Prevalence of changes in undiagnosed glucose intolerance according to age and gender in Japanese middle-aged working people.

BACKGROUND Undiagnosed diabetes mellitus (DM) and impaired glucose tolerance (IGT) have important health consequences. METHODS AND RESULTS To examine the prevalence of undiagnosed glucose intolerance, oral glucose tolerance tests were administered to 1,142 consecutively enrolled middle-aged subjects (age range 40-55 years; 914 men, mean 50.7 years; 228 women, mean 49.4 years) who worked in a company and underwent a health check in 2006. No subject had a history of glucose intolerance. Fasting glucose levels increased with age in both men and women, with the levels being higher in men than women at every age. Glucose intolerance was more common in men compared with women (fasting glucose 100.1 +/-19.7 vs 92.9 +/-9.6, P<0.01; 1-h 170.7 +/-52.1 vs 139.7 +/-11.6, P<0.01; 2-h 136.0 +/-50.1 vs 119.8 +/-31.5 mg/dl, P<0.01). The prevalence of IGT and DM was also higher in men than in women (IGT: 24.1 vs 16.7, P<0.01; diabetes 10.7 vs 1.4%, P<0.01). CONCLUSIONS Fasting glucose levels increased with age in both men and women, with levels being higher in men than in women at every age. The prevalences of undiagnosed IGT and type 2 DM were also higher in men than in women.