Table 1 Baseline characteristics of participants according to the quartiles of glycemic index (GI) and carbohydrate intake
From: Dietary carbohydrate quality and risk of breast cancer among women
Case (n = 461) | Control (n = 495) | p-value a | Quartile of glycemic index)units/d) | p-valueb | ||||
|---|---|---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | |||||
No of case/controls | 110/129 | 106/133 | 122/117 | 123/116 | ||||
Age, year | 46.0 ± 10.31 | 44.05 ± 11.26 | 0.0003 | 46.7 ± 10.7 | 45.9 ± 10.7 | 43.1 ± 10.8 | 44.1 ± 10.7 | < 0.001 |
BMI (kg/m2) | 28.07 ± 5.20 | 28.87 ± 6.05 | 0.01 | 28.3 ± 4.9 | 29.0 ± 6.0 | 28.1 ± 5.9 | 28.4 ± 5.6 | 0.47 |
Physical activity (MET-h/week) | 23.09 ± 4.80 | 29.37 ± 44.19 | 0.01 | 34.1 ± 54.3 | 33.8 ± 51.6 | 20.5 ± 30.8 | 16.8 ± 22.2 | < 0.001 |
Age at menarche (years) | 13.02 ± 2.54 | 12.92 ± 2.76 | 0.28 | 12.9 ± 2.6 | 13.1 ± 2.4 | 12.7 ± 2.7 | 13.0 ± 2.7 | 0.50 |
Age at first birth (years) | 18.89 ± 8.51 | 17.3 ± 8.27 | 0.002 | 18.5 ± 8.42 | 17.8 ± 8.1 | 17.8 ± 8.6 | 18.0 ± 8.5 | 0.78 |
Menopausal status (%) | ||||||||
Premenopausal | 301(66.59) | 325 (67.15) | 0.85 | 133 (56.6) | 157 (66.8) | 170 (72.9) | 165 (70.5) | 0.01 |
Postmenopausal | 151(33.41) | 159 (32.85) | 102 (43.4) | 78 (33.1) | 63 (27.0) | 69 (29.4) | ||
Educational level (%) | ||||||||
Un university | 379 (83.85) | 406 (84.06) | 0.93 | 191 (81.6) | 203 (8.3) | 190 (81.9) | 201 (85.9) | 0.34 |
University | 73 (16.15) | 77 (15.94) | 43 (18.3) | 32 (13.6) | 42 (18.1) | 33 (14.1) | ||
Marital status (%) | ||||||||
Married | 369 (81.6) | 415 (87.0) | 0.05 | 195 (83.6) | 197 (84.9) | 196 (84.8) | 196 (84.1) | 0.97 |
Unmarried/divorced/widowed | 83 (18.3) | 62 (13.0) | 38 (16.3) | 35 (15.0) | 35 (15.1) | 37 (15.8) | ||
Family history of breast cancer (%) | 44 (9.73) | 7 (1.42) | 0.000 | 13 (5.4) | 12 (5.0) | 13 (5.5) | 13 (5.4) | 0.99 |
Oral contraceptive use (%) | 236 (53.03) | 258 (61.43) | 0.01 | 117 (53.9) | 135 (62.7) | 116 (54.9) | 126 (56.7) | 0.24 |
Current smoker (%) | 16 (3.54) | 24 (4.98) | 0.27 | 14 (5.9) | 5 (2.1) | 8 (3.4) | 13 (5.5) | 0.12 |
Alcohol use (%) | 12 (2.65) | 29 (6.00) | 0.01 | 15 (6.3) | 7 (2.9) | 14 (6.0) | 5 (2.1) | 0.05 |
Postmenopausal hormone use (%) | 2 (0.43) | 10 (2.02) | 0.02 | 3 (1.2) | 4 (1.6) | 1 (0.4) | 4 (1.6) | 0.56 |
Parity | ||||||||
Nulliparous/missing | 210 (42.42) | 204 (44.25) | 0.75 | 109 (45.6) | 97 (40.5) | 109 (45.6) | 99 (41.4) | 0.33 |
1 | 51(10.30) | 39 (8.46) | 27 (11.3) | 15 (6.2) | 22 (9.2) | 26 (10.8) | ||
2–3 | 154 (31.11) | 147 (31.89) | 69 (28.8) | 79 (33.0) | 72 (30.1) | 81 (33.8) | ||
≥ 4 | 80 (16.16) | 71 (15.40) | 34 (14.2) | 48 (20.0) | 36 (15.0) | 33 (13.8) | ||