Table 2

Odds ratio (and 95% confidence intervals) estimates of high-risk mammographic patternsa associated with indices of physical activity, overall and by menopausal status, surveyed at a population screening, Tromsø, Norway, 1979–1980 and 1986–1987.

AllPremenopausalPostmenopausal
CrudeAdjustedCrudeAdjustedCrudeAdjusted
Hours physically activeb in 1986–1987
 Seldom/never1.01.01.01.01.01.0
 ≤2 h/wk0.90.9 (0.8–1.2)1.11.1 (0.9–1.5)0.70.6 (0.4–0.9)
 >2 h/wk0.90.8 (0.6–1.1)0.80.7 (0.5–1.1)1.00.8 (0.4–1.3)
Work-time physical activityc in 1979–1980 and 1986–1987
 Sedentary (both times)1.01.01.01.01.01.0
 Some/mixture0.71.0 (0.8–1.3)0.81.0 (0.8–1.4)0.60.9 (0.6–1.5)
 Moderate (both times)0.50.8 (0.5–1.5)0.50.8 (0.4–1.6)0.50.8 (0.4–1.7)
Leisure-time physical activity in 1979–1980 and 1986–1987
 Sedentary (both times)1.01.01.01.01.01.0
 Some/mixture1.01.1 (0.8–1.6)0.91.0 (0.7–1.5)1.41.4 (0.7–2.8)
 Moderate (both times)1.00.9 (0.5–1.7)0.80.8 (0.4–1.5)1.91.3 (0.4–4.0)
  • a Low-risk patterns are I–III (reference group) and high-risk patterns, IV and v. ORs were adjusted for age, education, number of children, body mass index, age at menarche, alcohol intake, oral contraceptive use, and menopausal status for the entire study population. Sedentary group is referent.

  • b Physically active enough to cause sweating or hard breathing.

  • c Total number for analysis was 2394 (excluding women who did not work at least part-time); for premenopausal women, 1572; for postmenopausal women, 822.