Type 2 diabetes is the most common cause of hyperglycemia. It has different prevalence in various populations. It has been found out that type 2 diabetes is a genetic disorder; however, its inheritance and its type have not been well defined. In studying the genes involved in the development of diabetes, several genes have been introduced as candidates; however, the gene or genes involved in diabetes cannot be identified yet. As family diabetes has not been studied in Iran so far, this study was conducted on a population aged over 20 years in east of Tehran. In a population of 14,687 people living in east of Tehran, 180 families with type 2 diabetes were identified. In this research, 802 subjects were female and 792 were male. After oral glucose tolerance test, 40.7% of females and 32.3% of males had diabetes. The incidence of diabetes in females was significantly higher than that in males (P < 0.001). It was found that 656 diabetic patients had age over 20 years, which most of them had age between 41 and 70 years. The highest number of diabetic patients was in the age group of 51-60 years. The percentage of offspring and siblings involvement in this sample was 44% and 53%, respectively. The highest level of involvement among the first-degree family members belonged to sister-brother, followed by father-daughter. This study shows the relationship between family diabetes in Iranian families in a demographic study. By recognizing the family relations, effective measures can be taken to prevent this disease. In the case of type 2 diabetes development in one member of family, the incidence of diabetes in other family members would increase by up to 50%. Thus, screening is suggested for all type 2 diabetic family members continuously so that the disease to be immediately diagnosed and treated to prevent major complications of diabetes.
Keywords: Epidemiology; familial diabetes; type 2 diabetes.