Diabetes, Vol 49, Issue 6 912-917, Copyright © 2000 by American Diabetes Association
Cow's milk consumption, HLA-DQB1 genotype, and type 1 diabetes: a nested case-control study of siblings of children with diabetes. Childhood diabetes in Finland study group
SM Virtanen, E Laara, E Hypponen, H Reijonen, L Rasanen, A Aro, M Knip, J Ilonen and HK Akerblom
School of Public Health, University of Tampere, Finland. suvi.virtanen@uta.fi
The evidence for the putative role of cow's milk in the development of type
1 diabetes is controversial. We studied infant feeding patterns and
childhood diet by structured questionnaire (n = 725) and HLA-DQB1 genotype
by a polymerase chain reaction-based method (n = 556) in siblings of
affected children and followed them for clinical type 1 diabetes. In a
nested case-control design in a population who had both dietary and genetic
data available, we selected as cases those siblings who progressed to
clinical diabetes during the follow-up period (n = 33). For each case, we
chose as matched control subjects siblings who fulfilled the following
criteria: same sex, age within 1 year, not from the same family, the start
of the follow-up within 6 months of that of the respective case, and being
at risk for type 1 diabetes at the time the case presented with that
disease (n = 254). The median follow-up time was 9.7 years (range
0.2-11.3). Early age at introduction of cow's milk supplements was not
significantly associated with progression to clinical type 1 diabetes
(relative risk adjusted for matching factors, maternal education, maternal
and child's ages, childhood milk consumption, and genetic susceptibility
markers was 1.60 [95% CI 0.5-5.1]). The estimated relative risk of
childhood milk consumption for progression to type 1 diabetes was 5.37
(1.6-18.4) when adjusted for the matching and aforementioned
sociodemographic factors, age at introduction of supplementary milk
feeding, as well as for genetic susceptibility markers. In conclusion, our
results provide support for the hypothesis that high consumption of cow's
milk during childhood can be diabetogenic in siblings of children with type
1 diabetes. However, further studies are needed to assess the possible
interaction between genetic disease susceptibility and dietary exposures in
the development of this disease.