Infant feeding, early weight gain, and risk of type I diabetes

Abstract

OBJECTIVE - To evaluate whether the increased risk of type 1 diabetes conferred by an early introduction of cow's milk supplements can be mediated by accelerated growth in formula-fed infants. RESEARCH DESIGN AND METHODS - All children ≤14 years of age who were diagnosed with type 1 diabetes from September 1986 to April 1989 were invited to participate in the study. Birth date- and sex-matched control children were randomly selected from the Finnish Population Registry. At least three weight measurements from the first year of life were obtained for 435 full-term diabetic subjects and 386 control subjects from well-baby clinics and school health care units. RESULTS - Increase in body weight was greater in the diabetic girls than in the control girls, and the difference increased from 111 g (95% CI 0-218, P = 0.04) at 1 month of age to 286 g (95% CI 123-450, P = 0.0006) at 7 months. For boys, the difference in weight between the diabetic subjects and the control subjects remained stable during infancy (difference 95 g, 95% CI -2- 205, P = 0.09). Increased weight was associated on average with a 1.5-fold risk of type 1 diabetes. Early introduction of formula feeding (<3 vs. ≥3 months) was also associated with an increased risk of type I diabetes after adjustment for the individual weight gain curve (adjusted odds ratio 1.53, 95% CI 1.1-2.2). No evidence for interaction was observed. CONCLUSIONS - These observations indicate that an early exposure to cows milk formula- feeding and rapid growth in infancy are independent risk factors of childhood type 1 diabetes.