Table 2.
Adjusted geometric mean IGF-I concentrations and 95% CI among 1,542 control participants
| N | Adjusted geometric mean IGF-I (nmol/L)a (95% CI) |
Pheterogeneity c | Ptrend d | |
|---|---|---|---|---|
| Characteristics | ||||
| Phase I | 630 | 20.1 (18.3–22.0) | ||
| Phase II | 912 | 19.6 (18.4–20.8) | 0.74 | |
| Assay type | ||||
| DSL-10-5600 ACTIVE ELISA | 1,350 | 20.9 (20.3–21.5) | ||
| IDS-iSYS immunoassay | 192 | 13.3 (11.1–15.9) | <0.0001 | |
| Age at blood collection, y | ||||
| ≤54 | 308 | 21.6 (20.8–22.4) | ||
| 55–59 | 446 | 20.5 (19.8–21.1) | ||
| 60–64 | 520 | 19.3 (18.7–19.8) | ||
| ≥65 | 268 | 17.7 (16.8–18.7) | <0.0001 | <0.0001 |
| Height, cm | ||||
| <167.1 | 309 | 19.2 (18.5–20.0) | ||
| 167.1 | 310 | 19.3 (18.6–20.0) | ||
| 171.5 | 332 | 19.9 (19.2–20.6) | ||
| 175.0 | 311 | 19.9 (19.1–20.6) | ||
| ≥179.0 | 280 | 20.7 (19.9–21.5) | 0.07 | 0.01 |
| Weight, kg | ||||
| <71.0 | 312 | 18.7 (18.1–19.4) | ||
| 71.0 | 308 | 20.6 (19.9–21.4) | ||
| 76.5 | 312 | 20.0 (19.3–20.8) | ||
| 82.5 | 303 | 20.0 (19.3–20.8) | ||
| ≥89.5 | 307 | 19.5 (18.8–20.2) | 0.01 | 0.40 |
| BMI, kg/m2 | ||||
| ≤24.9 | 485 | 19.6 (19.0–20.1) | ||
| 25–29.9 | 793 | 20.3 (19.8–20.7) | ||
| ≥30 | 264 | 18.7 (18.0–19.5) | 0.003 | 0.34 |
| Smokingb | ||||
| Never | 489 | 20.1 (19.6–20.8) | ||
| Former | 640 | 19.7 (19.2–20.2) | ||
| Current | 389 | 19.5 (18.8–20.1) | 0.32 | |
| Alcohol consumption, g/db | ||||
| <8 | 623 | 19.8 (19.3–20.4) | ||
| 8–15 | 311 | 20.4 (19.6–21.1) | ||
| 16–39 | 370 | 20.0 (19.3–20.7) | ||
| ≥40 | 236 | 18.5 (17.7-19.3) | 0.01 | 0.08 |
| Physical activityb | ||||
| Inactive | 221 | 20.7 (19.7–21.7) | ||
| Moderately inactive | 415 | 20.2 (19.6–20.9) | ||
| Active | 693 | 20.4 (19.9–20.9) | 0.75 | 0.46 |
| Educational levelb | ||||
| Primary or equivalent | 579 | 19.2 (18.7–19.7) | ||
| Secondary | 556 | 19.9 (19.4–20.5) | ||
| Degree | 339 | 20.5 (19.7–21.2) | 0.03 | 0.01 |
| Country | ||||
| Denmark | 152 | 19.9 (18.4–21.4) | ||
| Germany | 383 | 19.8 (19.0–20.6) | ||
| Greece | 40 | 19.5 (17.5–21.7) | ||
| Italy | 145 | 20.6 (19.3–22.1) | ||
| Netherlands | 50 | 22.8 (20.8–25.1) | ||
| Spain | 200 | 20.5 (19.5–21.7) | ||
| Sweden | 192 | 13.9 (12.2–15.8) | ||
| United Kingdom | 380 | 22.3 (21.2–23.5) | 0.002 e |
Adjusted for age (<50, 50–54, 55–59, 60–64, 65–69, ≥70 years), center (1–18), batch (1–78), alcohol consumption (<8, 8–15, 16–39, ≥40 g/d, unknown), educational attainment (primary school, secondary school, higher education/degree, unknown), and body mass index (quartile cutoff points: <24.4, 24.4, 26.4, 28.7 kg/m2), where the adjustment variable is not the variable of interest; with 95% CI in parenthesis.
Unknown for some participants; number of unknowns calculated by subtracting the known total number in each group from 1,542.
P value refers to tests of heterogeneity between the logarithm of the geometric means in the separate categories (excluding unknowns) calculated by using analysis of variance.
P value refers to the test for trend obtained by treating the categorical variable as a continuous variable in the model.
P value refers to tests of heterogeneity between the logarithmof the geometric means amongst countries assayed using the DSL-10-5600 ACTIVE ELISA (i.e., excluding Umeaå , Sweden, assayed using the IDS-iSYS immunoassay).