Underestimation of impaired glucose tolerance and usefulness of a continuous glucose monitoring system in chronic liver disease

Background and Aim The prevalence of glucose intolerance in chronic liver disease patients is high, but glucose intolerance may be overlooked in a single blood test. The purpose of this study is to evaluate blood glucose variability in patients with chronic liver disease by a continuous glucose monitoring system (CGMS) and to examine the discrepancy between hemoglobin A1c (HbA1c) levels estimated from average blood glucose levels and HbA1c. Methods This study included 335 patients with chronic liver disease associated with glucose intolerance. A fasting blood test and 72‐h CGMS were performed. The estimated HbA1c was calculated from the average blood glucose level, and the correlation between hepatic functional reserve and blood glucose‐related parameters was analyzed. From the obtained data, we created a new formula to calculate HbA1c without using CGMS. Results As hepatic functional reserve decreased, average blood glucose and insulin resistance increased while HbA1c decreased (P