Effects of acute fructose loading on levels of serum uric acid-a pilot study

Background: Fructose intake may lead to hyperuricaemia, which is associated with increased risk and progression of kidney disease. We aimed to explore the acute effects of fructose loading from different sources, with and without a pizza, on levels of serum uric acid in patients with chronic kidney disease (CKD), type 2 diabetes (T2D) without CKD, and in healthy subjects (HS).

Methods: The study included six HS, and three CKD stage 4-5 and seven T2D patients. Drinks consumed were blueberry drink (17.5 g fructose), Coca-Cola (18 g fructose) and fructose drink (35 g fructose). The drinks were also combined with pizza, in total six interventions. Serum samples were collected fasting and 30, 60, 90 and 120 minutes after intake and also 240 minutes after drink + pizza, and analysed for fructose, uric acid and triglycerides. Postprandial responses were explored using repeated-measure ANOVA.

Results: Baseline serum uric acid levels were increased in CKD (P = 0.037). There were significant differences in serum fructose and serum uric levels over time between drinks and drinks + pizza for all groups (P < 0.001 and P < 0.05, respectively). The highest peak in serum fructose followed the fructose drink interventions and the lowest the blueberry drink. The fructose drink interventions gave the highest responses in serum uric acid and the lowest responses followed the blueberry drink. Triglycerides increased following pizza interventions (P < 0.001).

Conclusions: Intake of fructose increases serum uric acid. The fructose intake via a blueberry drink induced lowest increase and thus may be protective.