Table 4.

DDE and PCB model variables and predicted values, LIBCSP, 1996-1997

ln DDE, n = 1,007, R2 = 0.328ln PCB,*n = 999, R2 = 0.302
βSEPPartial r2βSEPPartial r2
Intercept−1.010.16−0.610.094
Age at reference date (y)0.0360.0022<0.00010.2130.0210.0013<0.00010.220
Triglycerides (g/L)0.160.032<0.00010.0230.0810.018<0.00010.030
Cholesterol (g/L)0.0860.0630.1750.0020.140.035<0.00010.012
Race (White = referent)
    Black0.740.094<0.00010.0450.250.053<0.00010.012
Current BMI tertile (0, 1, 2)0.270.046<0.00010.0280.0530.0260.04270.005
BMI30-gain quintile (0, 1, 2, 3, 4)−0.130.027<0.00010.0003−0.0660.017<0.00010.015
Lactation history<0.00010.0180.3300.003
Never lactated (referent)
    1-56 wk lactation−0.150.0600.0150.0870.058
    >56 wk lactation−0.460.095<0.00010.0190.086
BMI30-gain × lactation interactionNA0.0210.006
    BMI30-gain × 1-56 wk lactation−0.0560.024
    BMI30-gain × >56 wk lactation−0.0750.040
  • NOTE: The BMI30 variable instead of current BMI tertiles was not significant for DDE, but BMI30 predicted almost identical results for PCBs. Lactation variables were categorical, and the P is for the group. Models predicting lipid-corrected values had similar results: DDE: R2 = 0.291 (P < 0.0001, except as noted), intercept = −1.94, βs = age 0.035, race 0.075, BMI30-gain −0.13, current BMI tertile 0.26, triglycerides 0.034 (P = 0.28), cholesterol −0.28, lactation <57 weeks −0.14, >56 weeks −0.46. PCB: R2 = 0.268, intercept = −1.54, βs = age 0.021, race 0.27, BMI30-gain −0.066, BMI 0.048 (P = 0.066), triglycerides −0.043 (P = 0.016), cholesterol −0.226, lactation (P = 0.26 for group) <57 weeks 0.096, >56 weeks 0.032, BMI30-gain × lactation (P = 0.016 for group) <57 weeks −0.058, >56 weeks −0.078.

  • * Fish intake (quartiles) was also significant in the ln PCB model for women with this information, n = 796, R2 = 0.297, intercept = −0.63, β = 0.045 (fish quartile values = 0, 1, 2, 3; partial r2 = 0.009). The other βs in this model were almost identical to those for 796 women without fish intake, with similar Ps (R2 = 0.288) and those in the model for 999 women.

  • Partial r2 based on type I SS from GLM.

  • NA, not applicable.