Table 3. Serum concentrations of IGF-I, IGF-II, IGFBP-3 and the molar IGF-I/ IGFBP-3 ratio by smoking characteristics in men and women.
|
Mean concentrations (s.d.) |
|||||
|---|---|---|---|---|---|
| n | IGF-I (ng ml−1) | IGF-II (ng ml−1) | IGFBP-3 (ng ml−1) | IGF-I/IGFBP-3 | |
| Men | |||||
| Number of cigarettes daily | |||||
| Never (zero) | 91 | 200 (62) | 833 (181) | 3192 (549) | 0.225 (0.053) |
| 1–14 cigarettes | 18 | 180 (68) | 799 (209) | 2959 (562) | 0.220 (0.065) |
| 15–24 cigarettes | 17 | 190 (54) | 799 (165) | 2921 (714) | 0.237 (0.053) |
| ⩾25 cigarettes | 10 | 178 (77) | 831 (211) | 2771 (566) | 0.233 (0.071) |
| Model A, P for trend | 0.20 | 0.61 | 0.005 | 0.51 | |
| Model B, P for trend | 0.11 | 0.43 | 0.002 | 0.62 | |
| Model C, P for trend | 0.76 | 0.14 | 0.007 | — | |
| Current smokers, pack-years | |||||
| Never (zero) | 91 | 200 (62) | 833 (181) | 3192 (549) | 0.225 (0.053) |
| 1–20 | 15 | 181 (70) | 839 (179) | 2929 (623) | 0.223 (0.064) |
| 21–39 | 13 | 184 (67) | 690 (194) | 2794 (596) | 0.237 (0.063) |
| ⩾40 | 17 | 185 (61) | 867 (172) | 2963 (649) | 0.229 (0.061) |
| Model A, P for trend | 0.22 | 0.65 | 0.02 | 0.66 | |
| Model B, P for trend | 0.15 | 0.48 | 0.009 | 0.70 | |
| Model C, P for trend | 0.87 | 0.24 | 0.03 | — | |
| Women | |||||
| Number of cigarettes daily | |||||
| Never (zero) | 110 | 174 (56) | 892 (194) | 3282 (615) | 0.192 (0.050) |
| 1–9 cigarettes | 10 | 154 (47) | 883 (124) | 3347 (403) | 0.168 (0.039) |
| 10–19 cigarettes | 17 | 165 (49) | 873 (191) | 3221 (576) | 0.194 (0.050) |
| ⩾20 cigarettes | 13 | 167 (56) | 850 (237) | 3020 (811) | 0.209 (0.054) |
| Model A, P for trend | 0.42 | 0.43 | 0.21 | 0.95 | |
| Model B, P for trend | 0.49 | 0.46 | 0.18 | 0.79 | |
| Model C, P for trend | 0.94 | 0.86 | 0.25 | — | |
| Current smokers, pack-years | |||||
| Never (zero) | 110 | 174 (56) | 892 (194) | 3282 (615) | 0.192 (0.050) |
| 1–18 | 13 | 163 (46) | 893 (137) | 3345 (473) | 0.175 (0.043) |
| 19–38 | 14 | 159 (51) | 857 (194) | 3196 (558) | 0.179 (0.048) |
| ⩾39 | 13 | 167 (56) | 850 (237) | 3020 (811) | 0.203 (0.052) |
| Model A, P for trend | 0.35 | 0.38 | 0.19 | 0.95 | |
| Model B, P for trend | 0.47 | 0.41 | 0.17 | 0.81 | |
| Model C, P for trend | 0.94 | 0.92 | 0.24 | — | |
s.d.=standard deviation.
Pack-years were divided into tertiles based on the distribution of all current smokers for men and women.
Multiple linear regression model A: unadjusted.
Model B: adjusted for age, ethnicity, height, body mass index and current HRT status in women.
Model C: adjusted for age, ethnicity, height, body mass index, current HRT status in women and IGFBP-3 for IGF-I and IGF-II as dependent variables, and IGF-I for IGFBP-3 as dependent variable.