A case-control study on risk factors for Type 1 diabetes in Taipei City.

To search for non-genetic risk factors for Type 1 diabetes among Chinese, a total of 117 Type 1 diabetes patients identified from the Taipei Type 1 Diabetes Registry and 193 frequency-matched controls with normal glucose tolerance were recruited. The controls were selected from classmates or colleagues of cases with similar distributions of age, sex, and parental and individual educational levels. Information on Type 1 diabetes risk factors was obtained through standardized interviews according to a structured questionnaire administered by two trained nurses. In the univariate analyses, the order of pregnancy of the study subject, the number of spontaneous and induced abortions reported by the mother before giving birth to the study subjects, the duration of breast-feeding and monthly family income were significantly associated with Type 1 diabetes in a dose-response manner. There was a U-shaped relationship with Type 1 diabetes for birth weight and paternal age at the conception of the study subjects. After further adjustment for multiple risk factors through logistic regression analysis, the biological gradient for pregnancy order, duration of breast-feeding, and the U-shaped relationship for paternal age remained statistically significant.