Table 1.
Basic characteristics of study participants according to breast feeding duration
| Characteristic | Duration of breast feeding (mo) |
P-value* | |||
|---|---|---|---|---|---|
| 0–18 (n=163) | 19–36 (n=408) | 37–72 (n=673) | >72 (n=783) | ||
| Age (y) | 66.3±0.5 | 66.1±0.3 | 68.9±0.3 | 74.2±0.3 | <0.001 |
| Education (%) | |||||
| ≤Middle school | 96 (63.4) | 322 (82.4) | 611 (92.3) | 767 (99.3) | <0.001 |
| ≥High school | 66 (36.5) | 85 (17.6) | 61 (7.7) | 13 (0.7) | |
| House income (%) | |||||
| Low | 101 (37.8) | 278 (70.9) | 480 (72.1) | 619 (79.6) | <0.001 |
| High | 29 (32.2) | 124 (29.1) | 185 (27.9) | 154 (20.4) | |
| Current smoking (%) | 9.3±2.9 | 4.0±1.1 | 4.1±1.0 | 3.0±0.8 | 0.002 |
| Binge drinking (%) | 16.5±3.8 | 12.3±2.2 | 9.9±1.6 | 9.1±1.4 | <0.001 |
| Regular exercise (%) | 12.5±3.1 | 17.2±2.3 | 14.6±1.7 | 16.3±1.7 | <0.001 |
| Obesity (%) | 35.5±4.4 | 41.4±3.1 | 39.9±2.4 | 38.7±2.3 | <0.001 |
| Osteoporosis (%) | 32.9±4.8 | 36.5±3.7 | 47.8±3.1 | 59.5±2.9 | <0.001 |
| Sarcopenia (%) | 29.2±4.8 | 27.7±3.4 | 24.9±2.7 | 22.8±2.6 | <0.001 |
| Total energy intake (kcal) | 1,697.3±54.2 | 1,584.4±30.4 | 1,496.6±24.0 | 1,409.9±1.1 | <0.001 |
| Protein intake (g) | 56.3±2.1 | 52.8±1.6 | 47.5±1.0 | 42.5±1.1 | <0.001 |
| Menarche (y) | 16.0±0.2 | 16.2±0.1 | 16.5±0.1 | 16.7±0.4 | <0.001 |
| Menopause (y) | 49.7±0.4 | 49.3±0.3 | 48.8±0.3 | 48.1±0.2 | <0.001 |
| Hormone replace therapy (%) | 18.6±3.0 | 19.2±2.2 | 11.8±1.5 | 4.3±0.8 | <0.001 |
| Breast feeding duration (mo) | 11.0±0.4 | 31.0±0.4 | 58.1±0.5 | 128.6±1.6 | <0.001 |
| No. of deliveries | 2.4±0.1 | 2.7±0.1 | 3.7±0.1 | 5.3±0.1 | <0.001 |
| Age at first delivery (y) | 26.1±0.4 | 24.4±0.2 | 23.0±0.2 | 21.4±0.1 | <0.001 |
| Age at last delivery (y) | 30.1±0.4 | 29.4±0.3 | 31.4±0.2 | 34.2±0.2 | <0.001 |
| Duration from last delivery (y) | 36.2±0.6 | 36.7±0.4 | 37.5±0.3 | 40.1±0.3 | <0.001 |
Values are presented as mean±standard error or number (%).
*
Analyzed using age-adjusted analysis of covariance.