Table 5

Mean concentration of IGF-I, IGFBP-1 and IGFBP-2 by diet group after additional adjustment for selected nutrients

Back-transformed means with 95% CIs (in parentheses).

AdjustmentsMeat-eatersVegetariansVegansTest for heterogeneity
IGF-Ia30.8 (29.1–32.6)31.3 (29.6–33.0)27.1 (25.5–28.7)0.0007
 Animal plus soya protein30.3 (27.8–33.1)30.5 (28.7–32.4)28.3 (26.1–30.7)0.325
 Nonsoya plant protein30.4 (28.5–32.5)31.2 (29.5–33.0)27.5 (25.6–29.6)0.036
 Saturated fat30.9 (29.1–32.8)31.2 (29.5–33.1)27.0 (25.2–29.0)0.011
 Nonstarch polysaccharides30.7 (29.0–32.6)31.4 (29.7–33.1)27.1 (25.4–28.8)0.002
IGFBP-1a0.96 (0.82–1.12)0.89 (0.76–1.04)1.24 (1.05–1.46)0.011
 Animal plus soya protein0.99 (0.75–1.24)0.89 (0.75–1.06)1.23 (0.98–1.54)0.073
 Nonsoya plant protein1.07 (0.89–1.29)0.89 (0.76–1.04)1.10 (0.90–1.34)0.136
 Saturated fat1.06 (0.90–1.25)0.94 (0.80–1.10)1.05 (0.86–1.27)0.522
 Nonstarch polysaccharides1.03 (0.87–1.21)0.89 (0.76–1.04)1.14 (0.96–1.36)0.118
 Zinc0.94 (0.80–1.10)0.91 (0.78–1.06)1.23 (1.04–1.45)0.021
IGFBP-2a11.7 (10.3–13.2)13.0 (11.6–14.6)15.4 (13.8–17.2)0.0049
 Animal plus soya protein13.4 (11.1–16.0)12.6 (11.0–14.3)13.9 (11.7–16.2)0.600
 Nonsoya plant protein11.9 (10.3–13.7)13.1 (11.7–14.7)15.0 (13.0–17.2)0.154
 Saturated fat11.7 (10.2–13.3)13.1 (11.6–14.7)15.4 (13.4–17.5)0.038
 Nonstarch polysaccharides11.8 (10.3–13.4)13.0 (11.5–14.5)15.3 (13.5–17.2)0.029
  • a Values are adjusted for age (10 categories), BMI (4 categories), assay batch (4 categories), time of day at venipuncture (4 categories), time since last meal at venipuncture (4 categories), days between venipuncture and processing (4 categories), and (ln)total energy intake.