Table 2.

Influence of selected factors on urinary PGE-M level (ng/mg Cr) among controls by menopausal status

Postmenopausal controls (n = 603)Premenopausal controls (n = 479)
VariablesNo.Geometric mean (SD)PaNo.Geometric mean (SD)Pa
Age at sample collection, yb
 ≤4546.46 (1.621)1888.31 (1.61)
 46–50139.31 (1.45)1988.71 (1.54)
 51–557710.38 (1.47)889.69 (1.60)
 56–6012211.20 (1.65)<0.00158.73 (1.34)0.081
 61–6516911.25 (1.64)
 >6521813.14 (1.60)
Educationc
 <High school21510.72 (1.62)1988.40 (1.55)
 ≥High school38812.26 (1.61)0.0482818.95 (1.60)0.121
BMI, kg/m2d
 <2533311.34 (1.56)3398.35 (1.53)
 25–29.921511.85 (1.64)0.0201249.37 (1.69)0.001
 ≥305514.03 (1.84)1612.63 (1.76)
Cigarette smoking statusd
 Nonsmokers58011.59 (1.60)4698.68 (1.58)
 Ever-smokers2314.41 (1.89)0.1111010.63 (1.77)0.193
Regular physical activityd
 No31611.26 (1.58)3548.76 (1.58)
 Yes28712.15 (1.64)0.1131258.58 (1.58)0.638
Family history of breast cancerd
 No59211.65 (1.61)4738.90 (1.58)
 Yes1113.79 (1.79)0.19668.28 (1.96)0.756
Age at menarche, yd
 ≤123310.82 (1.90)287.85 (1.44)
 13–1532311.47 (1.59)0.9042988.48 (1.57)0.086
 >1524712.09 (1.61)1529.37 (1.62)
Age at first live birth, yd
 <2537712.22 (1.62)899.39 (1.51)
 26–3016610.83 (1.60)0.3842948.60 (1.62)0.469
 >304510.71 (1.70)848.32 (1.55)
Number of live birthsd
 01511.39 (1.35)129.60 (1.43)
 19310.17 (1.62)0.5614058.47 (1.59)0.049
 ≥249512.0 (1.62)6210.36 (1.47)
Breastfeeding, moe
 ≤Median29010.80 (1.60)2538.67 (1.60)
 >Median29812.60 (1.63)0.0952148.73 (1.57)0.633
  • aP values derived from ANOVA.

  • bAge at sample collection was not adjusted.

  • cEducation was adjusted for age at sample collection.

  • dBMI, cigarette smoking status, regular physical activity, family history of breast cancer, age at menarche, age at first live birth, number of live births, and breastfeeding were adjusted for age at sample collection and education.

  • eBreastfeeding: among postmenopausal women, median = 23 months; among premenopausal women, median = 8 months.