Table 1.
Demographic anthropometric and lifestyle characteristics of participants in case and control groups
| Variables | Groups, mean (SD) | P valuea | |
|---|---|---|---|
| Case (n = 253) | Control (n = 267) | ||
| Age, y | 48.91(10.46) | 47.13(10.08) | 0.062 |
| BMI b, kg/m2 | 29.61(4.55) | 29.07(5.39) | 0.222 |
| Waist- circumference (cm) | 101.15(96.39) | 96.39(13.25) | < 0.001 |
| Physical Activity (Met.h/wk) | 33.18(6.11) | 32.70(5.20) | 0.336 |
| Smoking (yes), n (%) | 8 (3.2) | 9 (3.4) | 0.894 |
| Marriage age, y | 19.43(5.02) | 18.98(4.48) | 0.296 |
| Age at first pregnancy, y | 22.29(5.32) | 20.35(4.19) | < 0.001 |
| Child number | 2.92(1.43) | 2.54(1.59) | 0.005 |
| Abortion history (yes), n (%) | (37.2)94 | (29.2)78 | 0.049 |
| Breast cancer family history (yes), n (%) | (5.5)14 | (4.5)12 | 0.594 |
| Family history of cancer (yes), n (%) | (26.9)68 | (20.7)55 | 0.097 |
| History of benign breast diseases (yes), n (%) | (7.9)20 | (5.3)14 | 0.224 |
| Inflammatory disease history (yes), n (%) | (12.6)32 | (13.2)35 | 0.863 |
| Vitamin D supplement (yes), n (%) | (14.6)37 | (24.3)65 | 0.005 |
| Ever use of OCPc (yes), n (%) | (49.8)126 | (56)149 | 0.156 |
| Anti-inflammatory drugs use (yes), n (%) | (10.3)26 | (17.7)47 | 0.015 |
| CRPd (mg/dl) | 1.87 (0.44) | 1.02 (0.32) | 0.008 |
| Education, n (%) | 0.518 | ||
| Illiterate | (11.6)29 | (9)24 | |
| Low education | (46.6)116 | (50.4)134 | |
| Higher education | (42)105 | (40.6)108 | |
| Exposure to sunlight during the day (min) | |||
| Less than 30 min | (28.5)72 | (36)96 | 0.215 |
| 60–30 min | (32.4)82 | (25.5)68 | |
| 120–60 min | (17)43 | (17.2)46 | |
| More than 120 min | (22.1)56 | (21.3)57 | |
a Obtained from ANOVA for continuous variables and Chi-square for Categorical variables; b BMI: body mass index; c OCP: oral contraceptive pills; dCRP: C-Reactive Protein