Which environmental factors increase the risk for pediatric type 1 diabetes mellitus (DM)?

Updated: Jul 03, 2019
  • Author: William H Lamb, MD, MBBS, FRCP(Edin), FRCP, FRCPCH; Chief Editor: Sasigarn A Bowden, MD  more...
  • Print
Answer

Environmental factors are important, because even identical twins have only a 30-60% concordance for type 1 diabetes mellitus and because incidence rates vary in genetically similar populations under different living conditions. [25] No single factor has been identified, but infections and diet are considered the 2 most likely environmental candidates.

Viral infections may be the most important environmental factor in the development of type 1 diabetes mellitus, [26] probably by initiating or modifying an autoimmune process. Instances have been reported of a direct toxic effect of infection in congenital rubella. One survey suggests enteroviral infection during pregnancy carries an increased risk of type 1 diabetes mellitus in the offspring. Paradoxically, type 1 diabetes mellitus incidence is higher in areas where the overall burden of infectious disease is lower.

Dietary factors are also relevant. Breastfed infants have a lower risk for type 1 diabetes, and a direct relationship is observed between per capita cow's milk consumption and the incidence of diabetes. Some cow's milk proteins (eg, bovine serum albumin) have antigenic similarities to an islet cell antigen.

Nitrosamines, chemicals found in smoked foods and some water supplies, are known to cause type 1 diabetes mellitus in animal models; however, no definite link has been made with humans.

The known association of increasing incidence of type 1 diabetes mellitus with distance from the equator may now have an explanation. Reduced exposure to ultraviolet (UV) light and lower vitamin D levels, both of which are more likely found in the higher latitudes, are associated with an increased risk of type 1 diabetes mellitus. [27]


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!