Extra weight gain during the first year of life is associated with an increased risk of type 1 diabetes, according to research that points to early environmental origins for the disease.
An analysis of data from two population-based cohorts – representing a total of 99,832 children from Norway and Denmark – showed each 1–standard deviation increase in weight from birth to 1 year of age was associated with a 24% increase in the risk of type 1 diabetes, even after adjustment for potential confounding factors such as birth weight, sex, maternal body mass index, maternal diabetes, and breastfeeding duration.
However, the study did not find an association between increase in the baby’s length from birth to 1 year and type 1 diabetes risk.
The association between growth rate and type 1 diabetes risk was significant only for the first half-year of life, and the data did not find a significant relationship between peak weight velocity and type 1 diabetes risk (JAMA Pediatrics 2015 Dec 7. doi: 10.1001/jamapediatrics.2015.3759).
The authors said the evidence did not support a strong role for genetic and epigenetic factors, and they also accounted for other potential environmental factors such as infant feeding.
“A general mechanism that may plausibly explain our findings is that rapid growth increases the demand on beta cells to secrete insulin, and it has been shown that beta cells actively secreting insulin are more susceptible to cytokine damage in vitro,” wrote Maria C. Magnus, Ph.D., of the Norwegian Institute of Public Health, and her coauthors.
The cohort studies were supported by the National Institutes of Health and the Norwegian Research Council March of Dimes Birth Defects Foundation, the Danish Heart Association, the Danish National Research Foundation, the Danish Pharmaceutical Association, the Ministry of Health, and the National Board of Health. No other conflicts of interest were declared.