Brief report: Circadian variation in insulin response in African green monkeys (Cercopithecus aethiops)

Among a group of African green monkeys (Cercopithecus aethiops), plasma insulin concentrations were greater following either intravenous (IV) glucose infusion or oral feeding at 0800 compared with IV glucose or oral feeding at 1700. Glucose clearance rates after IV infusion were similar at the two test times. Insulin/glucose ratios were greater following either IV glucose infusion or oral feeding at 0800 compared with 1700. These circadian variations in plasma insulin response are similar to reports of human studies and suggest this nonhuman primate species may be an appropriate animal model for chronobiological metabolic studies.