Role of glycated proteins in detecting and monitoring diabetes in cynomolgus monkeys.

The use of glycated serum protein testing, as measured by serum fructosamine, to detect and monitor the diabetic state in 363 cynomolgus monkeys (Macaca fascicularis) consuming either standard diet or atherogenic diet was evaluated. Reference ranges were also established in 142 rhesus monkeys (M. mulatta) and 55 stumptail monkeys (M. arctoides). Values for serum fructosamine in all species ranged from approximately 0.5 to 2 mMol/liter. After determining the colony mean for each species and diet group, four cynomolgus monkeys were found to have serum fructosamine levels more than two standard deviations above the mean, whereas all values were normal in the rhesus and stumptail monkey colonies. These four animals were determined to be diabetic by repeated fasting glucose determinations and intravenous glucose tolerance testing. Serum fructosamine values correlated significantly with glycated hemoglobin (r = 0.61, P < 0.001) and fasting blood glucose (r = 0.70, P < 0.001) determinations in all diabetic and nondiabetic monkeys. The usefulness of serum fructosamine testing to monitor longitudinal glycemic control was also evaluated. Fasting blood glucose and fructosamine values for five previously diagnosed diabetic and five nondiabetic monkeys determined at 2-week intervals over a 20-week period correlated significantly (r = 0.75, P < 0.001). In conclusion, serum fructosamine may provide an objective parameter of antecedent glycemic control in nonhuman primates.