Dietary consumption of saturated fats and simple sugars exacerbates systolic and diastolic dysfunction and abnormal LV remodeling in diabetic rats

The incidence of obesity, type 2 diabetes and cardiovascular disease is increasing in part due to increased consumption of saturated fat and simple sugars. We evaluated the effect of diets high in fat and/or carbohydrate on left ventricular (LV) morphology and function with or without diabetes. Young male rats received control (CON; 12% kcal fat/19% protein/69% carbohydrate), moderate fat and carbohydrate (MFC; 40/15/45%) or high fat (HF; 60/19/21%) diets; LV morphology and function were evaluated at 2 and 14wk. Blood glucose was unchanged at 2wk; however, at 14 wk glucose in MFC was 2-fold higher (p<0.05) than HF or CON. Cardiac function was not different between groups at either time. In a second study after 2wk of dietary intervention, animals received 2x35mg/kg streptozotocin (STZ) injections i.p. 24h apart. The response to STZ was enhanced in MFC compared to CON and HF. 12wk after STZ LV systolic dysfunction was evident in MFC and HF compared to CON with lower velocity of circumferential shortening in MFC and HF and higher systolic wall stress in MFC. MFC but not HF exhibited diastolic dysfunction with decreased chamber stiffness and an eccentric LV hypertrophy. In summary, consumption of diets high in fat and/or carbohydrate do not alter cardiac function in young animals; however, in the presence of diabetes, there is systolic and diastolic dysfunction and abnormal LV remodeling that may be exaggerated in MFC.