The present studies examined the relationship between fasting
blood glucose and Hb A(1c) in C57BL/6J, DBA/2J, and KK/HlJ mice with and without
diabetes mellitus. Daily averaged
blood glucose levels based on continuous
glucose monitoring and effects of 6-h vs. overnight fasting on
blood glucose were determined. Daily averaged
blood glucose levels were highly correlated with Hb A(1c), as determined with a hand-held automated device using an immunodetection method. R(2) values were 0.90, 0.95, and 0.99 in KK/HIJ, C57BL/6J, and DBA/2J, respectively. Six-hour fasting
blood glucose correlated more closely with the level of daily averaged
blood glucose and with Hb A(1c) than did
blood glucose following an overnight fast. To validate the immunoassay-determined Hb A(1c), we also measured total
glycosylated hemoglobin using boronate HPLC. Hb A(1c) values correlated well with total
glycosylated hemoglobin in all three strains but were relatively lower than total
glycosylated hemoglobin in diabetic DBA/2J mice. These results show that 6-h fasting
glucose provides a superior index of
glycemic control and correlates more closely with Hb A(1c) than overnight-fasted
blood glucose in these strains of mice.