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Factors Associated With the Lower Prevalence of Nephrolithiasis in Children Compared With Adults
Felix Grases1, Adrian Rodriguez1, Antonia Costa-Bauza1
1Laboratory of Renal Lithiasis Research, University Institute of Health Sciences Research (IUNICS-IdISPa), University of Balearic Islands, Palma de Mallorca, Spain.
Insights
Children have a lower prevalence of kidney stones due to distinct urinary parameters. Healthy children exhibit lower calcium and higher magnesium levels compared to adults, potentially explaining reduced nephrolithiasis risk.
Area of Science:
- Pediatric Nephrology
- Urolithiasis Research
- Biochemistry
Background:
- Kidney stones (nephrolithiasis) are less common in children than adults.
- Understanding the underlying physiological differences is crucial for prevention and treatment.
Purpose of the Study:
- To investigate the urinary lithogenic parameters in healthy children and adults.
- To compare these parameters with those in pediatric and adult kidney stone formers.
- To identify factors contributing to the lower prevalence of kidney stones in children.
Main Methods:
- Comparative analysis of urinary lithogenic parameters.
- Inclusion of 75 healthy adults, 105 healthy children, and 3 groups of stone-forming patients (totaling 434 subjects).
- Measurement of 24-hour urine samples for solute concentrations and ratios.
Main Results:
- Significant differences in calcium, magnesium, and phosphorous concentrations between healthy children and adults.
- Children had a 2-fold lower calcium/creatinine ratio and a 2-fold higher magnesium/creatinine ratio than adults.
- Calcium oxalate dihydrate stone formers showed higher calcium/creatinine and lower citrate/creatinine ratios compared to healthy adults.
Conclusions:
- Urinary calcium and magnesium to creatinine ratios are key differentiating factors.
- Morphoanatomic factors and lifestyle habits likely contribute to lower pediatric nephrolithiasis rates.
- These findings provide insights into the physiological basis for reduced kidney stone incidence in children.
Objective:
To determine the reasons behind the lower prevalence of kidney stones in children by assessing urinary lithogenic parameters in healthy children, healthy adults, and 3 groups of stone-former patients.
Methods:
The study subjects included 75 healthy adults, 105 healthy children, 62 patients with previous calcium oxalate monohydrate papillary stones, 120 patients with previous calcium oxalate monohydrate unattached stones, and 248 patients with previous calcium oxalate dihydrate stones. Twenty-four-hour urine samples were collected, and the urinary lithogenic parameters were measured.
Results:
Calcium, magnesium, and phosphorous concentration differed significantly between healthy children and adults. Except citrate, all solute/creatinine ratios differed between healthy children and adults. However, these differences were much more important in the cases of calcium and magnesium. The calcium/creatinine ratio was 2-fold lower, whereas the magnesium/creatinine ratio was 2-fold higher, in healthy children than that in healthy adults (P <.001 each). The calcium/creatinine ratio was higher and the citrate/creatinine ratio lower in calcium oxalate dihydrate stone formers than that in healthy adults.
Conclusion:
Ratios of calcium and magnesium to creatinine, as well as morphoanatomic factors and lifestyle habits, may explain the lower prevalence of nephrolithiasis in children than those in adults.
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