Viscosity modulates blood glucose response to nutrient solutions in dogs

The relationship between postprandial blood glucose levels and meal viscosity was studied by adding various combinations of hydroxypropylmethylcellulose to glucose solutions and administering them to female mongrel dogs. Glucose was administered as 5% or 20% solutions in water. Hydroxypropyl-methylcellulose was dissolved in the glucose solutions to yield low (5000 cP measured at 37 degrees C and 1 s-1), medium (15,000 cP) or high (30,000 cP) viscosities. High viscosity hydroxypropylmethylcellulose significantly reduced the maximum blood glucose concentration, Cmax, by 60% (5% glucose meal) and 40% (20% glucose meal) while reducing the area under the blood level vs. time curve (AUC0-3 h) by 40-50%. Medium viscosity hydroxypropylmethylcellulose reduced the Cmax at both glucose levels, but reduced the AUC only for the 5% glucose meal. Low viscosity HPMC lowered the Cmax only after the 5% glucose meal, and had no significant effect on the AUC at either glucose level. The average time to reach maximum concentration, Tmax, was prolonged two- to three-fold at all viscosity levels for the 5% glucose solutions, but was not affected when 20% glucose solutions were administered. It was concluded that hydroxypropylmethylcellulose can effectively retard the absorption of glucose from the gastrointestinal tract, and that the extent of this effect is related to the viscosity of the solution administered.