Exposure to Farming Environments in Early Life and Type 1 Diabetes
A Case-Control Study
- Katja Radon1,
- Doris Windstetter1,2,
- Susanne Solfrank1,
- Erika von Mutius2,
- Dennis Nowak1,
- Hans-Peter Schwarz2 and
- for the Chronic Autoimmune Disease and Contact to Animals (CAT) Study Group*
- 1Unit for Occupational and Environmental Epidemiology and Net Teaching, Institute and Outpatient Clinic for Occupational and Environmental Medicine, Munich, Germany
- 2University Children’s Hospital, Munich, Germany
- Address correspondence and reprint requests to Katja Radon, PhD, MSc, Unit for Occupational and Environmental Epidemiology and Net Teaching, Institute and Outpatient Clinic for Occupational and Environmental Medicine, Ziemssenstr. 1, 80336 Munich, Germany. E-mail:
It has been hypothesized that a stimulation of regulatory cytokines by microbial compounds reduces autoimmune as well as atopic diseases. Farm-related contact to microbial compounds protects from allergies, but no data on the association between farm contact and type 1 diabetes is available. The aim of this study was to test this association. A case-control study was conducted in five children’s hospitals. Regular contact to farm animals and potential confounders were assessed using a postal questionnaire. Eligible subjects were all prevalent cases with type 1 diabetes registered in the hospitals and hospital-based control subjects (response rate 91%). Included were children aged 6–16 years living in rural areas with German nationality (242 case and 224 control subjects). Regular contact to stables (adjusted odds ratio 1.2 [95% CI 0.5–2.7]) was not associated with type 1 diabetes. In addition, regular contact to specific farm animals was not associated with case status. There was a tendency for an inverse relationship between allergic rhinitis and type 1 diabetes (0.6 [0.3–1.1]; P = 0.11). There was no evidence that early exposure to farm animals largely decreases the risk in children for developing type 1 diabetes.
- Received May 12, 2005.
- Accepted August 18, 2005.