Fatty liver predicts impaired fasting glucose and type 2 diabetes mellitus in Japanese undergoing a health checkup

Background and Aim: The question of whether fatty liver might predict impaired fasting glucose or type 2 diabetes mellitus in a longitudinal manner was assessed in Japanese subjects undergoing a health checkup. Methods: A total of 12 375 individuals (6799 men and 5576 women) without hyperglycemia or type 2 diabetes mellitus in 2000 and participating in 2005 were included. Multiple logistic regression analyses were performed for both sexes, adjusted for age, body mass index, elevated blood pressure or hypertension, family history of diabetes mellitus, alcohol drinking and smoking. Results: Impaired fasting glucose and type 2 diabetes mellitus were newly diagnosed in 7.6% and 1.0% of men and 3.8% and 0.5% of women, respectively, within the 5-year period. The prevalence of newly diagnosed impaired fasting glucose and type 2 diabetes mellitus was significantly higher in the participants with fatty liver than without fatty liver in both sexes. Fatty liver adjusted for the other factors was thus a risk factor for impaired fasting glucose and/or type 2 diabetes mellitus in both sexes (men odds ratio [OR] 1.91, 95% confidence interval [CI] 1.56-2.34 and women OR 2.15, 95% CI 1.53-3.01). The impact of fatty liver was stronger among the participants with a lower body mass index (men OR 0.92, 95% CI 0.86-0.99 and women OR 0.90, 95% CI 0.81-0.99, for one increment of body mass index). Conclusion: Fatty liver is an independent risk factor for impaired fasting glucose and type 2 diabetes mellitus, having a stronger impact in those Japanese with a lower body mass index undergoing a health checkup.