Customize your JAMA Network experience by selecting one or more topics from the list below.
Virtanen SM, Takkinen H, Nwaru BI, et al. Microbial Exposure in Infancy and Subsequent Appearance of Type 1 Diabetes Mellitus–Associated Autoantibodies: A Cohort Study. JAMA Pediatr. 2014;168(8):755–763. doi:10.1001/jamapediatrics.2014.296
The role of microbial exposure during early life in the development of type 1 diabetes mellitus is unclear.
To investigate whether animal contact and other microbial exposures during infancy are associated with the development of preclinical and clinical type 1 diabetes.
Design, Setting, and Participants
A birth cohort of children with HLA antigen–DQB1–conferred susceptibility to type 1 diabetes was examined. Participants included 3143 consecutively born children at 2 hospitals in Finland between 1996 and 2004.
The following exposures during the first year of life were assessed: indoor and outdoor dogs and cats, farm animals, farming, visit to a stable, day care, and exposure to antibiotics during the first week of life.
Main Outcomes and Measures
Clinical and preclinical type 1 diabetes were used as outcomes. The latter was defined as repeated positivity for islet-cell antibodies plus for at least 1 of 3 other diabetes-associated autoantibodies analyzed and/or clinical type 1 diabetes. The autoantibodies were analyzed at 3- to 12-month intervals since the birth of the child.
Children exposed to an indoor dog, compared with otherwise similar children without an indoor dog exposure, had a reduced odds of developing preclinical type 1 diabetes (adjusted odds ratio [OR], 0.47; 95% CI, 0.28-0.80; P = .005) and clinical type 1 diabetes (adjusted OR, 0.40; 95% CI, 0.14-1.14; P = .08). All of the other microbial exposures studied were not associated with preclinical or clinical diabetes: the odds ratios ranged from 0.74 to 1.58.
Conclusions and Relevance
Among the 9 early microbial exposures studied, only the indoor dog exposure during the first year of life was inversely associated with the development of preclinical type 1 diabetes. This finding needs to be confirmed in other populations.
Create a personal account or sign in to: