Table 3.
Distribution of cases and controls of post-menopausal women
| Factor | No. (%)a) |
p-valueb) | Unadjusted OR (95% CI)c) | Adjusted OR (95% CI)d) | |
|---|---|---|---|---|---|
| Case (n=148, 43.1%) | Control (n=195, 56.9%) | ||||
| Age | |||||
| Mean±SD (yr) | 55.2±7.5 | 55.5±6.5 | 0.65 | ||
| Breast density (%) | |||||
| ≤ 75 | 114 (76.9) | 170 (87.1) | 0.01 | 1.0 (reference) | 1.0 (reference) |
| > 75 | 34 (23.1) | 25 (12.9) | 2.0 (1.2-3.6)* | 1.9 (1.0-3.4)* | |
| Height (cm) | |||||
| Mean±SD | 153.7±5.3 | 153.0±5.0 | 0.18 | ||
| < 155 | 82 (55.5) | 117 (60.1) | 0.39 | 1.0 (reference) | |
| ≥ 155 | 66 (44.5) | 78 (39.9) | 1.2 (0.8-1.9) | ||
| Weight (kg) | |||||
| Mean±SD | 54.1±8.2 | 53.5±7.3 | 0.51 | ||
| ≤ 54 | 75 (50.3) | 108 (55.4) | 0.35 | 1.0 (reference) | |
| > 54 | 73 (49.7) | 87 (44.6) | 1.2 (0.8-1.9) | ||
| BMI | |||||
| Mean±SD | 22.9±3.2 | 22.8±2.8 | 0.86 | ||
| < 23 | 76 (51.7) | 104 (53.2) | 0.79 | 1.0 (reference) | |
| ≥ 23 | 72 (48.3) | 91 (46.8) | 1.1 (0.7-1.6) | ||
| Age at first menstrual period (yr) | |||||
| Mean±SD | 15.4±2.2 | 15.8±2.1 | 0.15 | ||
| < 14 | 31 (21.4) | 26 (13.2) | 0.04 | 1.8 (1.0-3.2)* | 1.7 (0.9-3.1) |
| ≥ 14 | 116 (78.6) | 168 (86.8) | 1.0 (reference) | 1.0 (reference) | |
| Age at menopause (yr) | |||||
| Mean±SD | 48.6±4.8 | 49.0±4.9 | 0.38 | ||
| < 50 | 74 (50.3) | 84 (43.3) | 0.20 | 1.3 (0.9 - 2.0) | |
| ≥ 50 | 74 (49.7) | 111 (56.7) | 1.0 (reference) | ||
| Age at first birth (yr) | |||||
| Mean±SD | 25.1±4.9 | 24.3±4.8 | 0.15 | ||
| < 23 | 50 (34.9) | 83 (43.5) | 0.28 | 1.0 (reference) | |
| 23-29 | 73 (51.6) | 82 (42.9) | 1.5 (0.9-2.4) | ||
| ≥ 30 | 19 (13.5) | 25 (13.6) | 1.2 (0.6-2.5) | ||
| Age at last birth (yr) | |||||
| Mean±SD | 31.1±5.7 | 31.3±5.1 | 0.66 | ||
| < 30 | 60 (42.9) | 78 (41.3) | 0.79 | 1.0 (reference) | |
| ≥ 30 | 82 (57.1) | 112 (58.7) | 0.9 (0.6-1.5) | ||
| No. of pregnancies | |||||
| Mean±SD | 3.3±2.2 | 4.2±2.2 | < 0.001 | ||
| < 3 | 55 (38.8) | 41 (21.6) | 0.001 | 2.3 (1.4-3.7)* | 2.3 (1.4-3.7)* |
| ≥ 3 | 87 (61.2) | 149 (78.4) | 1.0 (reference) | 1.0 (reference) | |
| No. of babies born | |||||
| Mean±SD | 2.2±1.5 | 2.9±1.7 | < 0.001 | ||
| < 2 | 43 (30.1) | 29 (15.5) | 0.001 | 2.4 (1.4-4.0)* | 1.5 (0.8-2.9) |
| ≥ 2 | 99 (69.9) | 161 (84.5) | 1.0 (reference) | 1.0 (reference) | |
| No. of months of breast feeding | |||||
| Mean±SD | 14.3 ±6.7 | 14.7±6.1 | 0.51 | ||
| < 15 | 79 (55.6) | 103 (54.1) | 0.79 | 1.1 (0.7-1.7) | |
| ≥ 15 | 63 (44.4) | 87 (45.9) | 1.0 (reference) | ||
| Hormone use | |||||
| No | 115 (78) | 141 (71.9) | 0.28 | 1.0 (reference) | |
| Yes | 33 (22) | 54 (28.1) | 0.7 (0.4-1.3) | ||
| Family history of breast cancer | |||||
| No | 140 (94.6) | 181 (92.8) | 0.40 | 1.0 (reference) | |
| 1st degree | 3 (2) | 9 (4.6) | 0.4 (0.1-1.6) | ||
| 2nd degree | 5 (3.4) | 5 (2.6) | 1.3 (0.4-4.5) | ||
| Smoking | |||||
| No | 145 (98) | 192 (98.5) | 0.73 | 1.0 (reference) | |
| Yes | 3 (2) | 3 (1.5) | 1.3 (0.3-6.7) | ||
| Alcohol drinking | |||||
| No | 147 (99.3) | 192 (98.5) | 0.46 | 1.0 (reference) | |
| Yes | 1 (0.7) | 3 (1.5) | 0.4 (0.05-4.2) | ||
| Soy drinking | |||||
| < 1 Cup per day | 121 (81.8) | 166 (85) | 0.52 | 1.0 (reference) | |
| ≥ 1 Cup per day | 27 (18.2) | 29 (15) | 1.2 (0.6-2.3) | ||
| Coffee drinking | |||||
| < 1 Cup per day | 126 (84.6) | 172 (88.2) | 0.37 | 1.0 (reference) | |
| ≥ 1 Cup per day | 22 (15.4) | 23 (11.8) | 1.4 (0.7-2.7) | ||
| Vegetable consumption (servings) | |||||
| ≤ 1 | 17 (11.4) | 18 (9.2) | 0.14 | 1.0 (reference) | |
| 2-3 | 75 (50.4) | 122 (62.6) | 0.6 (0.3-1.4) | ||
| ≥ 4 | 56 (38.2) | 55 (28.2) | 1.1 (0.5-2.5) | ||
| Physical activities | |||||
| No (inactive) | 12 (8.3) | 21 (10.6) | 0.52 | 1.0 (reference) | |
| Yes (insufficient and sufficient) | 136 (91.7) | 174 (89.4) | 0.8 (0.3-1.7) | ||
OR, odds ratio; CI, confidence interval; SD, standard deviation; BMI, body mass index.
*
Statistically significant (p < 0.05).
a)
Number of participants (%),
b)
Obtained from t test for continuous variables and chi-squared test for categorical variables,
c)
Unadjusted OR (95% CI)—obtained from binary logistic regression,
d)
Multivariable adjusted OR (95% CI)—obtained from multiple logistic regression.