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

Area of Science:

• Nephrology
• Urology
• Metabolic Disorders

Background:

• Global prevalence of kidney stones has risen significantly in recent decades.
• Limited research exists on temporal shifts in kidney stone formation risk and stone types.
• Understanding these trends is crucial for public health and clinical management.

Purpose of the Study:

• To investigate temporal changes in kidney stone composition.
• To analyze demographic, serum, and urinary parameters in kidney stone formers from 1980 to 2015.
• To identify factors influencing the increasing prevalence of different stone types.

Main Methods:

• Retrospective analysis of 1,516 patients with calcium or uric acid stones.
• Data collected from initial visits to a university kidney stone clinic between 1980 and 2015.
• Statistical analysis of demographic, biochemical, and urinary parameters over time.

Main Results:

• The proportion of uric acid stones increased from 7% to 14% between 1980 and 2015.
• Uric acid stone formers were older, had higher BMI, and lower urinary pH compared to calcium stone formers.
• Urinary pH emerged as the strongest clinical discriminant between uric acid and calcium stones.

Conclusions:

• A significant increase in uric acid stones was observed from 1980 to 2015.
• The proportion of female calcium stone formers increased over time, but not for uric acid stones.
• Urinary pH is the primary differentiating factor between uric acid and calcium stones.