Demographic, smoking, and nutritional determinants of 1,3-butadiene metabolites
Base model | Including covariates from stepwise regression | |||||
---|---|---|---|---|---|---|
Independent variables | Cumulative R2 | Regression coefficient | P | Cumulative R2 | Regression coefficient | P |
MHBMA, ng/mg Cr | ||||||
Age, y | 0.00004 | 1.00 | 0.005 | 0.16 | ||
Japanese American vs. whites | −0.429 | <0.0001 | −0.106 | 0.22 | ||
Native Hawaiian vs. whites | −0.238 | 0.02 | −0.212 | 0.01 | ||
Nicotine equivalents, nmol/mL | 0.188 | 0.002 | 0.187 | 0.0002 | ||
BMI, kg/m2 | −0.050 | 0.81 | 0.128 | 0.45 | ||
Sex | 5.30% | 0.038 | 0.65 | 0.116 | 0.10 | |
+GSTT1 (1/0) vs.(1/1)a | −0.495 | <0.0001 | ||||
(0/0) vs. (1/1) | 37.1% | −1.563 | <0.0001 | |||
DHBMA, ng/mg Cr | ||||||
Age, y | 0.005 | 0.08 | 0.007 | 0.02 | ||
Japanese American vs. whites | −0.087 | 0.19 | −0.020 | 0.77 | ||
Native Hawaiian vs. whites | −0.124 | 0.07 | −0.072 | 0.29 | ||
Nicotine equivalents, nmol/mL | 0.001 | 0.97 | 0.238 | 0.54 | ||
BMI, kg/m2 | −0.057 | 0.67 | 0.025 | 0.85 | ||
Sex | 2.50% | 0.121 | 0.03 | 0.181 | 0.001 | |
+Alcohol (g/1,000 kcal/d)a | 5.80% | 0.010 | <0.0001 | |||
MHBMA/(MHBMA + DHBMA) | ||||||
Age, y | −0.005 | 0.29 | −0.002 | 0.68 | ||
Japanese American vs. whites | −0.338 | 0.001 | −0.097 | 0.29 | ||
Native Hawaiian vs. whites | −0.117 | 0.27 | −0.154 | 0.09 | ||
Nicotine equivalents, nmol/mL | 0.186 | 0.003 | 0.151 | 0.004 | ||
BMI, kg/m2 | 0.012 | 0.96 | 0.076 | 0.67 | ||
Sex | 4.90% | −0.078 | 0.36 | −0.088 | 0.24 | |
+GSTT1 (1/0) vs. (1/1)a | −0.458 | <0.0001 | ||||
(0/0) vs. (1/1) | 30.5% | −1.427 | <0.0001 | |||
+Alcohol (g/1,000 kcal/d)a | 32.6% | −0.005 | <0.0001 |
NOTE: Variables allowed to compete in the stepwise regression: GSTT1 copy number polymorphism, CYP2A6 activity, smoking duration (years), and intakes of cruciferous vegetable, total fruits, caffeine, green leafy vegetables, total vegetables, alcohol, processed meats, and soy.
↵aAdditional predictor identified through stepwise regression.