Risk Factors of Incidence of Type 2 Diabetes and Cardiovascular Diseases

Methods:

We aim to perform a two-step blood glucose survey in 2008-2009 in a population selected from a single urban community of Shanghai. The Institutional Review Board of the Rui-Jin Hospital approved the study protocol. Informed consent will be obtained from each participant.

1. In the first step, we first invited all registered permanent residents aged 40 or above by local poster advertisement and by mail to participate in a screening examination, during which we collected information on lifestyle, medical history and the use of medications using a questionnaire, and performed anthropometrical measurements and fasting glucose measurement. The first step of diabetes screening finished in June, 2008.
2. In the second step, after exclusion of subjects with self-reported diabetes, we classified the screened subjects into 3 groups according to their fasting plasma glucose concentration of 7.0 mmol/L or above, 5.0 to 6.9 mmol/L or below 5.0 mmol/L. We selected randomly a sample from these 3 subgroups for further investigation including a 75-g oral glucose tolerance test (OGTT) and blood and urine sampling and other vascular functional measurements. Our selection was based on a ratio of 1:1.2:1.44, because of the concern that by knowing the results of fasting plasma glucose test, subjects with lower glucose levels might have a lower participation rate than those with higher glucose concentrations. Nevertheless, this ratio was arbitrarily chosen. Finally, 1000 Type 2 diabetic patients, 1200 subjects with IGR and 1440 subjects with normal glucose metabolism were selected as target population of this study by random sampling for further blood and urine sampling.
3. Biomarkers and genetic risk factors will be evaluated in the study subjects.