Effects of Fructose Feeding on Blood Parameters and Blood Pressure in Impaired Glucose-tolerant Subjects

The effects of fructose and glucose on selected blood parameters and blood pressure after 4 weeks of oral ingestion were investigated in nine impaired glucose-tolerant subjects (IGTS) and nine normal glucose-tolerant subjects (NGTS). The criteria for IGTS were (1) 1- or 2-hour postprandial glucose levels between 160 and 200 mg/dL (8.8 to 11.1 mmol/L); (2) compliance with the diet; and (3) no cardiac or renal complication. The mean increment in the area under the plasma glucose and insulin curves after a glucose load was significantly greater following glucose than following fructose ingestion in both IGTS and NGTS (p less than .05). Glycosylated hemoglobin was greater after glucose than after fructose ingestion in IGTS and NGTS (71 gm/L vs. 61 gm/L in IGTS; 61 gm/L vs. 59 gm/L in NGTS). Serum triglyceride level in IGTS fed glucose was 173 mg/dL (1.90 mmol/L), whereas in those fed fructose, it was 154 mg/dL (1.69 mmol/L). Serum cholesterol was also greater after glucose than after fructose ingestion in all subjects. However, the differences were not statistically significant. Urate, pyruvate, and lactate levels were significantly greater in IGTS fed glucose than in IGTS fed fructose. Systolic and diastolic pressures were lower in IGTS fed fructose than in IGTS fed glucose. The present study shows that a 4-week oral ingestion of moderate amounts of fructose appears to have more benefits than an equivalent glucose ingestion in both IGTS and NGTS. However, greater benefits were found in IGTS than in NGTS.