Table 1

Mean IGF-I concentration (nmol/liter) according to the IGF-I 19CA repeat allele

IGF-I 19CA repeat alleleNo. of participantsMean (95% CIa) IGF-Ib
Two 19CA alleles270 (41%)19.7 (19.1–20.4)
One 19CA allele308 (47%)19.6 (19.0–20.2)
No 19CA alleles82 (12%)19.5 (18.3–20.6)
 Test for heterogeneityP = 0.906
 Test for linear trendP = 0.657
19CA present578 (88%)19.6 (19.2–20.1)
19CA absent82 (12%)19.5 (18.3–20.6)
 Test for heterogeneityP = 0.761
  • a CI, confidence interval.

  • b All of the values are adjusted for age (20–24, …, 65+), body mass index (<20, 20–21.9, 22–23.9, 24–25.9, 26–27.9, 28–29.9, 30+ kg/m2), dietary group (meat-eater, vegetarian, vegan), smoking status (never, past, 1–9 cigarettes/day or pipe or cigar smoker, 10+ cigarettes/day), and days between venipuncture and blood processing (1, 2, 3, 4+ days).