• Type 1 diabetes mellitus assessed by (1) blood glucose and HbA1c at 12 and 18 months of age, and annually from age 2 to 10 years, and (2) oral glucose tolerance test at 6 and 10 years of age. [ Time Frame: 12 and 18 months and annually from 2 to 10 years ] [ Designated as safety issue: No ]
  

• Diabetes associated islet antibodies (ICA, IAA, GADA, IA-2A) at 3, 6, 9, 12 and 18 months of age, and annually from age 2 to 10 years [ Time Frame: 3, 6, 9, 12, 18 months and annually from 2 to 10 years ] [ Designated as safety issue: No ]
  

Dietary Supplement: hydrolysed vs nonhydrolysed infant formula vs breast feeding
hydrolysed vs nonhydrolysed infant formula vs breast feeding

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 case in 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 are encouraged to breast feed their infants for as long as possible. The study infant formula is only used if exclusive breast feeding ceases before 8 months of age.

Cord blood for genotyping is 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 remain in the intervention trial. All other subjects are withdrawn from the study.

All subjects will be followed for 10 years.