Changes in stone composition over two decades: evaluation of over 10,000 stone analyses

Abstract

To examine the changes in stone composition from 1990 to 2010. A retrospective review was performed of all renal and ureteral stones submitted from the state of Massachusetts to a single laboratory (Laboratory for Stone Research, Newton, MA) for the years 1990 and 2010. Stone composition was determined by infrared spectroscopy and/or polarizing microscopy. A total of 11,099 stones were evaluated (56.7% from 1990, 43.3% from 2010). From 1990 to 2010, the percentage of stones from females (i.e., female/male ratio) increased significantly (29.8% in 1990 to 39.1% in 2010, p < 0.001). Among women, from 1990 to 2010, there was a significant increase in stones which were >50% uric acid (7.6-10.2%, p < 0.005) and a significant decrease in struvite stones (7.8-3.0%, p < 0.001). Among women with calcium stones, the % apatite per stone decreased significantly (20.0 vs. 11.7%, p < 0.001). Among men, there were no changes in stones which were majority uric acid (11.7-10.8%, p = 0.2). Among men with calcium stones, the % apatite per stone increased significantly (9.8 vs. 12.5%, p < 0.001). Males also demonstrated a significant increase in both cystine (0.1-0.6%, p < 0.001) and struvite stones (2.8-3.7%, p = 0.02). The epidemiology of stone disease continues to evolve and appears to vary according to gender. While some of these findings may be related to population changes in body mass index and obesity, the etiology of others remains unclear.

The New Epidemiology of Nephrolithiasis

“…Among those with calcium stones, the proportion of hydroxyapatite per stone increased significantly in men (8.7% to 11.4%), whereas it decreased in women (19.7% to 11.7%). 20 GEOGRAPHY AND TEMPERATURE It has been recognized for some time that there appears to be a "stone belt" in the Southern United States. One of the earlier studies characterizing this geographical distribution used the second Cancer Prevention Study that surveyed 1,185,124 men and women regarding kidney stone history.…”

Effect of citrus-based products on urine profile: A systematic review and meta-analysis

“…Calcium-based urinary tract stone is the most common stone composition found in urolithiasis 9, 10 . Supersaturation is believed to be the mechanism behind calcium stone formation 11 .…”

Temporal Changes in Kidney Stone Composition and in Risk Factors Predisposing to Stone Formation

“…A recent study by Moses et al also confirmed the narrowing gender gap by showing significant increase of female stone formers with >50% UA content 24 . Our results confirm the NHANES findings, with an increase in female CaSF proportion from 24% to 42% over time (Figure 1B), but differ from Moses et al’s findings, possibly due to the use of different stone analysis cutoff (70% vs. 50% 24 ) . Another study by Yang et al from China indicated that the occurrence of uric acid stone decreased from 2002 to 2014 25 , while we observed the opposite.…”