Table 4. Association between thyroid hormones and risk of overall and aggressive prostate cancer.
| Overall Prostate Cancer | Aggressive* Prostate Cancer | |||||
| # Cases/# Controls | OR (95% CI)† | OR (95% CI)‡ | # Cases/# Controls | OR (95% CI)† | OR (95% CI)‡ | |
| Thyroxine (T4) (µg/dL) | ||||||
| Q1: <6.5 | 75/163 | 1.0 (ref) | 1.0 (ref) | 9/163 | 1.0 (ref) | 1.0 (ref) |
| Q2: 6.5 - <7.4 | 78/164 | 1.03 (0.71–1.52) | 0.96 (0.65–1.44) | 18/164 | 1.97 (0.86–4.52) | 1.77 (0.74–4.26) |
| Q3: 7.4 - <8.3 | 80/160 | 1.09 (0.74–1.60) | 1.11 (0.74–1.66) | 14/160 | 1.56 (0.65–3.70) | 1.53 (0.62–3.79) |
| Q4: 8.3 - <9.2 | 82/156 | 1.17 (0.79–1.74) | 1.14 (0.75–1.74) | 16/156 | 1.82 (0.78–4.25) | 1.77 (0.73–4.28) |
| Q5: ≥9.2 | 86/157 | 1.22 (0.82–1.83) | 1.15 (0.75–1.77) | 19/157 | 2.10 (0.92–4.83) | 1.85 (0.77–4.45) |
| p-trend | 0.27 | 0.39 | 0.15 | 0.25 | ||
| Free thyroxine (Free T4) (ng/dL) | ||||||
| Q1: <1.4 | 70/170 | 1.0 (ref) | 1.0 (ref) | 14/170 | 1.0 (ref) | 1.0 (ref) |
| Q2: 1.4 - <1.6 | 83/163 | 1.26 (0.86–1.85) | 1.28 (0.85–1.92) | 17/163 | 1.26 (0.60–2.65) | 1.20 (0.56–2.58) |
| Q3: 1.6 - <1.7 | 66/138 | 1.18 (0.78–1.79) | 1.21 (0.79–1.86) | 13/138 | 1.14 (0.52–2.50) | 1.10 (0.48–2.51) |
| Q4: 1.7 - –<1.9 | 99/170 | 1.46 (0.99–2.14) | 1.55 (1.03–2.33) | 18/170 | 1.27 (0.61–2.25) | 1.04 (0.48–2.24) |
| Q5: ≥1.9 | 83/159 | 1.33 (0.88–2.01) | 1.33 (0.86–2.07) | 14/159 | 1.04 (0.48–2.25) | 0.76 (0.33–1.74) |
| p-trend | 0.16 | 0.21 | 0.97 | 0.42 | ||
| Thyroid-binding globulin (TBG) (µg/mL) | ||||||
| Q1: <16.1 | 76/155 | 1.0 (ref) | 1.0 (ref) | 13/155 | 1.0 (ref) | 1.0 (ref) |
| Q2: 16.1 - <18.7 | 77/169 | 0.93 (0.64–1.37) | 0.95 (0.64–1.42) | 10/169 | 0.71 (0.30–1.67) | 0.67 (0.27–1.64) |
| Q3: 18.7 - <21.3 | 83/152 | 1.12 (0.76–1.66) | 1.08 (0.72–1.64) | 17/152 | 1.31 (0.62–2.80) | 1.54 (0.69–3.42) |
| Q4: 21.3 - <24.4 | 84/163 | 1.07 (0.71–1.59) | 1.09 (0.71–1.67) | 21/163 | 1.52 (0.73–3.14) | 1.79 (0.82–3.89) |
| Q5: ≥24.4 | 81/161 | 1.03 (0.68–1.56) | 1.04 (0.66–1.62) | 15/161 | 1.08 (0.50–2.36) | 1.18 (0.51–2.73) |
| p-trend | 0.72 | 0.73 | 0.40 | 0.26 | ||
| Thyroid stimulating hormone (TSH) (µIU/mL) | ||||||
| Q1: <0.8 | 83/158 | 1.0 (ref) | 1.0 (ref) | 12/158 | 1.0 (ref) | 1.0 (ref) |
| Q2: 0.8–<1.1 | 84/157 | 1.02 (0.70–1.49) | 1.01 (0.68–1.50) | 18/157 | 1.55 (0.72–3.33) | 1.47 (0.66–3.29) |
| Q3: 1.1 - <1.5 | 84/167 | 0.96 (0.66–1.40) | 0.95 (0.64–1.41) | 18/167 | 1.43 (0.67–3.07) | 1.37 (0.62–3.02) |
| Q4: 1.5 - <2.2 | 83/151 | 1.04 (0.71–1.52) | 1.08 (0.73–1.62) | 15/151 | 1.35 (0.61–2.98) | 1.38 (0.59–3.19) |
| Q5: ≥2.2 | 67/167 | 0.77 (0.53–1.14) | 0.71 (0.47–1.06) | 13/167 | 1.03 (0.45–2.32) | 0.93 (0.39–2.20) |
| p-trend | 0.17 | 0.10 | 0.67 | 0.54 | ||
| Clinical thyroid status § | ||||||
| Hypothyroid | 20/75 | 0.52 (0.31–0.85) | 0.48 (0.28–0.81) | - | - | - |
| Euthyroid | 372/704 | 1.0 (ref) | 1.0 (ref) | - | - | - |
| Hyperthyroid | 9/19 | 0.92 (0.41–2.05) | 0.86 (0.37–1.99) | - | - | - |
*
- Information on cancer stage and grade available for cases diagnosed through July 2002.
†
- Conditioned on age and date of baseline blood draw.
‡
- Conditioned on age and date of baseline blood draw. Further adjusted for body mass index (kg/m2), serum concentrations of retinol, total cholesterol, alpha-tocopherol, and beta-carotene, cigarettes smoked per day, years smoked, family history of prostate cancer, physical activity, education, marital status, urban residence, total intake of energy, dietary vitamin D, fruit, vegetables, red meat, alcohol, and use of calcium supplements.
§
- Hypothyroid defined as TSH >3 µIU/mL and T4 <4.6 µg/dL. Hyperthyroid defined as TSH <0.3 µIU/mL and T4 >12 µg/dL.