Results of regression models for log urine cadmium/creatinine adjusted for age, race/ethnicity, sex, education, job category, body mass index, years ago quit smoking (for former smokers), pack years of cigarettes, cotinine level, and daily intake of dairy products, fruits, vegetables, meats and grains
| Variable | Current smokers | Former smokers | Never smokers |
|---|---|---|---|
| Data are presented as regression coefficients with 95% confidence intervals. | |||
| *Some never and former smokers had cotinine levels >15 ng/ml, suggesting misclassification of smoking status. | |||
| From the Third National Health and Nutrition Examination Survey, 1988–94. | |||
| Intercept | −3.68 (−4.30 to −3.06) | −2.62 (−2.96 to −2.28) | −2.90 (−3.12 to −2.68) |
| Age (10 years) | 0.38 (0.36 to 0.40) | 0.32 (0.30 to 0.34) | 0.31 (0.29 to 0.33) |
| Race/ethnicity | |||
| White | 0 | 0 | 0 |
| Black | 0.15 (0.07 to 0.23) | 0.12 (0.02 to 0.22) | 0.28 (0.14 to 0.42) |
| Mexican-American | 0.14 (0.00 to 0.28) | 0.13 (0.01 to 0.25) | 0.35 (0.23 to 0.47) |
| Other | 0.20 (0.00 to 0.40) | 0.17 (−0.01 to 0.35) | 0.32 (0.14 to 0.50) |
| Sex | |||
| Male | −0.33 (−0.41 to −0.25) | −0.42 (−0.50 to −0.34) | −0.58 (−0.66 to −0.50) |
| Female | 0 | 0 | 0 |
| Education level (years) | |||
| <12 | 0.17 (0.05 to 0.29) | 0.03 (−0.09 to 0.15) | −0.01 (−0.11 to 0.09) |
| 12 | 0.17 (0.07 to 0.27) | 0.06 (−0.04 to 0.16) | −0.02 (−0.14 to 0.10) |
| ⩾13 | 0 | 0 | 0 |
| Job category | |||
| Agriculture | 0.03 (−0.17 to 0.23) | −0.06 (−0.22 to 0.10) | −0.01 (−0.19 to 0.17) |
| Mining/manufacturing | 0.21 (0.05 to 0.37) | 0.15 (0.03 to 0.27) | 0.10 (−0.04 to 0.24) |
| Transport | 0.27 (0.07 to 0.47) | 0.17 (0.05 to 0.29) | 0.12 (−0.10 to 0.34) |
| Service | 0.09 (−0.05 to 0.23) | 0.03 (−0.11 to 0.17) | 0.03 (−0.09 to 0.15) |
| Unemployed | 0.17 (−0.03 to 0.37) | 0.06 (−0.14 to 0.26) | 0.02 (−0.12 to 0.16) |
| Retail | 0 | 0 | 0 |
| Body mass index (kg/m2) | |||
| <18.5 | 0.03 (−0.19 to 0.25) | −0.25 (−0.75 to 0.25) | 0.08 (−0.24 to 0.40) |
| 18.5–24 | 0 | 0 | 0 |
| 25–29 | 0.08 (0.00 to 0.16) | 0.03 (−0.07 to 0.13) | 0.09 (0.01 to 0.17) |
| ⩾30 | −0.05 (−0.13 to 0.03) | 0.05 (−0.07 to 0.17) | 0.04 (−0.06 to 0.14) |
| Years ago quit smoking cigarettes | |||
| >0–10 | 0.54 (0.36 to 0.72) | ||
| >10–20 | 0.29 (0.11 to 0.47) | ||
| >20–30 | 0.20 (0.00 to 0.40) | ||
| >30–40 | 0.11 (−0.11 to 0.33) | ||
| >40 | 0 | ||
| Unknown | 0.53 (0.31 to 0.75) | ||
| Pack years of cigarettes | |||
| ⩾60 | 0.59 (0.27 to 0.91) | 0.24 (0.00 to 0.48) | |
| ⩽30–59 | 0.61 (0.37 to 0.85) | 0.14 (−0.08 to 0.36) | |
| >0–29 | 0.43 (0.21 to 0.65) | −0.26 (−0.50 to −0.02) | |
| 0 | 0 | 0 | |
| Cotinine level (ng/ml)* | |||
| >100 | 0.93 (0.33 to 1.53) | 0.23 (0.03 to 0.43) | 0.34 (0.14 to 0.54) |
| ⩽15–100 | 0.31 (−0.31 to 0.93) | 0.04 (−0.28 to 0.36) | 0.15 (−0.13 to 0.43) |
| ⩽0.3–15 | 0.20 (−0.44 to 0.84) | 0.16 (0.02 to 0.30) | 0.26 (0.14 to 0.38) |
| 0.05–0.29 | 0.08 (−0.62 to 0.78) | 0.15 (0.01 to 0.29) | 0.18 (0.04 to 0.32) |
| Non-detectable | 0 | 0 | 0 |
| Missing | 0.82 (0.22 to 1.42) | 0.08 (−0.18 to 0.34) | 0.09 (−0.11 to 0.29) |
| Dietary factors | |||
| Dairy intake | 0.00 (−0.04 to 0.04) | −0.06 (−0.10 to −0.02) | 0.00 (−0.04 to 0.04) |
| Fruit intake | −0.01 (−0.03 to 0.01) | −0.01 (−0.03 to 0.01) | −0.01 (−0.03 to 0.01) |
| Vegetable intake | 0.08 (0.06 to 0.10) | 0.01 (−0.03 to 0.05) | 0.02 (0.00 to 0.04) |
| Meat intake | −0.05 (−0.11 to 0.01) | −0.02 (−0.08 to 0.04) | 0.05 (0.01 to 0.09) |
| Grain intake | −0.02 (−0.06 to 0.02) | −0.02 (−0.06 to 0.02) | −0.05 (−0.07 to −0.03) |
| r2 of model | 0.41 | 0.39 | 0.30 |