Table 2

Adjusteda mean serum concentrations (SE) of IGF-I and IGFBP-3 by smoking and age subgroups or lung cancer cases and controls (N = 456)

N (%)IGF-I Mean ng/mL (SE)IGFBP-3 μg/mLIGF-I:IGFBP-3
 Former/never-smokers207 (45.4)155.0 (3.8)29.8 (0.6)5.3 (0.1)
  Age (yrs)
   <6054 (26.1)169.3 (6.9)31.0 (1.1)5.6 (0.2)
   60–6565 (31.4)155.0 (6.2)28.6 (1.0)5.6 (0.2)
   65+88 (42.5)149.5 (5.3)29.0 (0.8)5.3 (0.2)
  P for trend0.030.200.17
 Current smokers249 (54.6)154.4 (3.5)29.8 (0.5)5.3 (0.1)
  Age (yrs)
   <6097 (39.0)155.3 (5.9)30.0 (0.8)5.3 (0.2)
   60–6580 (32.1)153.3 (6.4)30.9 (0.9)5.1 (0.2)
   65+72 (28.9)150.3 (6.8)29.6 (1.0)5.2 (0.2)
  P for trend across age groups0.580.810.73
  P for current vs. former smokers0.921.000.71
  • a Means are adjusted for sex and pack-years of smoking.