Estimated risks (RR) of postmenopausal breast cancer and 95% confidence limits by serum levels of fasting glucose, insulin, IGF-I, and IGFBPs
| Ia | II | III | IV | P for trend | |
|---|---|---|---|---|---|
| Glucose | |||||
| Crude RR (95% CI) | 1.00 | 1.77 (0.79–3.95) | 2.23 (0.93–5.37) | 1.27 (0.49–3.26) | 0.52 |
| Adjusted RR (95% CI)b | 1.00 | 1.92 (0.83–4.42) | 2.65 (1.06–6.66) | 1.63 (0.59–4.46) | 0.23 |
| No. case/control | 11/61 | 21/66 | 20/55 | 12/56 | |
| Quartile cut-off (ng/ml) | ≤71 | >71–≤79 | >79–≤86 | >86 | |
| Insulin | |||||
| Crude RR (95% CI) | 1.00 | 0.56 (0.24–1.30) | 0.58 (0.25–1.33) | 0.69 (0.31–1.51) | 0.42 |
| Adjusted RR (95% CI)b | 1.00 | 0.56 (0.23–1.37) | 0.59 (0.25–1.40) | 0.85 (0.36–2.00) | 0.76 |
| No. case/control | 21/60 | 13/59 | 14/60 | 16/59 | |
| Quartile cut-off (mIU/l) | ≤6.09 | >6.09–≤8.62 | >8.62–≤12.53 | >12.53 | |
| IGF-I | |||||
| Crude RR (95% CI) | 1.00 | 0.93 (0.43–2.00) | 0.95 (0.45–2.01) | 0.56 (0.24–1.78) | 0.21 |
| Adjusted RR (95% CI)b | 1.00 | 1.04 (0.46–2.33) | 1.04 (0.48–2.25) | 0.58 (0.24–1.36) | 0.25 |
| No. case/control | 19/60 | 17/59 | 18/60 | 10/59 | |
| Quartile cut-off (ng/ml) | ≤93.36 | >93.36–≤127.53 | >122.53–≤161.14 | >161.14 | |
| Free IGF-I | |||||
| Crude RR (95% CI) | 1.00 | 0.66 (0.28–1.55) | 0.71 (0.29–1.74) | 1.41 (0.61–3.23) | 0.28 |
| Adjusted RR (95% CI)b | 1.00 | 0.61 (0.25–1.51) | 0.68 (0.27–1.70) | 1.39 (0.59–3.28) | 0.30 |
| No. case/control | 17/58 | 12/64 | 11/55 | 24/61 | |
| Quartile cut-off (ng/ml) | ≤0.79 | >0.79–≤1.03 | >1.03–≤1.39 | >1.39 | |
| IGFBP-1 | |||||
| Crude RR (95% CI) | 1.00 | 1.63 (0.73–3.62) | 0.95 (0.40–2.26) | 1.17 (0.81–3.87) | 0.33 |
| Adjusted RR (95% CI)b | 1.00 | 1.54 (0.66–3.62) | 0.85 (0.34–2.13) | 1.70 (0.70–4.15) | 0.50 |
| No. case/control | 12/60 | 19/59 | 11/60 | 22/59 | |
| Quartile cut-off (ng/ml) | ≤22.99 | >22.99–≤34.89 | >34.89–≤46.23 | >46.23 | |
| IGFBP-2 | |||||
| Crude RR (95% CI) | 1.00 | 0.85 (0.39–1.85) | 0.20 (0.06–0.64) | 1.07 (0.52–2.21) | 0.85 |
| Adjusted RR (95% CI)b | 1.00 | 0.92 (0.40–2.09) | 0.19 (0.06–0.63) | 0.87 (0.39–1.92) | 0.36 |
| No. case/control | 20/60 | 16/59 | 5/60 | 23/59 | |
| Quartile cut-off (ng/ml) | ≤264.69 | >264.69–≤394.995 | >394.995–≤517.04 | >517.04 | |
| IGFBP-3 | |||||
| Crude RR (95% CI) | 1.00 | 0.82 (0.39–1.73) | 0.89 (0.62–1.86) | 0.69 (0.30–1.60) | 0.46 |
| Adjusted RR (95% CI)b | 1.00 | 0.78 (0.35–1.71) | 0.85 (0.39–1.84) | 0.73 (0.30–1.74) | 0.53 |
| No. case/control | 17/58 | 12/64 | 11/55 | 24/61 | |
| Quartile cut-off (ng/ml) | ≤3167 | >3167–≤3676.5 | >3676.5–≤4266 | >4266 |
a Reference category.
b Adjusted for age, BMI, social and economic status, and reproductive variables.