Skip to main content

Table 3 Associations between physical activity and volumetric mammographic density among all women

From: Background risk of breast cancer and the association between physical activity and mammographic density

Type of activity N % Absolute dense volume (cm 3 ) Nondense volume (cm 3 ) Percent dense volume (%)
    Unadjusted Adjusted Unadjusted Adjusted Unadjusted Adjusted
β (95% CI) β (95% CI) a β (95% CI) β (95% CI) a β (95% CI) β (95% CI) a
Total activity (MET-hours/day)         
 < 40.0 12,180 31.3 Reference Reference Reference Reference Reference Reference
 40.0 to 44.9 15,273 39.2 −2.7 (−3.5, −2.0) −1.2 (−2.0, −0.4) −86.9 (−97.8, −75.9) −14.6 (−23.2, −6.0) 0.5 (0.4, 0.6) 0 (−0.1, 0.1)
 45.0 to 49.9 7,591 19.2 −3.1 (−4.0, −2.2) −2.5 (−3.5, −1.5) −138.4 (−151.3, −125.5) −34.9 (−45.0, −24.9) 1.1 (0.9, 1.2) 0.1 (0, 0.2)
 ≥ 50.0 3,869 9.9 −2.4 (−3.5, −1.3) −3.4 (−4.7, −2.3) −110.7 (−127.6, −93.8) −23.7 (−36.9, −10.4) 1.0 (0.8, 1.2) 0 (−0.2, 0.2)
P global b    <0.001 <0.001 <0.001 <0.001 <0.001 0.39
 For every 5 MET-hours/day increasec    −0.9 (−1.2, −0.6) −1.1 (−1.3, −0.7) −39.0 (−43.1, −35.0) −8.5 (−12.0, −5.5) 0.3 (0.2, 0.4) 0 (−0.04, 0.04)
P trend d    <0.001 <0.001 <0.001 <0.001 <0.001 0.96
Moderate activity (hours/day)         
 < 2.0 15,104 38.8 Reference Reference Reference Reference Reference Reference
 2.0 to 4.9 12,300 31.6 −2.4 (−3.2, −1.7) −0.3 (−1.1, 0.5) −43.3 (−54.1, −32.5) −4.8 (−13.3, 3.6) 0.1 (0, 0.2) 0 (−0.1, 0.1)
 5.0 to 6.9 5,729 14.7 −1.1 (−2.0, −0.1) −1.0 (−2.1, 0) −27.6 (−41.5, −13.8) 3.1 (−7.8, 14.0) 0.1 (0. 0.3) −0.2 (−0.3, 0)
 ≥ 7.0 5,780 14.9 −1.0 (−1.9, 0) −1.9 (−2.9, −0.9) −63.1 (−77.0, −49.2) −5.1 (−15.9, 5.7) 0.7 (0.5, 0.8) −0.1 (−0.2, 0.1)
P global b    <0.001 <0.001 <0.001 0.41 <0.001 0.03
 For every 1 h/day increasec    −0.1 (−0.2, 0.02) −0.3 (−0.4, −0.1) −7.9 (−9.6, −6.2) −0.5 (−1.8, 0.8) 0.1 (0.07, 0.1) −0.02 (−0.03, 0)
P trend d    0.12 <0.001 <0.001 0.44 <0.001 0.09
Vigorous activity (hours/day)         
 < 0.25 28,559 73.4 Reference Reference Reference Reference Reference Reference
 0.25 to 0.49 6,237 16.0 −2.6 (−3.5, −1.7) −2.6 (−3.5, −1.6) −145.1 (−156.6, −133.6) −43.1 (−52.1, −34.1) 1.2 (1.1, 1.4) 0.2 (0.1, 0.4)
 0.5 to 0.9 3,226 8.3 −4.9 (−6.0, −3.8) −3.5 (−4.7, −2.3) −163.2 (−178.1, −148.3) −64.5 (−76.5, −52.5) 1.2 (1.0, 1.3) 0.4 (0.2, 0.6)
 ≥ 1.0 891 2.3 −5.3 (−7.4, −3.3) −3.1 (−5.3, −1.0) −134.9 (−164.0, −105.9) −60.6 (−82.9, −38.4) 0.9 (0.6, 1.3) 0.6 (0.3, 0.9)
P global b    <0.001 <0.001 <0.001 <0.001 <0.001 <0.001
 For every 1 h/day increasec    −5.6 (−6.5, −4.6) −3.9 (−4.9, −2.9) −181.4 (−199.9, −162.8) −62.7 (−75.6, −49.9) 1.3 (1.1, 1.5) 0.4 (0.2, 0.6)
P trend d    <0.001 <0.001 <0.001 <0.001 <0.001 <0.001
Recreational activity (hours/day)         
 < 0.5 2,282 5.9 Reference Reference Reference Reference Reference Reference
 0.5 to 0.9 5,170 13.3 −0.5 (−2.1, 1.0) −0.7 (−2.3, 1.0) −91.2 (−115.3, −67.0) −40.4 (−59.7, −21.2) 0.7 (0.4, 0.9) 0.2 (0, 0.4)
 1.0 to 2.9 20,860 53.6 −2.5 (−3.9, −1.2) −1.6 (−3.0, −0.1) −138.0 (−159.5, −116.6) −49.4 (−66.7, −32.2) 1.0 (0.8, 1.2) 0.3 (0.1, 0.5)
 ≥ 3.0 10,601 27.2 −4.3 (−5.7, −2.9) −2.5 (−4.0, −1.0) −160.7 (−183.0, −138.4) −50.5 (−68.6, −32.5) 1.1 (0.9, 1.3) 0.3 (0.1, 0.5)
P global b    <0.001 <0.001 <0.001 <0.001 <0.001 0.02
 For every 1 hour/day increasec    −0.9 (−1.1, −0.7) −0.5 (−0.7, −0.3) −19.3 (−22.1, −16.6) −4.4 (−6.7, −2.1) 0.1 (0.08, 0.1) 0.02 (0, 0.05)
P trend d    <0.001 <0.001 <0.001 <0.001 <0.001 0.09
  1. β, regression coefficient; CI, confidence interval; MET, metabolic equivalent of task. aAdjusted for age at mammography (5-year categories), body mass index (<25.0, 25.0 to 29.9, ≥30.0 kg/m2), family history of breast cancer in mother or sisters (yes, no), age at menarche (<13, 13, 14, ≥15 years), parity and age at first birth (nulliparous; one or two births, age at first birth <26 years; one or two births, age at first birth ≥26 years; ≥3 births, age at first birth <26 years; ≥3 births, age at first birth ≥26 years), oral contraceptives use (never, ever), menopausal status (premenopausal, postmenopausal), use of hormone replacement therapy (never, past, current), education level (secondary school, high school, university or higher, other), smoking status (never, past, current) and alcohol consumption (none, 0.1 to 9.9, 10.0 to 29.9, ≥30.0 g/day). b P global values were obtained from regression models using physical activity as a categorical exposure. cChange in volumetric mammographic density for every 5 MET-hours/day increase in total activity or every 1 hour/day increase in moderate, vigorous or recreational activity, respectively; from regression models using physical activity as a continuous exposure. d P trend values were obtained from regression models using physical activity as a continuous exposure.
\