FAMILY HISTORY OF DIABETIC-PATIENTS IN JAPAN

The frequency of a positive family history of diabetes in diabetic pat ients has increased in recent studies. In this study, it was 16-33% fo r type 1 diabetes and 43-49% for type 2 diabetes. It was significantly higher than in non-diabetic subjects, and in type 2 than in type 1 di abetic patients. The prevalence of diabetes in parents and siblings of type 2 diabetic patients was higher than in those of type 1 patients, and it was particularly high in parents of young onset type 2 patient s. Among type 2 diabetic patients, positive family history was somewha t lower in those with marked obesity in the past. Comparison of groups with varying degrees of glucose intolerance revealed that a family hi story of diabetes increased in parallel with the impairment of glucose tolerance. The results suggest that genetic factors in the pathogenes is of diabetes are more important in type 2 than in type 1 diabetes, a nd in the younger onset and less obese subjects than in older onset an d more obese patients for type 2 diabetes.