Freestyle optium neo blood glucose and ketone monitoring system

At follow-up, biweekly body weight measures, fasting blood glucose levels at 5th and 8th month, and changes in the animals’ appearance or behavior were monitored closely. Whole blood glucose level was measured using a hand-held whole-blood glucose monitor (FreeStyle Optium Neo Blood Glucose and Ketone Monitoring System, sponsored by Abbott Diabetes Care) after 6 h of fasting period. Blood samples (5 μl or less) were taken from tail tip after needle punctuation. Sex and species specific reference ranges were used to define abnormal levels (Ayala et al., 2010 (link); Benede-Ubieto et al., 2020 (link)). Lifespan of each animal were recorded individually. The autopsy of the animals resulting in spontaneous mortality was performed and macroscopically observed pathological changes were recorded. Additionally, three animals from each group were sacrificed at about 18 months and liver tissues evaluated by histological methods.

Four-month-old mice were fasted for 6 hours, and blood glucose concentration was measured at 0, 30, 60, 90, 120, and 180 minutes following an IP injection of glucose (2 g/kg, Sigma) or insulin (0.75 unit/kg, Sigma). Blood samples from nonfasted and 6-hour-fasted mice were collected for beta-hydroxybutyrate measurements. The concentrations of blood glucose and beta-hydroxybutyrate were measured using FreeStyle Optium Neo Blood Glucose and Ketone Monitoring System (Abbott Diabetes Care).