From: Plasma levels of leptin and mammographic density among postmenopausal women: a cross-sectional study
 | n | Leptin concentration (ng/ml) | Leptin concentration (ng/ml) adjusted for BMIb | P valuec | Absolute mammographic density (cm2) | Absolute mammographic density (cm2) adjusted for BMIb | P valuec |
---|---|---|---|---|---|---|---|
Age in tertiles (n = 967) | Â | Â | Â | Â | Â | Â | Â |
   55–58 years | 318 | 14.0 (12.9–15.2) | 13.4 (12.5–14.4) |  | 13.3 (11.6–15.2) | 12.6 (11.0–14.4) |  |
   59–63 years | 340 | 14.4 (13.3–15.6) | 13.6 (12.7–14.6) |  | 10.9 (9.6–12.4) | 10.3 (9.0–11.7) |  |
   64–71 years | 309 | 14.1 (13.0–15.3) | 13.4 (12.5–14.4) | 0.98 | 10.5 (9.2–12.1) | 10.1 (8.8–11.5) | 0.01 |
Number of full-term pregnancies (n = 967) | Â | Â | Â | Â | Â | Â | Â |
   0 | 69 | 14.7 (12.4–17.5) | 14.9 (12.9–17.2) |  | 19.7 (15.0–26.1) | 18.1 (13.9–23.7) |  |
   1–2 | 385 | 12.9 (12.0–13.8) | 12.6 (11.8–13.4) |  | 13.8 (12.3–15.5) | 13.0 (11.5–14.7) |  |
   3 | 309 | 14.6 (13.5–15.9) | 14.2 (13.2–15.3) |  | 11.4 (10.0–13.0) | 10.6 (9.3–12.19 |  |
   4 and more | 204 | 15.9 (14.4–17.6) | 13.8 (12.6–15.0) | 0.30 | 6.8 (5.8–8.0) | 6.8 (5.8–8.0) | <0.001 |
Age at first birth (n = 898) (82 have imputed values) | Â | Â | Â | Â | Â | Â | Â |
   < 20 years | 129 | 16.3 (14.4–18.5) | 14.4 (12.9–16.0) |  | 7.2 (5.9–8.9) | 7.1 (5.8–8.7) |  |
   20–24 years | 535 | 14.1 (13.2–15.0) | 13.2 (12.5–14.0) |  | 10.9 (9.9–12.1) | 10.2 (9.2–11.4) |  |
   >24 years | 234 | 13.1 (12.0–14.4) | 12.7 (11.7–14.0) | 0.08 | 14.2 (12.1–16.5) | 13.3 (11.4–15.5) | <0.001 |
Postmenopausal hormone use (n = 967) | Â | Â | Â | Â | Â | Â | Â |
   Current use | 253 | 13.5 (12.3–14.8) | 13.5 (12.5–14.6) |  | 16.7 (14.4–19.3) | 15.1 (13.0–17.6) |  |
   Current nonuse | 714 | 14.4 (13.6–15.2) | 13.5 (12.8–14.2) | 0.97 | 10.1 (9.2–11.0) | 9.8 (8.9–10.7) | <0.001 |
Smoking (n = 906) | Â | Â | Â | Â | Â | Â | Â |
   Current nonsmoking | 638 | 15.5 (14.7–16.4) | 14.1 (13.4–14.8) |  | 11.6 (10.6–12.8) | 11.6 (10.5–12.8) |  |
   Current daily smoking | 268 | 11.4 (10.4–12.4) | 12.4 (11.5–13.4) | 0.01 | 11.2 (9.7–13.0) | 9.4 (8.1–10.9) | 0.02 |
Alcohol consumption (100 g alcohol/month) (n = 877) | Â | Â | Â | Â | Â | Â | Â |
   No alcohol | 225 | 14.0 (12.7–15.4) | 13.1 (12.1–14.2) |  | 10.4 (8.9–12.2) | 10.4 (8.9–12.1) |  |
   Lower tertile (<0.42) | 206 | 14.5 (13.1–16.0) | 13.8 (13.0–15.1) |  | 10.5 (8.9–12.4) | 9.9 (8.4–11.7) |  |
   Mid tertile (0.42–1.1) | 213 | 15.1 (13.6–16.6) | 13.9 (12.7–15.1) |  | 10.5 (8.9–12.3) | 10.2 (8.7–12.1) |  |
   Upper tertile (>1.1) | 233 | 13.5 (12.3–14.9) | 13.7 (12.6–14.9) | 0.48 | 14.2 (12.2–16.6) | 12.7 (10.8–14.8) | 0.06 |
BMI (n = 967) | Â | Â | Â | Â | Â | Â | Â |
   <25 | 330 | 9.0 (8.4–9.6) |  |  | 16.4 (14.5–18.6) |  |  |
   25–30 | 393 | 15.1 (14.2–16.0) |  |  | 11.8 (10.5–13.3) |  |  |
   >30 | 244 | 23.8 (22.0–25.8) |  | <0.001 | 6.8 (5.8–7.8) |  | <0.001 |
Waist circumference in tertiles (n = 965) | Â | Â | Â | Â | Â | Â | Â |
   <83.6 cm | 323 | 9.1 (8.5–9.8) |  |  | 16.3 (14.3–18.5) |  |  |
   83.6–94.1 cm | 326 | 14.4 (13.4–15.4) |  |  | 12.7 (11.2–14.4) |  |  |
   >94.1 cm | 316 | 21.9 (20.4–23.5) |  | <0.001 | 7.3 (6.4–8.3) |  | <0.001 |
Mammographic nondense area in tertiles (n = 967) | Â | Â | Â | Â | Â | Â | Â |
   <120.1 cm2 | 325 | 9.8 (9.1–10.6) | 12.4 (11.5–13.4) |  | 20.3 (18.0–22.9) | 18.2 (15.8–20.9) |  |
   120.1–172.8 cm2 | 319 | 15.0 (14.0–16.2) | 14.1 (13.1–15.2) |  | 12.2 (10.8–13.8) | 11.2 (9.8–12.9) |  |
   >172.8 cm2 | 323 | 19.3 (17.9–20.8) | 14.1 (13.1–15.2) | 0.03 | 6.1 (5.4–6.9) | 6.4 (5.6–7.5) | <0.001 |
Mammographic percentage density in tertiles (n = 967) | Â | Â | Â | Â | Â | Â | Â |
   < 4.5% | 322 | 17.5 (16.2–19.0) | 13.4 (12.5–14.4) |  |  |  |  |
   4.5–15.5% | 322 | 13.8 (12.7–14.9) | 13.6 (12.7–14.6) |  |  |  |  |
   >15.5% | 323 | 11.8 (10.9–12.7) | 13.5 (12.5–14.5) | 0.9 |  |  |  |