Table 1.
Characteristics of breast cancer cases and controls analyzed for CoQ10 in a nested case-control study within the Shanghai Women’s Health Study (SWHS), 1997–2006.
| Characteristics | Cases (n=340) |
Controls (n=653) |
P- value# |
|---|---|---|---|
| Age at blood draw (years), mean (SD)* | 52.4 ± 9.0 | 52.4 ± 9.0 | 0.15 |
| Current hormone therapy use, n (%) | 13 (3.8) | 9 (1.4) | 0.04 |
| Education, n (%) | <0.01 | ||
| Elementary and under | 52 (15.3) | 151 (23.1) | |
| Middle school | 121 (35.7) | 267 (40.9) | |
| High school | 116 (34.2) | 168 (25.7) | |
| College and above | 50 (14.7) | 67 (10.3) | |
| Body mass index (kg/m2), mean (SD) | |||
| All Women | 24.2 ± 3.6 | 24.4 ± 3.3 | 0.29 |
| Premenopausal Women | 23.4 ± 3.2 | 23.6 ± 3.1 | 0.48 |
| Postmenopausal Women | 25.1 ± 3.7 | 25.3 ± 3.3 | 0.54 |
| Physically active, n (%) | 122 (35.9) | 222 (34.0) | 0.67 |
| Nulliparous, n (%) | 15 (4.4) | 24 (3.7) | 0.29 |
| Number of full term pregnancies, mean (SD) | 1.7 ± 1.1 | 1.8 ± 1.1 | 0.05 |
| Age @ first child birth, mean (SD) | 26.3 ± 4.1 | 25.6 ± 4.2 | 0.01 |
| Age @ menarche, mean (SD) | 14.8 ± 1.8 | 15.0 ± 1.7 | 0.03 |
| Months of breast feeding | 13.7 ± 15.6 | 16.3 ± 18.4 | <0.01 |
| Smoking status, n (%) | 0.39 | ||
| Never | 335 (98.5) | 634 (97.1) | |
| Former | 0 (0) | 1 (0.1) | |
| Current | 5 (1.5) | 18 (2.8) | |
| Mother or sister with breast cancer, n (%) | 14 (4.12) | 10 (1.5) | 0.01 |
| Alcohol use, n (%) | 0.71 | ||
| Never | 333 (97.9) | 634 (97.1) | |
| Former | 1 (0.3) | 2 (0.3) | |
| Current | 6 (1.8) | 17 (2.6) | |
| Deaths, n (%) | 40 (11.7) | 20 (3.1) | <0.01 |
| Postmenopausal, n (%) | 165 (48.5) | 320 (49.0) | 0.06 |
*
SD Standard deviation
#
Conditional logistic regression model for categorical variables or ANOVA test for continuous variables