Aims: To ascertain which impaired glucose homeostasis at baseline is predictive of conversion to type 2 diabetes in both men and women in a high-risk non-diabetic population. Methods: The screening survey for type 2 diabetes was conducted in 1994, and a follow-up study of 627 high-risk non-diabetic individuals at baseline was carried out in 1999 in Beijing area. A total of 70 men and 76 women developed diabetes during the 5-year follow-up. Results: After adjustment for age, body mass index, smoking, systolic blood pressure, family history of diabetes, total cholesterol, triglycerides, antihypertensive medication, occupation, education, urine albumin excretion rate, and fasting insulin, the odds ratios for incidence of diabetes were 1.00, 2.04 (95% CI 0.84-4.97), 7.82 (2.66-2.3.00), 9.38 (3.30-26.69) in men with normal glucose, isolated IFG, isolated IGT, and both IFG and IGT, respectively. In women, the corresponding odds ratios were 1.00, 2.79 (0.91-5.30), 1.62 (0.72-3.67), and 8.79 (2.98-25.93), respectively. Conclusions: This study shows that combined IFG and IGT at baseline is a strong risk predictor for the development of diabetes in both men and women. Isolated IGT is also a predictor of diabetes in Chinese men. (C) 2004 Elsevier Ireland Ltd. All rights reserved.