Serum Free Fatty Acid and Triglyceride Levels Before and After Intravenous Fructose Infusion in Obese Subjects with Fatty Liver

Abstract

Effects of intravenous infusion of fructose (0.5g/kg. BW/hr for 2 hrs.) upon the serum triglyceride and free fatty acid levels were examined in 9 normal and 8 obese subjects with fatty livers.
The fasting serum triglyceride level of obese subjects (190.1±18.3mg/dl) was significantly higher than that of normal subjects (104.0±7.9mg/d/)(p<0.001). After fructose infusion, normal subjects showed the maximal decrement of the serum triglyceride level at 90 min and did not return to the initial value even at 240 min. While the serum triglyceride level of obese subjects showed a nadir at 60 min and then rose above initial value at 180 and 240 min, the increment of the serum triglyceride above the initial value was higher in obese subjects than in normal subjects at 180 (p<0.05) and 240 min (p<0.02).
The fasting serum free fatty acid level of obese subjects (1222.9±113.8 pEq/L) was significantly higher than that of normal subjects (687.1±102.9μEq/L)(p<0.01). The absolute decrement of serum free fatty acid above the initial value after fructose infusion was cbout the same in both groups, and the nadir of the serum free fatty acid level occurred at 120 min in both groups.
No significant alterations in blood glucose and plasma IRI level were observed in both groups during the 4 hrs after intravenous fructose load. The results suggested that:(1) insulin did not play an important role in lowering serum free fatty acid and triglyceride levels by intravenous fructose administration in normal and obese subjects, and (2) in obese subjects with fatty liver the intravenous fructose infusion induced more triglyceride release from the liver than from in normal subjects atalate astage. J. Japan Diab. Soc. 19 (1) 1976.