Effect of Different Obesogenic Diets on Pancreatic Histology in Ossabaw Miniature Swine

Objective: Obesity is a factor in the outcome and severity of pancreatic conditions. We examined the effect of hypercaloric diets on the pancreata of Ossabaw swine, a large animal model of metabolic syndrome and obesity. Methods: Swine were fed with 1 of 4 diets: high-fructose (n = 9), atherogenic (n = 10), modified atherogenic (n = 6), or eucaloric standard diet (n = 12) for 24 weeks. Serum chemistries were measured, and pancreata were examined for histological abnormalities including steatosis, inflammation or fibrosis, insulin content, and oxidative stress. Results: The fructose, atherogenic, and modified atherogenic diet groups exhibited obesity, metabolic syndrome, islet enlargement, and significantly increased pancreatic steatosis (22.9% +/- 7.5%, 19.7% +/- 7.7%, and 38.7% +/- 15.3% fat in total tissue area, respectively) compared with controls (9.3% +/- 1.9%; P < 0.05). The modified atherogenic diet group showed significantly increased oxidative stress levels as evidenced by elevated serum malondialdehyde (3.0 +/- 3.3 vs 1.5 +/- 0.3 mu mol/L in controls; P = 0.006) and pancreatic malondialdehyde (0.1 +/- 0.12 vs 0.04 +/- 0.01 nmol/mg protein in controls; P=0.01). None of the swine exhibited pancreatitis or cellular injury. Conclusions: Ossabaw swine fed with a modified atherogenic diet developed significant pancreatic steatosis and increased oxidative stress, but no other histological abnormalities were observed.