Table 1.
The baseline features of the study participants between the control and case groups
| Variables | Cases (n = 133) | Controls (n = 265) | P-value |
|---|---|---|---|
| Demographic features | |||
| Age (years) * | 49.51 ± 10.71 | 47.11 ± 10.09 | 0.032 |
| Marriage age (years) ^ | 19.0 (16.0–22.0) | 18.0 (16.0–20.0) | 0.077 |
| Age at first pregnancy (years) ^ | 20.0 (17.0–25.0) | 20.0 (17.0–22.0) | 0.055 |
| Breastfeeding time (months) ^ | 39.0 (20.0–60.0) | 48.0 (24.0–70.0) | 0.162 |
| BMI (kg/m2) ^ | 29.64 (25.96–33.32) | 28.52 (25.39–31.64) | 0.119 |
| Physical activity (MET-h/day) ^ | 32.10 (29.10–35.50) | 31.42 (29.10-34.98) | 0.677 |
| Menopausal status, % & | 0.079 | ||
|
Pre-menopause Post-menopause |
61 (45.9) 72 (54.1) |
152 (57.4) 113 (42.6) |
|
| Family history of breast cancer, yes, % & | 11 (8.3) | 12 (4.5) | 0.171 |
| Wearing a bra at day, less than 12 h, % & | 12 (9.0) | 49 (18.5) | 0.012 |
| Wearing a bra at night, yes, % & | 105 (78.9) | 189 (71.3) | 0.116 |
| Smoking history, yes, % & | 4 (3.0) | 9 (3.4) | 1.000 |
| Vitamin D, yes, % & | 20 (15.0) | 64 (24.4) | 0.038 |
| Omega-3, yes, % & | 8 (6.0) | 31 (11.7) | 0.076 |
| Herbal medicine, yes, % & | 25 (18.8) | 72 (27.2) | 0.083 |
| Dietary intakes | |||
| Energy (kcal/day) ^ |
2569.13 (2202.80-3107.85) |
2459.62 (2136.23-3220.60) |
0.615 |
| Plant protein (serving/day) ^ | 0.29 (0.18–0.50) | 0.42 (0.28–0.61) | <0.001 |
| Nuts (serving/day) ^ | 0.18 (0.08–0.35) | 0.20 (0.09–0.36) | 0.460 |
| Viscous fiber (serving/day) ^ | 1.58 (1.20–1.99) | 1.62 (1.24–2.15) | 0.202 |
| Plant MUFAs (serving/day) ^ | 1.72 (1.21–3.01) | 1.92 (1.14–3.18) | 0.229 |
| SFAs and cholesterol (serving/day) ^ | 4.75 (3.24–6.62) | 4.51 (2.78–6.33) | 0.333 |
| Phytosterols (mg/day) ^ | 20.02 (13.44–29.43) | 22.45 (15.41–30.92) | 0.123 |
| Portfolio diet score * | 17.12 ± 4.51 | 18.44 ± 4.40 | 0.005 |
Abbreviations: BMI, body mass index; kg, kilogram; m, meter; MET, metabolic equivalent of task; kcal, kilocalorie; mg, milligram; MUFAs, monounsaturated fatty acids; SFAs, saturated fatty acids
* Using independent samples T-test for parametric continuous variables, and values are mean ± SD
^ Using Mann-Whitney for non-parametric continuous variables, and values are median (25th -75th percentiles)
&Using chi-square test for categorical variables, and values are numbers (percentages)