Effects of glycerol on metabolism and hemodynamics: A pilot study

Abstract

The purpose of this study was to determine the effects of glycerol on glucose, total cholesterol, and triacylglycerol concentrations and on blood and plasma viscosity. Thirty-two healthy subjects who were selected randomly were given glycerol 5 mL orally; the study variables were then measured for 120 minutes using a capillary tube viscometer and clinical autoanalyzers. Maximum decreases from baseline were 5.18% at 30 minutes ( P < 0.001) for blood viscosity and 1.31% at 15 minutes ( P = 0.02) for plasma viscosity. Viscosity values decreased throughout the study; at 120 minutes the decrease in blood viscosity (4.70%) was significant ( P < 0.001), whereas the decrease in plasma viscosity was not significant. Glucose and triacylglycerol concentrations remained elevated during the study; the largest increases from baseline were 11.93% at 30 minutes ( P < 0.01) for glucose and 92.24% at 30 minutes ( P < 0.001) for triacylglycerol whereas the increases at 120 minutes were 7.99% ( P = 0.002) and 11.39% ( P < 0.001), respectively. The maximum decrease in total cholesterol (3.64%) was measured at 15 minutes ( P < 0.01); the decrease at 120 minutes was 2.03% ( P < 0.001). Based on Poiseuille's hydrodynamics equation, when viscosity decreases 4.71%, the blood flow rate increases 4.94%. The equivalent of this physiologic compensatory change is a 4.94% reduction in blood pressure, which allows the initial flow rate to be maintained. Results of this study suggest that glycerol rapidly affects metabolism and hemodynamics and that glycerol may be shown to have a role in the associated control mechanisms.