Fructose tolerance test in obese people with and without type 2 diabetes

Al-Ozairi E, Rivard CJ, Sanchez Gonzalez LG, et al.

J Diabetes. 2019; 1– 8.

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  • To examine the acute effects of an oral fructose tolerance test (OFTT) on serum uric acid concentrations in people with metabolic syndrome and type 2 diabetes. The effects of an oral glucose tolerance test (OGTT) on serum uric acid concentrations in people with type 2 diabetes was also evaluated.


  • Fructose is distinct among common sugars in its ability to raise serum uric acid.
  • Some studies suggest fructose-induced uric acid production may have a role in the ability of this sugar to induce metabolic syndrome.
  • A fructose tolerance test has been developed previously to evaluate the relative ability of fructose to raise uric acid in individuals. However, the effect of fructose to raise uric acid in people with diabetes has not been studied.


  • A total of 275 participants, 143 with type-2 diabetes and 132 without, were recruited randomly through the Dasman Diabetes Institute (DDI) in Kuwait City. Both groups were matched for age and body mass index (BMI).
  • Anthropometric measurements were taken and, following an overnight fast, an OFTT was conducted.  Serum samples were collected at 60 minutes and 120 minutes for testing of serum uric acid and other laboratory parameters including glucose, very low-, low- and high-density lipoprotein cholesterol.
  • On a separate day, following an overnight fast, baseline blood glucose, uric acid level, and other laboratory parameters were examined.  Oral hypoglycemic agents and insulin were held that day, and an OGTT was conducted.


  • Serum uric acid was lower in people with type 2 diabetes compared to controls with a similar BMI, especially those with poor glucose control (glycosylated hemoglobin [HbA1c] ≥ 8%).
  • Fructose administration raised serum uric acid in both groups, with a lower absolute rise in people with diabetes.
  • People with diabetes with a blunted rise in serum uric acid had higher baseline serum uric acid concentrations and a higher BMI. People without diabetes with a higher BMI also showed a blunted serum uric acid response.
  • Oral glucose administration lowered serum uric acid in both participants, with a greater fall in those with diabetes.


  • The researchers concluded that both people with type 2 diabetes and obesity show a blunted rise in serum uric acid concentration in response to a fructose challenge despite evidence that fructose may be undergoing enhanced metabolism in these conditions.
  • Further research on the long-term relationship of glucose and fructose ingestion with uric acid metabolism in type 2 diabetes is needed.