Investigation of the biomechanical properties of the aorta in diabetic glycaemic variability rats

Despite substantial advancements in comprehending the mechanisms underlying arterial vascular damage induced by diabetes, the vascular biomechanical properties influenced by glycemic variability during these processes remain largely elusive. Spontaneous type 2 diabetes mellitus Go-to-Kakizaki (GK) rats were subjected to an eight-week high-fat diet, while glucose and insulin injections were administered at staggered peaks to simulate the glycemic variability model of diabetes. The mechanical properties of the abdominal aortas were evaluated through uniaxial mechanical tensile tests. Subsequently, metabolism-related indicators including fasting blood glucose (FBG), fasting insulin (FINS), insulin resistance index (HOMA-IR), serum biochemical parameters, glucose tolerance test (GTT), and insulin tolerance test (ITT) were assessed to evaluate glucose metabolism and insulin sensitivity. Finally, histological analysis was conducted to assess aortic and renal injury. Diabetic glycemic variability impaired the mechanical properties of blood vessels by exhibiting brittle failure characteristics through decreased tensile strength and attenuated tensile modulus of the aorta. Additionally, diabetic glycemic variability significantly increased susceptibility to develop hyperglycemia, insulin resistance, and lipid metabolism disorders in GK rats fed a high-fat diet. Abnormal fluctuations in blood glucose directly led to specific changes in renal microvessels before major arterial complications occurred.