The Impact of Sugars on Kidney Stone Formation

Various studies have found a trend connecting diabetes mellitus or carbohydrate malabsorption syndromes to kidney stone formation. However, the underlying mechanism causing this impact is unclear. This study aimed to investigate whether some of this correlation is due to the underlying chemistry of sugars as crystal growth modifiers. Thus, the impact of major dietary monosaccharides (glucose, fructose, and galactose) and disaccharides (lactose and sucrose) on the formation of calcium oxalate was investigated from a crystallization perspective. The nucleation rate of calcium oxalate generally showed a promotion when monosaccharides were present. An analysis of the crystals with Raman spectroscopy found that signals for the monosaccharides are present within the crystal, showing an association between the sugars and calcium oxalate. When lactose was present, there was an obvious promotion of nucleation. When sucrose was present, an interaction with both the crystal and the solution ions was observed. The presence of galactose had the most influence on the zeta potential of calcium oxalate when zinc ions were present, resulting in the smallest zeta potential value. These results suggest that the sugars in urine may promote calcium oxalate formation and agglomeration, and this may suggest a chemical connection to the higher prevalence of stones in diabetic patients.