Table 2.
Clinical and reproductive characteristics by BMI quartile among breast cancer cases and controls
| Study characteristics | 1st quartile: BMI ≤ 22.5 N = 177 |
2nd quartile: BMI > 22.5 - ≤ 25.6 N = 181 |
3rd quartile: BMI > 25.6 - ≤ 29.8 N = 174 |
4th quartile: BMI > 29.8 N = 173 |
P-value |
|---|---|---|---|---|---|
| Case status | .10 | ||||
| Case | 117 (66.1%) | 110 (60.8%) | 99 (56.9%) | 93 (53.8%) | |
| Control | 60 (33.9%) | 71 (39.2%) | 75 (43.1%) | 80 (46.2%) | |
| Demographics | |||||
| Age (years)a | 46.0 (37.0, 55.0) | 48.0 (40.0, 58.0) | 47.5 (41.0, 56.0) | 52.0 (44.0, 59.0) | < .001 |
| Clinical characteristics | |||||
| Height, cm a | 161.0 (156.0, 164.5) | 160.0 (156.0, 164.0) | 160.0 (155.0, 163.8) | 160.0 (156.0, 164.1) | .69 |
| Weight, kg a | 52.0 (48.5, 55.0) | 62.0 (58.0, 64.9) | 70.9 (66.0, 74.8) | 85.9 (80.0, 94.0) | < .001 |
| High blood pressure at enrollment | 32 (18.1) | 68 (37.6) | 65 (37.4) | 64 (37.0) | < .001 |
| Systolic BP a | 121.7 (109.3, 132.0) | 127.0 (114.7, 145.7) | 129.0 (116.7, 147.7) | 132.0 (119.7, 148.7) | < .001 |
| Diastolic BP a | 76.0 (66.7, 84.0) | 78.3 (68.7, 89.3) | 79.2 (72.3, 88.3) | 80.3 (74.7, 89.7) | < .001 |
| Prior diabetes diagnosis | .21 | ||||
| Yes | 7 (4.0%) | 15 (8.3%) | 11 (6.3%) | 16 (9.3%) | |
| No | 159 (89.8%) | 156 (86.2%) | 143 (82.2%) | 143 (82.7%) | |
| Missing | 11 (6.2%) | 10 (5.5%) | 20 (11.5%) | 14 (8.1%) | |
| Prior hypertension diagnosis | 32 (21.6%) | 41 (28.5%) | 55 (37.2%) | 65 (48.1%) | < .001 |
| Reproductive history | |||||
| Age at menarche a | 15.0 (14.0, 16.0) | 15.0 (14.0, 16.0) | 15.0 (14.0, 16.0) | 15.0 (14.0, 17.0) | .54 |
| Ever pregnant | 161 (91.0%) | 170 (93.9) | 166 (95.4) | 171 (98.8) | .01 |
| Number of pregnancies a,b | 4.0 (3.0, 6.0) | 4.0 (3.0, 6.0) | 4.0 (3.0, 6.0) | 5.0 (4.0, 6.0) | .15 |
| Number of births a,b | 3.0 (2.0, 5.0) | 4.0 (3.0, 5.0) | 4.0 (2.0, 5.0) | 4.0 (3.0, 5.0) | .13 |
| Menopausal status | .06 | ||||
| Pre- or peri-menopause | 97 (54.8%) | 87 (48.1%) | 86 (49.4%) | 70 (40.5%) | |
| Post-menopause | 80 (45.2%) | 94 (51.9%) | 88 (50.6%) | 103 (59.5%) | |
| Ever used HRT | .009 | ||||
| Yes | 4 (2.3%) | 10 (5.5%) | 11 (6.3%) | 19 (11.0%) | |
| No | 159 (89.8%) | 153 (84.5%) | 152 (87.4%) | 141 (81.5%) | |
| Missing | 14 (7.9%) | 18 (9.9%) | 11 (6.3%) | 13 (7.5%) | |
Where applicable, missing values were not used to generate the p-value
aMedian, (Q1, Q3)
bAmong those who were ever pregnant