FAMILY HISTORY AND RISK OF INSULIN-DEPENDENT DIABETES-MELLITUS - A POPULATION-BASED CASE-CONTROL STUDY

Insulin-dependent diabetes mellitus (type 1) is a common chronic disea se of childhood occurring throughout the world. In the literature, its most important determinants include genetic, environmental and famili al factors. We evaluated family history as a determinant of the risk o f type 1 diabetes mellitus with a population-based case-control study. Information about type 1 patients was taken from the dedicated regist er of the Abruzzo Region; the register has been collecting incident ca ses in the age group 0-14 years, diagnosed between 1 January 1990 and 31 December 1996. The control group was taken from the lists of patien ts attending family pediatricians. The family history data for type 1 and type 2 patients was obtained by a questionnaire, administered to t heir parents. The risk of type 1 diabetes mellitus associated with its Occurrence in first-and second-degree relatives was estimated using l ogistic regression methods. Our results show that the risk is indeed i ncreased with a positive family history (OR=3.96; 95% CI 1.54-10.14). This shows that the risk of type 1 diabetes mellitus for children whos e fathers are affected by the disease is 11 times higher with respect to controls. Moreover, the risk for children whose brothers are affect ed by the disease is 20 times higher with respect to controls. In cont rast, a family history for type 2 diabetes mellitus does not influence the risk.