Introduction: Metabolic surgery has become an accepted option for the treatment of obesity and associated metabolic diseases like hypertension and type 2 diabetes. Adipose tissue dysfunction and ectopic storage of excess lipids are thought to be involved in the underlying pathophysiological process.
Objectives: The present study aims to clarify the effect of sleeve gastrectomy (SG) on adipose tissue microvasculature and health in an animal model of adipose type 2 diabetes.
Methods: After weaning, diabetic Goto-Kakizaki rats were either fed on standard rat chow or high-calorie diet. At 4 months, animals on high-calorie diet were randomized to SG, sham surgery, or control group. Non-diabetic Wistar rats served as further controls. At 6 months, glucose and lipid metabolisms were studied in vivo. After sacrifice, periepididymal adipose tissue was collected for histology and analysis of parameters of adipose tissue metabolism and insulin sensitivity.
Results: SG decreased body and adipose tissue weight and improved glycemic and lipid profiles. Fasting glycemia, area under the curve after intraperitoneal insulin tolerance test, and insulin resistance were decreased in operated animals. SG also reduced circulating triglycerides and cholesterol while increasing serum adiponectin and adipose tissue peroxisome proliferator-activated receptor γ (PPAR-γ) and perilipin A. Additionally, surgery improved adipose tissue vascular function and markedly increased vascular endothelial growth factor, cluster of differentiation 31, and endothelial nitric oxide synthase.
Conclusions: In our obese animal model of type 2 diabetes, SG significantly improved adipose tissue health and angiogenesis while reducing insulin resistance, involving PPAR-γ and markers of sprouting angiogenesis and endothelial function.
Keywords: Adipose tissue; Angiogenesis; Animal model; Sleeve gastrectomy; Type 2 diabetes.