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Table 1: Selected characteristics of the study population.

Variables Cases ($n=280$) (%) Controls ($n=280$) (%) $P\hspace{0.17em}{\text{value}}^1$ Age (years, mean ± SD) $51.9\pm 8.2$ $50.0\pm 9.8$ .01 <30 3 4 31–40 17 27 41–50 45 41 51–60 29 23 61+ 6 5 Education attainment (years, mean ± SD) $13.4\pm 3.0$ $12.8\pm 3.1$ .01 Marital status Single 12.5 11.1 Married/Common-law 70.4 66.4 Separated/divorced 13.9 14.6 Widowed 3.2 7.9 .15 Parity Nulliparous 27.1 15.4 .01 ≥1 72.9 84.6 .01 Menopausal status Yes 203 145 No 77 135 .01 Oral contraceptive use Ever 87.9 85.0 Never 12.1 15.0 .40 Hormone replacement therapy Yes 26.8 33.6 No 73.2 66.4 .10 Smoking Ever 63.6 53.6 Never 36.4 46.4 .02 Smoking $10.3\pm 13.4$ $7.8\pm 12.8$ .03 (pack-years, mean ± SD) Age at menarche(years, mean ± SD) $12.5\pm 1.5$ $12.7\pm 1.6$ .12 Age at menopause (years) $45.4\pm 6.9$ $45.3\pm 7.9$ .20 Age at maximum weight(years) $46.6\pm 11.9$ $39.4\pm 12.5$ .01 Current weight (lbs) $146.6\pm 25.3$ $143.1\pm 25.1$ .10 Weight at the age of 20 (lbs) $116.7\pm 16.0$ $119.9\pm 19.7$ .06 Weight at the age of 30 (lbs) $129.9\pm 21.0$ $127.4\pm 14.8$ .18 Weight at the age of 40 (lbs) $141.8\pm 28.1$ $137.4\pm 29.8$ .20 Maximum lifetime weight (lbs) $155.8\pm 26.4$ $149.9\pm 28.5$ .04 Weight gain since the age of 20 (lbs) $30.0\pm 22.6$ $23.2\pm 21.8$ .01 Weight gain since the age of 30 (lbs) $21.3\pm 20.4$ $15.0\pm 18.7$ .01 Weight gain since the age of 40 (lbs) $12.4\pm 14.9$ $6.9\pm 15.2$ .01 Physical activity (MET-hours/week) Moderate (4) $18.8\pm 13.5$ $21.8\pm 14.8$ .01 Vigorous (7) $8.1\pm 12.0$ $7.1\pm 11.0$ .29 Total $26.9\pm 20.0$ $28.9\pm 18.8$ .22 Total energy intake (Kcal) $2025.6\pm 674.2$ $1782.1\pm 626.3$ .01

${}^1\text{All}\hspace{0.17em}P$ values are univariate and derived by student’s t-test for continuous variables with the χ 2 test for categorical variables. MET: metabolic equivalent.