Table 2.
Associations between obesity, metabolic syndrome, and the risk of breast cancer in postmenopausal women who underwent a national Korean breast cancer screening program from 2009 to 2010.
| BMI, metabolic phenotype | No. participants | Person-years | No. cases | Adjusted HR (95% CI)a | P-value | Adjusted HR (95% CI)b | P-value |
|---|---|---|---|---|---|---|---|
| BMI | |||||||
| <25 kg/m2 | 1,935,800 | 16,868,556.0 | 13,749 | 1.00 | 1 | ||
| ≥25 kg/m2 | 1,159,536 | 10,083,792.0 | 9835 | 1.30 (1.26–1.33) | <0.001 | 1.26 (1.22–1.29) | <0.001 |
| MetS | |||||||
| No | 2,058,366 | 17,931,890.4 | 15,705 | 1.00 | 1 | ||
| Yes | 1,036,970 | 9,020,457.7 | 7879 | 1.16 (1.13–1.19) | <0.001 | 1.06 (1.03–1.09) | <0.001 |
| N of component of MetS | |||||||
| Per 1 increment | – | – | – | 1.06 (1.05–1.07) | <0.001 | 1.03 (1.02–1.04) | <0.001 |
| Component of MetS | |||||||
| Elevated BP | |||||||
| No | 1,697,774 | 14,787,997.2 | 13,324 | 1.00 | 1.00 | ||
| Yes | 1,397,562 | 12,164,350.9 | 10,260 | 1.06 (1.03–1.09) | <0.001 | 1.01 (0.99–1.04) | 0.405 |
| Elevated FBG | |||||||
| No | 2,017,573 | 17,589,624.6 | 15,120 | 1.00 | 1.00 | ||
| Yes | 1,077,763 | 9,362,723.5 | 8464 | 1.13 (1.10–1.16) | <0.001 | 1.08 (1.05–1.11) | <0.001 |
| High WC | |||||||
| No | 1,512,909 | 13,185,877.7 | 11,264 | 1.00 | 1.00 | ||
| Yes | 1,582,427 | 13,766,470.4 | 12,320 | 1.21 (1.18–1.24) | <0.001 | 1.06 (1.03–1.10) | 0.001 |
| Elevated TG | |||||||
| No | 2,176,753 | 18,948,154.5 | 16.737 | 1.00 | 1.00 | ||
| Yes | 918,583 | 8,004,193.5 | 6847 | 1.06 (1.03–1.09) | <0.001 | 1.01 (0.98–1.04) | 0.596 |
| Reduced HDL | |||||||
| No | 2,042,142 | 17,775,976.8 | 15,748 | 1.00 | 1.00 | ||
| Yes | 1,053,194 | 9,176,371.3 | 7,836 | 1.03 (1.00–1.06) | 0.024 | 1.02 (0.99–1.05) | 0.203 |
MetS metabolic syndrome, BP blood pressure, FBG fasting blood glucose, WC waist circumference, TG triglyceride, HDL high-density lipoprotein, HR hazard ratio, CI confidence interval.
aAdjusted for age, age at menarche, age at menopause, hormone replacement therapy use after menopause, delivery, duration of breastfeeding, oral contraceptive use, family history of any cancer, drinking frequency per week during the last 1 year, smoking, and physical activity including vigorous physical activity, moderate physical activity, and walking per week.
bAdjusted for the variables mentioned abovea and additionally mutually adjusted for BMI (<25 kg/m2, ≥ 25 kg/m2) and MetS (no, yes).