Relationship between serum amylase and fasting glucose (A), and HbA1c (NGSP) (B). FPG of 90 mg/dl corresponds with HbA1c of 5.0% (NGSP), as determined by linear regression analysis between FPG and HbA1c (y = 0.02x + 3.17, where y is HbA1c and x is FPG; R2 = 0.44, P < 0.0001). The numbers of subjects in six BMI groups are the same as those in Figure 1. Statistical associations were examined by one-way ANOVA and P value is significant at P < 0.0001 (A). Post hoc analysis with Bonferroni method showed that no significant difference in serum amylase was observed between any groups divided with HbA1c (B). BMI: body mass index, FPG: fasting plasma glucose, NGSP: National Glycohemoglobin Standardization Program. Bars express standard errors.