Progression from impaired fasting glucose to type 2 diabetes mellitus among Chinese subjects with and without hypertension in a primary care setting.

Background: The progression from impaired fasting glucose (IFG) to type 2 diabetes mellitus (T2DM) in Chinese subjects, with and without hypertension, in a primary care setting was unknown.

Methods: The present retrospective multicenter 5-year (2002-2007) cohort study was performed on IFG subjects attending 23 general outpatient clinics who were identified by their elevated fasting blood glucose laboratory results. Development of T2DM was determined by physician diagnosis of T2DM or starting of oral antidiabetic drugs within 5 years. The relationship between the time of T2DM diagnosis and subject characteristics was assessed by adjusted hazard ratios (aHR) from Cox hazards model.

Results: Of the 9161 IFG subjects, 4080 (45%) were men and 5081 (55%) were women. There were 1998 subjects who developed T2DM. The 5-year cumulative incidence was 0.218, whereas the overall annual incidence rate was 5.981/100 person-years. Subjects were more likely to develop T2DM if they were hypertensive (aHR = 1.44; 95% confidence interval [CI] 1.28-1.62; P < 0.001), aged <60 years (aHR = 1.36, 95% CI 1.24-1.49; P < 0.001), female (aHR = 1.18, 95% CI 1.08-1.29; P < 0.001), and had higher fasting glucose levels (6.39 ± 0.49 vs 6.24 ± 0.43 mmol/L in the group that developed T2DM vs the group without T2DM, respectively; aHR = 2.01, 95% CI 1.83-2.20; P < 0.001).

Conclusion: Overall, more than one-fifth of IFG subjects in the primary care setting developed T2DM within 5 years. Health care professionals can target interventions to patients with risk factors for disease progression.