Detection of Prediabetes and Undiagnosed Type 2 Diabetes: A Large Population-Based Study

Objective: Prediabetes and undiagnosed diabetes have been commonly ignored. We aimed to investigate the prevalence of prediabetes and undiagnosed type 2 diabetes mellitus, and to verify the hypothesis that vascular risk factors (VRFs) may indicate prediabetes and undiagnosed type 2 diabetes. Methods: A total of 7567 adults, who were 20 to 79 years of age, and living in Tianjin, China, participated in this study. Type 2 diabetes was assessed based on medical history, hypoglycemic drugs use, fasting plasma glucose level >= 7.0 mmol/L, or postprandial 2-hour plasma glucose level >= 11.1 mmol/L. Undiagnosed type 2 diabetes was defined among subjects with type 2 diabetes when neither a medical history of diabetes nor hypoglycemic drugs use was present. Prediabetes was ascertained as fasting plasma glucose level of 6.1 to 6.9 mmol/L, or postprandial 2-hour plasma glucose level of 7.8 to 11.0 mmol/L (WHO 1999) among diabetes-free participants. Data were analyzed using multinomial logistic regression with adjustment for potential confounders. Results: Of all participants, 655 (8.7%) had prediabetes, and 721 (9.5%) were patients with type 2 diabetes, including 321 (4.2%) undiagnosed type 2 diabetes accounting for 44.5% patients with diabetes. The prevalence of prediabetes and undiagnosed type 2 diabetes increased with age, and was higher in women than in men. In a fully adjusted multinomial logistic regression model, hypertension, overweight, obesity, central obesity, and family history of diabetes were significantly associated with prediabetes and undiagnosed diabetes, whereas physical inactivity was independently related to undiagnosed diabetes. Conclusion: The prevalence of prediabetes and undiagnosed diabetes is approximately 13%, and almost 45% of patients with diabetes are undiagnosed. VRFs, such as hypertension, high adiposity, and family history of diabetes can be indicators for detecting prediabetes and undiagnosed diabetes. (C) 2012 Canadian Diabetes Association