevulinic acid (ALA) adjusted by creatinine
T2 - A surrogate for plasma ALA?
AU - Sithisarankul, Pornchai
AU - Schwartz, Brian S.
AU - Lee, Byung Kook
AU - Strickland, Paul T.
PY - 1998/10
Y1 - 1998/10
N2 - 5-Aminolevulinic acid (ALA) is the first intermediate substrate in the heme synthetic pathway and is the substrate of aminolevulinic acid dehydratase (ALAD, porphobilinogen synthase). Because lead effectively inhibits ALAD activity, resulting in accumulation of ALA in urine and blood, urinary ALA (ALAU) has been used as a biomarker for lead exposure or early biologic effect of lead. Intraindividual variation in urinary excretion of ALA requires the use of 24-hour urine samples on adjustment of single urine samples by other normalizing variables, such as urinary creatinine concentration. Previous studies of ALAU concentration have used various adjustment methods; however, few have compared creatinine-adjusted ALAU concentration with ALA concentration in plasma (ALAP) from subjects with low (< 30 μg/dL) to moderate (< 60 μg/dL) levels of blood lead. To determine if creatinine-adjusted ALAU is associated with ALAP, we measured ALAU, ALAP, and urinary creatinine in 65 Korean lead workers with blood lead concentrations in the range of 14-60 μg/dL ALAU, ALAU/creatinine, or ALAU/log creatinine all correlated with ALAP. However, ALAU/creatinine correlated more closely with ALAP based on Spearman's r (r(s) = 0.40, P = 0.0009), supporting the use of ALA/creatinine in single urine samples as a surrogate for ALAP.
AB - 5-Aminolevulinic acid (ALA) is the first intermediate substrate in the heme synthetic pathway and is the substrate of aminolevulinic acid dehydratase (ALAD, porphobilinogen synthase). Because lead effectively inhibits ALAD activity, resulting in accumulation of ALA in urine and blood, urinary ALA (ALAU) has been used as a biomarker for lead exposure or early biologic effect of lead. Intraindividual variation in urinary excretion of ALA requires the use of 24-hour urine samples on adjustment of single urine samples by other normalizing variables, such as urinary creatinine concentration. Previous studies of ALAU concentration have used various adjustment methods; however, few have compared creatinine-adjusted ALAU concentration with ALA concentration in plasma (ALAP) from subjects with low (< 30 μg/dL) to moderate (< 60 μg/dL) levels of blood lead. To determine if creatinine-adjusted ALAU is associated with ALAP, we measured ALAU, ALAP, and urinary creatinine in 65 Korean lead workers with blood lead concentrations in the range of 14-60 μg/dL ALAU, ALAU/creatinine, or ALAU/log creatinine all correlated with ALAP. However, ALAU/creatinine correlated more closely with ALAP based on Spearman's r (r(s) = 0.40, P = 0.0009), supporting the use of ALA/creatinine in single urine samples as a surrogate for ALAP.
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U2 - 10.1097/00043764-199810000-00011
DO - 10.1097/00043764-199810000-00011
M3 - Article
C2 - 9800176
AN - SCOPUS:0031725894
SN - 1076-2752
VL - 40
SP - 901
EP - 906
JO - Journal of occupational and environmental medicine
JF - Journal of occupational and environmental medicine
IS - 10
ER -