Table 3.

Estrone, estradiol, and SHBG concentrations (geometric means, 95% CI) at baseline and 6-month follow-up, by baseline BMI

BMI < 25.0 kg/m2
Aspirin (N = 37)Placebo (N = 36)
Baseline6 moBaseline6 mo
Geometric mean (95% CI)Geometric mean (95% CI)Change (%)Geometric mean (95% CI)Geometric mean (95% CI)Change (%)Pa
Estrone, pg/mL28.2 (25.8–30.9)27.4 (25.2–29.8)−0.9 (−3.1)29.8 (27.0–33.0)29.9 (27.1–32.9)0.0 (0.0)0.55
Estradiol, pg/mL6.0 (5.3–6.8)6.2 (5.8–6.8)0.2 (3.9)6.5 (5.6–7.4)6.2 (5.7–6.7)−0.3 (−4.7)0.32
Free estradiol, pg/mL0.136 (0.119–0.156)0.142 (0.128–0.157)0.006 (4.0)0.144 (0.123–0.169)0.135 (0.121–0.151)−0.009 (−5.9)0.26
Bioavailable estradiol, pg/mL3.50 (3.07–3.99)3.61 (3.26–3.99)0.11 (3.1)3.64 (3.10–4.28)3.44 (3.08–3.83)−0.20 (−5.6)0.32
SHBG, nmol/L56.3 (50.6–62.7)57.1 (50.8–64.2)0.8 (1.4)60.4 (53.2–68.6)62.2 (55.5–69.8)1.8 (2.9)0.65
BMI 25.0–29.99 kg/m2
Aspirin (N = 21)Placebo (N = 22)
Baseline6 moBaseline6 mo
Geometric mean (95% CI)Geometric mean (95% CI)Change (%)Geometric mean (95% CI)Geometric mean (95% CI)Change (%)Pa
Estrone, pg/mL34.3 (29.4–40.0)34.4 (29.5–40.0)0.1 (0.3)35.9 (30.9–41.7)36.5 (31.5–42.2)0.6 (1.6)0.90
Estradiol, pg/mL8.1 (6.2–10.5)7.4 (6.3–8.6)−0.7 (−9.2)8.4 (7.1–9.9)9.6 (7.6–12.2)1.2 (14.4)0.15
Free estradiol, pg/mL0.206 (0.156–0.272)0.186 (0.154–0.224)−0.02 (−9.9)0.210 (0.178–0.249)0.244 (0.192–0.309)0.033 (15.9)0.13
Bioavailable estradiol, pg/mL5.26 (3.99–6.93)4.72 (3.90–5.70)−0.54 (−10.3)5.35 (4.51–6.35)6.19 (4.89–7.85)0.85 (15.8)0.12
SHBG, nmol/L41.2 (33.9–50.0)42.6 (35.1–51.7)1.4 (3.4)44.7 (39.0–51.2)43.0 (37.2–49.7)−1.6 (−3.7)0.12
BMI ≥ 30 kg/m2
Aspirin (N = 17)Placebo (N = 10)
Baseline6 moBaseline6 mo
Geometric mean (95% CI)Geometric mean (95% CI)Change (%)Geometric mean (95% CI)Geometric mean (95% CI)Change (%)Pa
Estrone, pg/mL33.9 (30.3–37.8)37.9 (33.7–42.7)4.1 (12.0)42.4 (35.2–51.1)40.4 (33.3–49.0)−2.0 (−4.7)0.22
Estradiol, pg/mL9.5 (8.1–11.3)10.7 (8.0–14.4)1.2 (12.5)10.7 (9.1–12.7)10.7 (8.6–13.4)0.0 (0.0)0.53
Free estradiol, pg/mL0.256 (0.213–0.307)0.280 (0.210–0.374)0.025 (9.6)0.284 (0.231–0.348)0.279 (0.217–0.359)−0.005 (−1.7)0.56
Bioavailable estradiol, pg/mL6.50 (5.40–7.83)7.14 (5.36–9.51)0.63 (9.7)7.20 (5.86–8.83)7.06 (5.51–9.05)−0.14 (−1.9)0.55
SHBG, nmol/L35.8 (29.5–43.4)38.3 (31.1–47.3)2.6 (7.2)37.5 (28.8–49.0)39.8 (30.5–52.0)2.3 (6.0)0.88
  • aP value, GEE model, comparing the change at 6-month follow-up from baseline between the aspirin and placebo groups, stratified by baseline BMI.