Composition of renal stones and their frequency in a stone clinic: Relationship to parameters of mineral metabolism in serum and urine

Abstract

Stone analyses (kidney, upper urinary tract) of the department of Urology, University of Erlangen, from a four-year-period (1974-1977) have been recorded with emphasis to stone composition, sex and age of the pertinent stone forming patients. During this time period there were no substantial changes as regards the per cent frequency of the various stone types. The most frequent type was calcium oxalate (CaOx), followed by uric acid, calcium phosphate (CaP), struvite and cystine. Stone analyses were mostly requested for patients between 46 and 55 years of age. Stone incidence in our clinic is calculated to be 1.22 times higher in males than females, especially beyond 36 years of age. The frequency peaks are: pure (= 100 per cent) CaOx 36-45 years; CaOx with additional mineral phases (mostly CaP) 46-55 years; uric acid 56-65 years; CaP 26-35 years. From those patients who underwent further investigations in searching for metabolic abnormalities serum concentrations, urine mineral clearances in fasting urine samples, and activity products of stone forming mineral phases in sequentially collected specimens from 24 h and 2 h fasting urine had been measured and compared with values from healthy control subjects. In urolithiasis (idiopathic) there is a normal parathyroid hormone blood level, a generally lower serum inorganic phosphate and magnesium concentration. In pure (= 100 per cent) CaOx and uric acid lithiasis serum uric acid and creatinine are higher than in controls, urine pH and calcium clearance in some groups are different too. Clearances of magnesium, uric acid, phosphate, sodium are within normal limits in urolithiasis. When expressing the propensity to form stones in terms of activity products, then only uric acid lithiasis deviates substantially from normal. All other stone types differ only slightly or not at all from each other and controls respectively. It is concluded that 1) in our geographic region the various stone types prevail in different age periods; 2) there are distinct alterations of parameters of mineral metabolism in urolithiasis; 3) measuring urine clearances may lead to assume falsely normal mean urine excretion of stone forming constituents.

Fourier transform infrared spectroscopy for analysis of kidney stones

“…This cross-sectional study also provided important information on the pattern of urolithiasis in a developing country. In the present study, the gender distribution was comparable with previous international and local data and showed a male preponderance of urolithiasis (male:female ratio, 4.6:1) [ 14 15 16 17 18 ]. Most of the stones from this study were of the mixed variety with more COM and uric acid content ( Table 3 ).…”

Evaluation of biochemical parameters in calcium oxalate renal stone formers

“…The selected individuals were not on any type of vitamin or minerals and apparently to be of no significant differences in consuming red meat and carbonated or soda beverages, which have been reported to exert their effects by changing urinary parameters (13,14) The present study also showed a significant decrease in serum uric acid in calcium oxalate stone formers, group B when compared to healthy control (p=0.015) (table 2), this decrease has been observed by Scholz et al study 16 and Gyawali et al study 17 which may be related to a decrease in antioxidant activity in stone formers. 18 However, Gyawali et al study explained the result by multifactorial etiology of urinary stone and some genetic variation in Nepalese patients.…”

An in Situ Atomic Force Microscopy Study of Uric Acid Crystal Growth

“…Two large-scale studies in the U. S. indicated that the percentage of stones containing uric acid as a primary constituent increased from 8.6% 3 to 16.5% 4 between 1962 and 1989, nearly doubling over a 27-year period. Comparable studies in other developed nations show that the prevalence of uric acid stones varies considerably, [5][6][7][8][9][10][11][12] ranging from a low of 4% in Sweden to a high of 39.5% in Israel. The pathogenic deposition of any crystalline species in vivo can be regarded, in essence, as a response to a solubility problem.…”