Table 3.

Adjusted geometric mean hormone levels by estimated number of aspirin tablets per month in 1988 among postmenopausal women in the Nurses' Health Study

NEstimated aspirin tablets/mo*Percent differencePtrend
01-1011-3031-5050+
Maximum n7162762471002568
Estradiol, pg/mL6947.06.97.26.76.6−4.50.45
Free estradiol, pg/mL6630.100.100.100.100.09−5.80.39
Estrone, pg/mL54524.725.224.223.422.7−7.90.04
Estrone sulfate, pg/mL687204216207213179−12.10.03
Testosterone, ng/dL69721.321.921.119.320.5−3.70.08
Free testosterone, ng/dL6810.200.220.200.190.19−6.00.12
Androstenedione, ng/dL54555.456.855.553.353.0−4.40.07
Ratio of estrone/androstenedione5220.470.480.450.450.47−0.020.68
Ratio of estradiol/testosterone6590.350.350.360.400.34−1.00.72

NOTE: Adjusted for age at blood draw, laboratory batch, fasting status at blood draw, date and time of blood draw, parity, AFB, BMI at blood draw, physical activity, smoking history, duration of PMH use among past users, age at menopause, and alcohol intake.

  • *Calculated as the midpoint of each frequency category (0, 2.5, 9.5, 18, or 26 d/mo) multiplied by the midpoint of each category of usual number of tablets taken on each day of use (0, 1, 2, 3.5, 5.5, or 7.5 tablets).

  • Percent difference for highest vs lowest category of aspirin use (50+ vs 0 tablets/mo), calculated using (eβ − 1) × 100; no statistically significant differences.

  • Weighted by the midpoint of each frequency category (0, 2.5, 9.5, 18, or 26 d/mo) multiplied by the midpoint of each category of usual number of tablets taken on each day of use (0, 1, 2, 3.5, 5.5, or 7.5 tablets); calculated using the Wald test.