Fructose increases risk for kidney stones: potential role in metabolic syndrome and heat stress

• Published in: BMC nephrology Vol. 19; no. 1; pp. 315 - 7
• Main Authors: Johnson, Richard J., Perez-Pozo, Santos E., Lillo, Julian Lopez, Grases, Felix, Schold, Jesse D., Kuwabara, Masanari, Sato, Yuka, Hernando, Ana Andres, Garcia, Gabriela, Jensen, Thomas, Rivard, Christopher, Sanchez-Lozada, Laura G., Roncal, Carlos, Lanaspa, Miguel A.
• Format: Journal Article
• Language: English
• Published: London BioMed Central 08.11.2018; BioMed Central Ltd; BMC
• Subjects: Adult; Aged; Calcium; Calcium Oxalate - urine; Calculi; Cardiovascular disease; Citric acid; Clinical Research; Diabetes; Fructose; Fructose - administration & dosage; Fructose - adverse effects; Heat stress; Heat-Shock Response - drug effects; Heat-Shock Response - physiology; Humans; Hypertension; Internal Medicine; Kidney Calculi - chemically induced; Kidney Calculi - epidemiology; Kidney Calculi - urine; Kidney diseases; Kidney stone; Kidney stones; Kidneys; Magnesium; Male; Medicine; Medicine & Public Health; Metabolic syndrome; Metabolic Syndrome - chemically induced; Metabolic Syndrome - epidemiology; Metabolic Syndrome - urine; Middle Aged; Nephrolithiasis; Nephrology; Obesity; Oxalic acid; Parathyroid hormone; pH effects; Phosphorus; Research Article; Risk Factors; Serum levels; Sodium; Sucrose; Sugar; Syrups; Uric acid; Uric Acid - urine; Urine; Vitamin D; United States > US; Sucrose; Oxalate; Citrate; Magnesium; Uric acid; Fructose; Sugar; Kidney stone
• ISSN: 1471-2369; 1471-2369
• DOI: 10.1186/s12882-018-1105-0

Background Fructose intake, mainly as table sugar or high fructose corn syrup, has increased in recent decades and is associated with increased risk for kidney stones. We hypothesized that fructose intake alters serum and urinary components involved in stone formation. Methods We analyzed a previously published randomized controlled study that included 33 healthy male adults (40–65 years of age) who ingested 200 g of fructose (supplied in a 2-L volume of 10% fructose in water) daily for 2 weeks. Participants were evaluated at the Unit of Nephrology of the Mateo Orfila Hospital in Menorca. Changes in serum levels of magnesium, calcium, uric acid, phosphorus, vitamin D, and intact PTH levels were evaluated. Urine magnesium, calcium, uric acid, phosphorus, citrate, oxalate, sodium, potassium, as well as urinary pH, were measured. Results Ingestion of fructose was associated with an increased serum level of uric acid ( p  < 0.001), a decrease in serum ionized calcium ( p  = 0.003) with a mild increase in PTH ( p  < 0.05) and a drop in urinary pH ( p  = 0.02), an increase in urine oxalate ( p  = 0.016) and decrease in urinary magnesium ( p  = 0.003). Conclusions Fructose appears to increase urinary stone formation in part via effects on urate metabolism and urinary pH, and also via effects on oxalate. Fructose may be a contributing factor for the development of kidney stones in subjects with metabolic syndrome and those suffering from heat stress. Trial registration ClinicalTrials.gov NCT00639756 March 20, 2008.