Context Dietary exposures in infancy have been implicated, albeit inconsistently,
in the etiology of type 1 diabetes mellitus (DM).
Objective To examine the association between cereal exposures in the infant diet
and appearance of islet autoimmunity (IA).
Design Birth cohort study conducted from 1994 to 2002 with a mean follow-up
of 4 years.
Setting Newborn screening for HLA was done at St Joseph's Hospital in Denver,
Colo. First-degree relatives of type 1 DM individuals were recruited from
the Denver metropolitan area.
Participants We enrolled 1183 children at increased type 1 DM risk, defined as either
HLA genotype or having a first-degree relative with type 1 DM, at birth and
followed them prospectively. We obtained exposure and outcome measures for
76% of enrolled children. Participants had variable lengths of follow-up (9
months to 9 years).
Main Outcome Measures Blood draws for the detection of insulin autoantibody, glutamic acid
decarboxylase autoantibody, or IA-2 autoantibody were performed at 9, 15,
and 24 months and annually thereafter. Children with IA (n = 34) were defined
as those testing positive for at least 1 of the autoantibodies on 2 or more
consecutive visits and who tested positive or had diabetes on their most recent
Results Children initially exposed to cereals between ages 0 and 3 months (hazard
ratio [HR], 4.32; 95% confidence interval [CI], 2.0-9.35) and those who were
exposed at 7 months or older (HR, 5.36; 95% CI, 2.08-13.8) had increased hazard
of IA compared with those who were exposed during the fourth through sixth
month, after adjustment for HLA genotype, family history of type 1 DM, ethnicity,
and maternal age. In children who were positive for the HLA-DRB1*03/04,DQB8
genotype, adjusted HRs were 5.55 (95% CI, 1.92-16.03) and 12.53 (95% CI, 3.19-49.23)
for initial cereal exposure between ages 0 to 3 months and at 7 months or
Conclusion There may be a window of exposure to cereals in infancy outside which
initial exposure increases IA risk in susceptible children.