Table 3.
Adjusted mean differences (β) in principal component scores for women based on socioeconomic, demographic, behavioral, dietary, and reproductive correlates for women included in this analysis from SELF (N= 749).a
| Variable | PC-1 β (95% CI) | PC-2 β (95% CI) | PC-3 β (95% CI) | PC-4 β (95% CI) |
|---|---|---|---|---|
| Age at enrollment, 1-year increase | 0.47 (0.39, 0.54) | 0.11 (0.06, 0.16) | 0.08 (0.04, 0.12) | 0.05 (0.01, 0.09) |
| Marital status | ||||
| Never married | Ref | Ref | Ref | Ref |
| Currently married | −0.25 (−0.85, 0.35) | 0.27 (−0.10, 0.65) | 0.001 (−0.33, 0.33) | 0.08 (−0.20, 0.36) |
| Previously married | −0.03 (−0.74, 0.68) | 0.30 (−0.14, 0.75) | 0.15 (−0.24, 0.55) | −0.15 (−0.48, 0.18) |
| Education | ||||
| HS degree/GED | Ref | Ref | Ref | Ref |
| Some college/Associate’s/Technical school | −0.69 (−1.36, −0.02) | 0.43 (0.01, 0.85) | 0.11 (−0.26, 0.48) | 0.02 (−0.29, 0.34) |
| Bachelor’s/Master’s/PhD | −0.58 (−1.48, 0.31) | 0.90 (0.34, 1.47) | −0.19 (−0.69, 0.31) | −0.28 (−0.70, 0.14) |
| Income | ||||
| <$20,000/year | Ref | Ref | Ref | Ref |
| $20-50,000/year | 0.20 (−0.40, 0.80) | 0.31 (−0.07, 0.68) | −0.17 (−0.51, 0.16) | −0.21 (−0.49, 0.07) |
| >$50,000/year | 0.62 (−0.21, 1.45) | 0.15 (−0.37, 0.67) | −0.31 (−0.77, 0.16) | −0.28 (−0.67, 0.10) |
| Employment | ||||
| Not employed | Ref | Ref | Ref | Ref |
| Employed <30 hours/week | 0.24 (−0.51, 0.99) | −0.37 (−0.84, 0.10) | −0.30 (−0.72, 0.12) | 0.21 (−0.14, 0.56) |
| Employed ≥30 hours/week | −0.01 (−0.58, 0.57) | −0.10 (−0.46, 0.26) | −0.24 (−0.57, 0.08) | 0.02 (−0.25, 0.29) |
| US born | ||||
| No | Ref | Ref | Ref | Ref |
| Yes | −0.19 (−2.59, 2.22) | 0.09 (−1.42, 1.60) | 0.27 (−1.07, 1.61) | −0.01 (−1.13, 1.11) |
| Smoking | ||||
| Non-smoker | Ref | Ref | Ref | Ref |
| Former smoker | 0.46 (−0.44, 1.37) | −0.63 (−1.20, −0.07) | 1.10 (0.60, 1.60) | 0.15 (−0.27, 0.57) |
| Current smoker <10 cigarettes/day | 0.31 (−0.46, 1.08) | −0.22 (−0.71, 0.26) | 0.43 (−0.001, 0.86) | 0.48 (0.12, 0.84) |
| Current smoker ≥10 cigarettes/day | 1.37 (0.20, 2.55) | −0.79 (−1.53, −0.05) | −0.22 (−0.88, 0.43) | 0.83 (0.29, 1.38) |
| Alcohol use | ||||
| Non-drinker | Ref | Ref | Ref | Ref |
| Moderate consumption | 0.42 (−0.14, 0.98) | 0.04 (−0.31, 0.40) | −0.41 (−0.72, −0.09) | 0.05 (−0.21, 0.31) |
| Heavy consumption | 1.03 (0.32, 1.73) | −0.21 (−0.66, 0.23) | −0.38 (−0.77, 0.01) | −0.11 (−0.44, 0.21) |
| BMI (kg/m2), 1-unit increase | −0.14 (−0.17, −0.12) | −0.01 (−0.03, 0.01) | −0.04 (−0.05, −0.02) | −0.04 (−0.05, −0.02) |
| Daily servings of dairy (milk equivalents) | −0.09 (−0.42, 0.24) | 0.03 (−0.18, 0.24) | 0.14 (−0.04, 0.33) | −0.15 (−0.30, 0.004) |
| Meats, ounces/day | −0.09 (−0.22, 0.03) | −0.01 (−0.09, 0.07) | −0.03 (−0.10, 0.05) | 0.03 (−0.03, 0.09) |
| Poultry, ounces/day | 0.17 (−0.04, 0.38) | 0.03 (−0.10, 0.16) | 0.06 (−0.06, 0.18) | 0.01 (−0.09, 0.10) |
| Eggs, ounces/day | 0.06 (−0.45, 0.57) | 0.16 (−0.16, 0.48) | 0.13 (−0.16, 0.41) | 0.07 (−0.17, 0.31) |
| Fish high in omegas, ounces/day | −0.15 (−1.74, 1.43) | −0.50 (−1.50, 0.49) | 0.43 (−0.45, 1.32) | −0.05 (−0.79, 0.68) |
| Fish low in omegas, ounces/day | 0.24 (−0.32, 0.80) | 0.17 (−0.18, 0.52) | −0.08 (−0.39, 0.23) | 0.13 (−0.13, 0.39) |
| Daily servings of fruits | −0.004 (−0.14, 0.13) | −0.01 (−0.09, 0.08) | −0.11 (−0.19, −0.04) | −0.02 (−0.08, 0.05) |
| Daily servings of vegetables | 0.02 (−0.27, 0.32) | 0.10 (−0.08, 0.29) | −0.05 (−0.21, 0.12) | 0.09 (−0.04, 0.23) |
| Parity | ||||
| Nulliparous | Ref | Ref | Ref | Ref |
| 1 | −0.21 (−0.86, 0.45) | 0.06 (−0.35, 0.47) | 0.54 (0.18, 0.91) | 0.0003 (−0.30, 0.30) |
| 2 | 0.14 (−0.64, 0.93) | −0.37 (−0.86, 0.12) | 0.46 (0.02, 0.90) | −0.31 (−0.68, 0.05) |
| ≥3 | 0.42 (−0.46, 1.30) | −0.61 (−1.16, −0.05) | 0.83 (0.34, 1.32) | −0.36 (−0.77, 0.05) |
| Totals months spent breastfeeding, 1-month increase | −0.09 (−0.14, −0.05) | −0.03 (−0.06, 0.001) | 0.03 (0.002, 0.05) | 0.01 (−0.01, 0.03) |
| First child of mother | ||||
| No | Ref | Ref | Ref | Ref |
| Yes | −0.33 (−0.80, 0.15) | −0.03 (−0.33, 0.27) | 0.04 (−0.22, 0.30) | 0.06 (−0.16, 0.28) |
| Breastfed in infancy | ||||
| Never | Ref | Ref | Ref | Ref |
| <3 months | 0.28 (−0.40, 0.96) | −0.57 (−0.99, −0.14) | −0.20 (−0.58, 0.18) | 0.18 (−0.14, 0.50) |
| ≥3 months | 1.05 (0.37, 1.73) | 0.08 (−0.35, 0.51) | 0.34 (−0.04, 0.72) | 0.47 (0.15, 0.79) |
| Age at menarche (years) | −0.04 (−0.22, 0.14) | 0.07 (−0.04, 0.19) | 0.03 (−0.07, 0.13) | 0.05 (−0.04, 0.13) |
| Ever use oral contraceptives | ||||
| No | Ref | Ref | Ref | Ref |
| Yes | −0.35 (−0.88, 0.19) | −0.28 (−0.62, 0.06) | −0.01 (−0.31, 0.29) | −0.21 (−0.46, 0.04) |
| Ever use progestin-only injectable | ||||
| No | Ref | Ref | Ref | Ref |
| Yes | −0.09 (−0.60, 0.41) | 0.10 (−0.22, 0.42) | −0.14 (−0.43, 0.14) | 0.08 (−0.16, 0.32) |
| Hormonal contraceptive use at baseline | ||||
| No | Ref | Ref | Ref | Ref |
| Yes | 0.12 (−0.42, 0.67) | −0.09 (−0.43, 0.25) | −0.40 (−0.71, −0.10) | 0.24 (−0.02, 0.49) |
| Years since last birth | ||||
| Nulliparous | Ref | Ref | Ref | Ref |
| <2 years | −0.77 (−1.47, −0.08) | −0.33 (−0.77, 0.11) | 0.94 (0.55, 1.32) | −0.18 (−0.50, 0.14) |
| 2-4 years | −0.08 (−0.79, 0.62) | −0.37 (−0.82, 0.07) | 0.52 (0.13, 0.91) | −0.13 (−0.45, 0.20) |
| ≥5 years | −0.38 (−1.14, 0.37) | −0.14 (−0.61, 0.34) | 0.60 (0.18, 1.01) | 0.07 (−0.28, 0.41) |
a
Principal component scores were calculated by multiplying each chemical’s z-score with the principal component loading factor and summing across all analytes.
b
Mean differences were adjusted for all other correlates.
c
Associations with years since last birth were estimated from a separate model that did not include parity or totals months spent breastfeeding due to high collinearity.