The hypothesis for this study is that weaning to an extensively hydrolyzed infant formula will decrease the incidence of type 1 diabetes in subjects with risk-associated HLA genotypes and a first degree relative with type 1 diabetes, as it does in all relevant animal models for the disease.
Specific Aims:
I.a: To determine if weaning to a casein hydrolysate infant formula reduces the frequency of diabetes-predictive auto-antibodies in subjects with risk-associated HLA genotype and a first degree relative with type 1 diabetes (mother, father and/or full sibling).
I-b: To determine if weaning to a casein hydrolysate infant formula reduces the frequency of clinical diabetes in subjects with risk-associated HLA genotype and an affected first degree relative.
A secondary aim is to determine relationships between cow's milk antibodies, a measure of cow's milk exposure, and diabetes-associated auto-antibodies.
The mother of the unborn child is recruited during pregnancy. Randomization to one of two infant formulas takes place before birth (after 35 weeks gestation) or immediately after birth.
Experimental Arm: Use of extensively hydrolysed cow's milk based infant formula when needed in supplementation or substitution for breast milk through 6-8 months from birth.
Control Arm: Use of non-hydrolysed cow's milk based infant formula when needed in supplementation or substitution for breast milk through 6-8 months from birth.
All families were encouraged to breast feed their infants for as long as possible. The study infant formula was only used if exclusive breast feeding ceases before 8 months of age.
Cord blood for genotyping was obtained at birth, or failing that from a heel prick by 7 days of age. Only subjects with genotypes indicating increased genetic risk for type 1 diabetes remained in the intervention trial. All other subjects were withdrawn from the study.
All subjects were followed until the youngest subject turns age 10 years.