High-fructose feeding elicits insulin resistance without hypertension in normal mongrel dogs

This study was undertaken to characterize blood pressure (by continuous blood pressure recording), renal hemodynamics, and excretory function in high-fructose-fed insulin-resistant dogs. We fed 10 mongrel dogs for 28 days with a normal sodium diet containing 60% of the calories either as fructose (n = 6) or dextrose (n = 4). Fructose-fed dogs developed insulin resistance by the 21st day of the experimental diet, as estimated by the mean glucose concentrations (in arbitrary units, AU) during the final hour of the insulin suppression test (640.3 +/- 57 AU fructose-fed dogs upsilon 397.5 +/- 24.7 AU dextrose fed dogs; P < .05). Neither of the groups showed any change in body weight, or in fasting plasma levels of glucose or insulin. There was no difference in mean arterial pressure between the groups before or during either diet, nor did we find any important alterations in renal function in these animals. We conclude that insulin resistance can be induced by a high-fructose diet in the dog. However, it is not accompanied by either hypertension or alteration in renal function. These findings emphasize the importance of continuously recording blood pressure under resting conditions and suggests that in the fructose-fed dog, insulin resistance does not appear to lead directly to hypertension.