Objective: Diabetic women have a greater relative risk of coronary heart disease than diabetic men. However, the sex difference in the effect of fasting serum glucose levels below the diabetic range on the risk of coronary heart disease is unclear. We investigated whether the association between nondiabetic blood glucose levels and the incident risk of coronary heart disease is different between men and women. Methods: The fasting serum glucose levels and other cardiovascular risk factors at baseline were measured in 159,702 subjects (100,144 men and 59,558 women). Primary outcomes were hospital admission and death due to coronary heart disease during the 11-year follow-up. Results: The risk for coronary heart disease in women significantly increased with impaired fasting glucose levels (>= 110 mg/dL) compared to normal glucose levels (<100 mg/dL), whereas the risk for coronary heart disease in men was significantly increased at a diabetic glucose range (>= 126 mg/dL). Women had a higher hazard ratio of coronary heart disease associated with the fasting serum glucose level than men (p for interaction with sex = 0.021). Conclusions: The stronger effect of the fasting serum glucose levels on the risk of coronary heart disease in women than in men was significant from a prediabetic range (>= 110 mg/dL). (C) 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.