Multivariate adjusted mean levels of IGF-I and IGFBP-3, by category of lifestyle factor
All factors are mutually adjusted for each other plus laboratory batch and menopausal status. Ps refer to the linear trend test for ordinal variables (age, BMI, physical activity, parity) and a test of difference between extreme categories for nonordinal variables (smoking = never versus current; lactation, hormone use = never versus oral estrogen only, duration of oral estrogen + progesterone).
| . | Category definition . | IGF-I (ng/ml) . | IGFBP-3 (ng/ml) . |
|---|---|---|---|
| Age (yr) | <45 | 218 | 3974 |
| 45–49 | 199 | 3953 | |
| 50–54 | 185 | 3966 | |
| 55–59 | 177 | 3973 | |
| 60–64 | 184 | 4154 | |
| P = 0.006 | P = 0.24 | ||
| Body Mass Index (kg/m2) | <21 | 184 | 3879 |
| 21–22.9 | 192 | 3916 | |
| 23–24.9 | 197 | 4073 | |
| 25–28.9 | 192 | 4054 | |
| ≥29 | 181 | 4080 | |
| P = 0.66 | P = 0.01 | ||
| Smoking | Never | 190 | 3994 |
| Past | 195 | 4075 | |
| Current | 176 | 3847 | |
| P = 0.03 | P = 0.07 | ||
| Physical Activity (MET-hours/week) | <4 | 184 | 3961 |
| 4–11.9 | 186 | 4064 | |
| 12–24.9 | 195 | 4020 | |
| ≥25 | 194 | 3977 | |
| P = 0.07 | P = 0.79 | ||
| Parity | 0 | 212 | 4047 |
| 1 | 190 | 3939 | |
| 2 | 192 | 4048 | |
| 3 | 192 | 4016 | |
| ≥4 | 180 | 3924 | |
| P = 0.003 | P = 0.29 | ||
| Lactationa | Never | 182 | 3862 |
| Ever | 192 | 4069 | |
| P = 0.05 | P = 0.002 | ||
| Hormone useb | Never | 181 | 4239 |
| Current oral estrogen + progesterone | 143 | 3979 | |
| Current oral estrogen only | 116 | 3942 | |
| P = 0.0001 | P = 0.02 | ||
| Duration of oral estrogen + progesteroneb | <5 yr | 157 | 4123 |
| ≥5 yr | 122 | 3765 | |
| P = 0.01 | P = 0.09 |
| . | Category definition . | IGF-I (ng/ml) . | IGFBP-3 (ng/ml) . |
|---|---|---|---|
| Age (yr) | <45 | 218 | 3974 |
| 45–49 | 199 | 3953 | |
| 50–54 | 185 | 3966 | |
| 55–59 | 177 | 3973 | |
| 60–64 | 184 | 4154 | |
| P = 0.006 | P = 0.24 | ||
| Body Mass Index (kg/m2) | <21 | 184 | 3879 |
| 21–22.9 | 192 | 3916 | |
| 23–24.9 | 197 | 4073 | |
| 25–28.9 | 192 | 4054 | |
| ≥29 | 181 | 4080 | |
| P = 0.66 | P = 0.01 | ||
| Smoking | Never | 190 | 3994 |
| Past | 195 | 4075 | |
| Current | 176 | 3847 | |
| P = 0.03 | P = 0.07 | ||
| Physical Activity (MET-hours/week) | <4 | 184 | 3961 |
| 4–11.9 | 186 | 4064 | |
| 12–24.9 | 195 | 4020 | |
| ≥25 | 194 | 3977 | |
| P = 0.07 | P = 0.79 | ||
| Parity | 0 | 212 | 4047 |
| 1 | 190 | 3939 | |
| 2 | 192 | 4048 | |
| 3 | 192 | 4016 | |
| ≥4 | 180 | 3924 | |
| P = 0.003 | P = 0.29 | ||
| Lactationa | Never | 182 | 3862 |
| Ever | 192 | 4069 | |
| P = 0.05 | P = 0.002 | ||
| Hormone useb | Never | 181 | 4239 |
| Current oral estrogen + progesterone | 143 | 3979 | |
| Current oral estrogen only | 116 | 3942 | |
| P = 0.0001 | P = 0.02 | ||
| Duration of oral estrogen + progesteroneb | <5 yr | 157 | 4123 |
| ≥5 yr | 122 | 3765 | |
| P = 0.01 | P = 0.09 |