BACKGROUND: Diabetes mellitus is a chronic metabolic disease caused by various factors,such as environmental factor,inherited factor,etc.,and its cause isn't very clear now. This study aims to investigate the risk factors mentioned above in the onset of diabetes mellitus, and is of significance in the first and second grade of prevention of diabetes mellitus.OBJECTIVE: To investigate the risk factors of type 2 diabetes mellitus to provide evidence for the proper intervention of it.DESIGN: Cross-sectional study based on diagnosis.SETTING: Department of epidemiology in a university and department of endocrinology in a university hospital.PARTICIPANTS: The subjects were residents who have resided in town and country of Dalian for more than 5 years and were elder than 40 years old. The method of stratified cluster random sampling was carried out among natural persons who were divided into two groups according to city and country. Totally 2 500 persons were taken in total and 1 250 persons were from each group. The subjects who had been diagnosed as diabetes mellitus were included.METHODS: Questionnaire survey was employed for all the subjects, including physical examinations such as height,weight,waist girth,hip girth,blood pressure,blood glucose,etc. Patients of type 2 diabetes mellitus were taken as the case group and the normal was as the control group. The unconditional univariate and multivariate logistic regression were used.MAIN OUTCOME MEASURES: Unconditional logistic regression analysis of risk factors of type 2 diabetes mellitus with single factor analysis and multivariate analysis.RESULTS: Family history of diabetes mellitus(OR = 2.339),obesity[body mass index(BMI),OR = 1.462],systolic pressure(OR = 1.016),hyperlipidemia(OR = 1.615), age(OR = 1.043) were the major risk factors for type 2 diabetes mellitus.CONCLUSION: Family history of diabetes mellitus, increase of systolic pressure,obesity,high blood lipid and age are the risk factor for type 2 diabetes mellitus. For all communities,control of body mass and high blood pressure is an important way to prevent type 2 diabetes mellitus.