Biosen glucose analyzer

All participants were enrolled in the Michigan Medicine Weight Management Program and were given an opportunity to opt in to the program’s research component, which was reviewed and approved by the Institutional Review Board of the University of Michigan and registered on ClinicalTrials.gov (NCT02043457). Patients with T2D were diagnosed based on the American Diabetes Association criteria for T2D (A1C ≥ 6.5; fasting blood glucose ≥ 126 mg/dL; or 2-hour blood glucose ≥ 200 mg/dL) or had been previously diagnosed with T2D and were taking glucose-lowering medications for T2D. MASLD was defined based on elevation of ALT and elevated ratio of ALT/AST (1.5×) in the absence of other causes of chronic liver disease. Plasma samples were obtained during an MMTT. After a 12-hour fast, 1 can of Ensure was consumed over 10 minutes along with the simultaneous administration of 650 mg of acetaminophen to estimate gut transit time by measuring serum acetaminophen levels. A catheter was placed in the antecubital vein, and 20 mL of blood was drawn (EDTA plasma tubes 3 × 5 mL and 5 mL serum for acetaminophen and glucose levels) at 0 and 60 minutes and 3 mL drawn at 15, 30, 60, 90, 120, 150, and 180 minutes. Plasma samples at 180 minutes were analyzed for blood glucose (Biosen Glucose Analyzer, EKF Diagnostics) and plasma FGF19 levels (R&D Systems).

Body weight was monitored biweekly. IPGTT was performed by intraperitoneal injection of 50% dextrose (2 g/kg) in 4-hour fasted mice. MMTT was performed via an oral gavage of liquid meal (volume 200 μL Ensure Plus spiked with a 40 mg dextrose and 4 mg acetaminophen, MilliporeSigma) in 4-hour fasted mice. Blood was obtained from the tail vein, and blood glucose was measured with Biosen Glucose Analyzer (EKF Diagnostics). Blood was collected at baseline and 15 minutes after gavage in EDTA-coated microtubes. Plasma acetaminophen levels were used to assess the rate of gastric emptying and were measured using spectrophotometry assay (Sekisui Diagnostics).

The device required an initial two-point calibration against two regular blood samples with a span in blood glucose of at least 11 mM. In the diabetic rats, this was obtained by collecting blood samples before and two hours after a sc. injection of human insulin (70 nmol/kg). During the experiment single-point calibrations were performed twice weekly by collecting a basal blood sample (10 μl) from the tail vein in the morning before dosing. The blood glucose levels were evaluated using a Biosen glucose analyzer (EKF Diagnostics, Barleben, Germany).