Abstract
We have previously shown that an oral glucose load increased both calciuria and oxaluria
while the ingestion of fructose induced a rise in calciuria and a decrease in oxaluria.
This latter effect remains unclear and might be linked to the reduced intestinal oxalate
absorption subsequent to digestive intolerance in some subjects. Such a hypothesis
could be enlightened by the study of a parenteral fructose load. Therefore in 7 healthy
subjects, we compared the effects of fructose infusion (F) (15 min iv infusion at
0.185 mmol/kg BW/min) to a control glucose infusion (G) on urinary calcium and oxalate.
In this study, glycemia and insulinemia increased less after (F) than after (G) (respectively
+ 21% vs + 216%, p < 0.001 and +230% vs +402%, p < 0.05) and phosphatemia decreased
less after (F) than after (G) (-7% vs -14%, p < 0.05). Urinary calcium and oxalate
increased only after (F) (respectively +64%, p < 0.01 and + 60%, p < 0.05). Urinary
uric acid, another urolithiasis factor, increased after both (F) and (G) (respectively
+45%; p < 0.01 and +42%; p < 0.01) but uricemia increased only after (F) (+25%; p
< 0.01). Our results suggest an additional reason to avoid the use of fructose in
parenteral nutrition, particularly in individuals with a known history of either calcium
oxalate or urate urolithiasis.
Key words
Calcium - Oxalate - Urate - Fructose Infusion - Urolithiasis
