Table 3.
Associations between relative telomere length and risk of breast cancer, the Singapore Chinese Health Study
| Telomere length in quartile§ | Cases | Person-years | HR1 (95% CI) | HR2 (95% CI) |
|---|---|---|---|---|
| Q1 (0.73–0.85) | 84 | 43,035 | 1.00 (ref) | 1.00 (ref) |
| Q2 (0.92–0.99) | 106 | 44,093 | 1.21 (0.91, 1.62) | 1.22 (0.91, 1.62) |
| Q3 (1.06–1.13) | 120 | 44,312 | 1.35 (1.02, 1.79) | 1.35 (1.01, 1.78) |
| Q4 (1.23–1.40) | 132 | 45,174 | 1.45 (1.09, 1.91) | 1.47 (1.11, 1.94) |
| P trend | 0.008 | 0.006 |
CI confidence intervals, HR hazard ratio
§Numbers inside the parentheses are interquartile ranges
1Hazard ratios and P values were derived from the Cox proportional hazard regression model that included age at blood collection and dialect group (Hokkien or Cantonese)
2Hazard ratio and P values were derived from the Cox proportional hazard regression model that also included level of education (no formal education, primary school, or secondary school and above), BMI (< 18.5, 18.5 to < 23, 23 to < 27.5, 25.5+ kg/m2), age when period became regular, age at first live birth (< 10, 21–25, 26–30, or ≥ 31 years), number of live births (0, 1–2, 3–4, or ≥ 5), age at menopause (≤ 49, 50–54, or ≥ 55 years), use of hormone therapy (never, ever, or current), use of oral contraceptives (no or yes), family history of breast cancer (no or yes), smoking status (never, former, or current smoker), alcohol consumption (non-drinker, < 7 or ≥ 7 drinks per week), weekly vigorous work or strenuous sports (no or yes), and number of hours of sleep