Table 1.

Geometric means (95% confidence limits) for 1,3-butadiene metabolites by race/ethnicity and sex

MHBMA, ng/mg CrDHBMA, ng/mg CrMHBMA/(MHBMA + DHBMA)
nGeometric meana (95% CI)Geometric meana (95% CI)Geometric meana (95% CI)
Allb584
 Japanese Americans1964.4 (3.8–5.1)d506.8 (461.9–556.0)0.009 (0.007–0.010)d
 Native Hawaiian1935.3 (4.6–6.2)d488.6 (444.6–536.9)0.011 (0.009–0.012)
 Whites1956.7 (5.8–7.8)553.0 (504.4–606.3)0.012 (0.010–0.014)
Pc0.00020.170.005
Men2845.3 (4.7–6.0)485.2 (449.8–523.5)e0.011 (0.010–0.012)
 Japanese Americans964.3 (3.5–5.3)d469.9 (412.7–535.0)0.009 (0.007–0.011)d
 Native Hawaiian935.2 (4.2–6.4)460.7 (402.2–527.7)0.011 (0.009–0.014)
 Whites956.6 (5.4–8.1)527.7 (462.6–601.9)0.012 (0.010–0.015)
Pc0.020.310.12
Females3005.5 (4.9–6.2)547.5 (508.5–589.4)e0.010 (0.009–0.011)
 Japanese Americans1004.5 (3.7–5.5)d546.5 (479.7–622.6)0.008 (0.007–0.010)d
 Native Hawaiian1005.4 (4.5–6.6)518.1 (456.0–588.6)0.010 (0.009–0.013)
 Whites1006.9 (5.6–8.4)579.5 (510.0–658.4)0.012 (0.010–0.014)
Pc0.010.480.04

Abbreviation: CI, confidence interval.

  • aMeans are adjusted for age at urine collection, BMI (natural log), and nicotine equivalents (natural log).

  • bAlso adjusted for sex.

  • cP value is comparing the difference across the three races/ethnicities.

  • dP value comparing the difference with whites is <0.05.

  • eP value comparing difference across sex was significant: P = 0.02.