Table 2.
Adjusted geometric means (pmol/mg creatinine) of urinary estrogen and estrogen metabolite levels by average frequency of aspirin use in 1997 and 1999: Nurses' Health Study II (n = 603)
| Aspirin | p for differencea | p for trend | |||
|---|---|---|---|---|---|
| Frequency of use (tablet/week) | |||||
| 0 | 1 | 2+ | |||
| N | 486 | 44 | 73 | ||
| Total estrogens and estrogen metabolites | 199 | 219 | 193 | 0.60 | 0.91 |
| Parent estrogens | 41 | 47 | 39 | 0.57 | 0.74 |
| Estrone | 28 | 30 | 26 | 0.56 | 0.80 |
| Estradiol | 14 | 15 | 13 | 0.51 | 0.70 |
| Catechols | 61 | 66 | 58 | 0.61 | 0.82 |
| 2-Catechols | 54 | 57 | 51 | 0.61 | 0.83 |
| 2-Hydroxyestrone | 48 | 50 | 45 | 0.63 | 0.86 |
| 2-Hydroxyestradiol | 5.3 | 6.2 | 5.1 | 0.73 | 0.95 |
| 4-Catechols | |||||
| 4-Hydroxyestrone | 5.6 | 6.1 | 5.1 | 0.45 | 0.70 |
| Methylated catechols | 10.4 | 10.2 | 8.6 | 0.04 | 0.13 |
| Methylated 2-catechols | 10.0 | 9.7 | 8.3 | 0.05 | 0.14 |
| 2-Methoxyestrone | 7.8 | 7.6 | 6.6 | 0.08 | 0.18 |
| 2-Methoxyestradiol | 0.72 | 0.69 | 0.60 | 0.06 | 0.10 |
| 2-Hydroxyestrone-3-methyl ether | 1.21 | 1.26 | 0.95 | 0.01 | 0.07 |
| Methylated 4-catechols | 0.21 | 0.25 | 0.21 | 0.84 | 0.66 |
| 4-Methoxyestrone | 0.13 | 0.16 | 0.14 | 0.93 | 0.20 |
| 4-Methoxyestradiol | 0.05 | 0.05 | 0.04 | 0.21 | 0.27 |
| 2-Hydroxylation pathway | 65 | 68 | 60 | 0.37 | 0.57 |
| 4-Hydroxylation pathway | 5.9 | 6.7 | 5.6 | 0.61 | 0.89 |
| 16-Hydroxylation pathway | 70 | 72 | 72 | 0.74 | 0.51 |
| 16α-Hydroxyestrone | 12 | 13 | 12 | 0.76 | 0.75 |
| Estriol | 30 | 31 | 32 | 0.55 | 0.47 |
| 17-Epiestriol | 1.62 | 1.44 | 1.67 | 0.81 | 0.77 |
| 16-Ketoestradiol | 15 | 15 | 13 | 0.20 | 0.11 |
| 16-Epiestriol | 6.3 | 7.3 | 6.6 | 0.54 | 0.41 |
| Ratios of metabolic pathways | |||||
| 4-Catechols/2-catechols | 0.10 | 0.10 | 0.10 | 0.88 | 0.87 |
| 2-Catechols/16-pathway | 0.76 | 0.77 | 0.73 | 0.74 | 0.76 |
| Catechols/16-pathway | 0.86 | 0.82 | 0.84 | 0.89 | 0.93 |
| 4-Pathway/2-pathway | 0.09 | 0.11 | 0.09 | 0.95 | 0.92 |
| 2-Pathway/16-pathway | 0.92 | 0.85 | 0.87 | 0.63 | 0.69 |
| 4-Pathway/16-pathway | 0.09 | 0.09 | 0.08 | 0.70 | 0.78 |
| 2,4-Pathway/16-pathway | 1.0 | 0.97 | 0.98 | 0.66 | 0.70 |
| 2-Pathway/4,16-pathway | 0.82 | 0.80 | 0.76 | 0.50 | 0.53 |
| 2-Catechols/methylated 2-catechols | 5.3 | 5.7 | 6.2 | 0.04 | 0.05 |
| 4-Catechols/methylated 4-catechols | 25 | 25 | 24 | 0.82 | 0.66 |
| Catechols/methylated catechols | 5.8 | 6.2 | 6.7 | 0.04 | 0.05 |
| Parent estrogens/estrogen metabolites | 1.5 | 1.3 | 1.5 | 0.82 | 0.94 |
| 2-Pathway/parent estrogens | 0.14 | 0.14 | 0.14 | 0.92 | 0.88 |
| 4-Pathway/parent estrogens | 1.7 | 1.5 | 1.7 | 0.61 | 0.51 |
| 16-Pathway/parent estrogens | 0.27 | 0.29 | 0.27 | 0.90 | 0.89 |
| 2-Hydroxyestrone/16α-hydroxyestrone | 3.9 | 3.7 | 4.0 | 0.83 | 0.66 |
Adjusted for age (continuous), laboratory batch, luteal day, first morning urine, BMI (continuous), alcohol consumption, physical activity (continuous), menstrual cycle length, cycle pattern, age at first birth/parity, height, anovulatory cycle, current smoking, and average frequency of other analgesic use
a P for difference between 2+ tablets per week and 0 tablets per week