Background. Previous studies have shown controversial results regmding conelation between social status and risk for Type 1 diabetes mellitus (DM). Stress and infections have been shown to increase risk for Type 1 DM. We looked upon these factors in relation to risk for Type 1 DM in two countries, where incidence of the disease is very different.
Methods. Data from 0-15 years old 517 children (268 boys and 249 girls) in South-East of Sweden and 286 children (133 boys and 153 girls) in Lithuania with newly diagnosed type 1 diabetes mellitus were included into analysis. Three age and sex matched healthy controls were randomly selected. Response rate in control families in Sweden was 72.9% and in Lithuania 94.8%. Information was collected via questionnaires.
Results. Psychosocial stress and infections were risk factors for developing Type 1 DM in both countries (in Sweden OR 1.34, CI 1.01-1.79 and 1.99, CI 1.61-2.46 respectively, and in Lithuania 2.29, CI 1.59-3.32 and 1.82, CI 1.36-2.43, respectively). High social mixing of the mothers was also increasing risk for diabetes for the children in both countries (OR 1.32, CI 1.03-1.70 in Sweden and 1.45, CI 1.03-2.04 in Lithuania). Mother's age over 30 years at birth was a protective factor in Sweden (OR 0.66, CI 0.53-0.84), whereas in Lithuania it was a risk factor (OR 1.53, CI 1.14-2.06).
Conclusious. Psychosocial stress and infections are uniform risk factors, despite the various rate of incidence in the country. Other factors have more complex influence on the risk for diabetes.