Rethinking the role of urinary magnesium in calcium urolithiasis

Association of proton pump inhibitor use with risk of kidney stones: an analysis of cross-sectional data from the US National Health and Nutrition Examination Survey (2007-2018)

OBJECTIVE

Several studies have suggested a potential link between use of proton pump inhibitors (PPIs) and the risk of kidney stones, attributed to alterations in urine mineral levels. Our study aimed to investigate the association between PPI use and kidney stones in US adults.

DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey (2007-2018).

PARTICIPANTS

27 075 individuals with complete information on PPI use and history of kidney stones were included in this study.

OUTCOMES AND ANALYSES

Non-linear analysis, logistic regression analysis and subgroup analysis were conducted to estimate the relationship between PPI use and the occurrence and recurrence of kidney stones, after adjusting for potential confounding factors.

RESULTS

Multivariable logistic regression analysis revealed a significant association between PPI use and kidney stones (OR 1.31, 95% CI 1.07 to 1.60), with a 4% increase in the prevalence of kidney stones for each additional year of PPI use (p<0.001). Similarly, PPI use was significantly associated with recurrent kidney stones (OR 1.49, 95% CI 1.04 to 2.13), with a 7% increase in the recurrence of kidney stones for each additional year of PPI use (p<0.001). Furthermore, these associations remained significant even after conducting propensity score matching analysis on a subset of PPI users and non-users (all p≤0.001). Subgroup analyses showed that the effects of PPI use on kidney stones differed by age, sex, race and body mass index.

CONCLUSIONS

This study indicated that long-term use of PPI was associated with a higher risk of both the presence and recurrence of kidney stones.

Association between Urolithiasis and History Proton Pump Inhibitor Medication: A Nested Case-Control Study

A few retrospective studies have suggested the risk of urolithiasis associated with the use of proton pump inhibitors (PPIs). The current research intended to estimate the risk of urolithiasis according to previous PPI use. A nested case-control study was conducted using the National Health Insurance Service-National Health Screening Cohort in Korea. A total of 28,962 patients with urolithiasis and 115,848 control participants were selected. The previous prescription history of PPI with days of PPI prescription was collected. To calculate the odds ratios (OR) of past, current, and days of PPI use for urolithiasis, logistic regression models were used. Subgroup analyses were conducted. The urolithiasis group demonstrated a higher rate of current PPI users than the control group (60.9% vs. 43.7%). The current PPI users indicated 2.49 times higher odds for urolithiasis than no PPI users (95% confidence intervals [CI] = 2.33−2.66). A longer duration of PPI use was associated with greater odds for urolithiasis (adjusted OR = 1.65 (95% CI = 1.54−1.77) < 1.97 (95% CI = 1.84−2.11) < 2.32 (95% CI = 2.14−2.49) for 1−19 days, 30−364 days, and 365 or more days of PPI prescription). All subgroup analyses described a consistently positive association of previous PPI use with urolithiasis. Prior PPI use was related to a higher risk of urolithiasis. The relationship between previous PPI use and urolithiasis demonstrated a dose-response association.

Proton pump inhibitors use and risk of incident nephrolithiasis

Proton pump inhibitors (PPIs) are widely prescribed medications that have effects on both enteric and urinary solute handling with an unknown effect on risk of nephrolithiasis. Our objectives were to examine the association between PPI exposure and incident nephrolithiasis and to determine its effect on 24H urine chemistry. We performed a single-center retrospective study on patients diagnosed with gastroesophageal reflux disease (GERD) without a history of kidney stones. Exposure to PPIs was abstracted, and then subsequent kidney stone diagnoses were identified. Multivariable Cox models with time-varying covariates were used to estimate the hazard of PPI use on incident nephrolithiasis. We used multivariable linear regression to analyze a subset of patients who went through 24-h urine analysis. We identified n = 55,765 PPI-naïve GERD patients without prior kidney stone diagnoses of whom 40,866 (73.2%) were exposed to PPI over a median of 3 year follow up. On multivariable analysis, PPI use was associated with higher risk of incident kidney stone diagnoses (HR 1.19, 95% CI 1.06-1.34). Among 593 patients with GERD with 24-H urine data, the PPI-exposed group (n = 307) had significantly lower mean urinary citrate (mean 3.0 vs 3.4 mmol, p = 0.029) and urinary magnesium (mean 3.6 vs 4.3 mmol, p < 0.001) on multivariable analyses. Exposure to PPIs is associated with an increased risk of kidney stones among patients with GERD. Hypomagnesemia and hypocitraturia associated with PPI exposure may contribute to kidney stone risk.

Hypomagnesuria is Associated With Nephrolithiasis in Patients With Asymptomatic Primary Hyperparathyroidism

CONTEXT

The pathogenesis of nephrolithiasis in primary hyperparathyroidism (PHPT) remains to be elucidated. The latest guidelines suggest parathyroidectomy in patients with asymptomatic PHPT with hypercalciuria (> 400 mg/d) and increased stone risk profile.

OBJECTIVE

The objective of this work is to evaluate the association of urinary stone risk factors and nephrolithiasis in patients with asymptomatic sporadic PHPT and its clinical relevance.

DESIGN

A total of 157 consecutive patients with sporadic asymptomatic PHPT were evaluated by measurement of serum and 24-hour urinary parameters and kidney ultrasound.

RESULTS

Urinary parameters were tested in the univariate analysis as continuous and categorical variables. Only hypercalciuria and hypomagnesuria were significantly associated with nephrolithiasis in the univariate and multivariate analysis adjusted for age, sex, body mass index, estimated glomerular filtration rate, parathyroid hormone, 25-hydroxyvitamin D, serum calcium, and urine volume (odds ratio, OR 2.14 [1.10-4.56]; P = .04; OR 3.06 [1.26-7.43]; P = .013, respectively). Hypomagnesuria remained associated with nephrolithiasis in the multivariate analysis (OR 6.09 [1.57-23.5], P = .009) even when the analysis was limited to patients without concomitant hypercalciuria. The urinary calcium/magnesium (Ca/Mg) ratio was also associated with nephrolithiasis (univariate OR 1.62 [1.27-2.08]; P = .001 and multivariate analysis OR 1.74 [1.25-2.42], P = .001). Hypomagnesuria and urinary Ca/Mg ratio had a better, but rather low, positive predictive value compared with hypercalciuria.

CONCLUSIONS

Hypomagnesuria and urinary Ca/Mg ratio are each associated with silent nephrolithiasis and have potential clinical utility as risk factors, besides hypercalciuria, for kidney stones in asymptomatic PHPT patients. The other urinary indices that have been commonly thought to be associated with kidney stones in PHPT are not supported by our results.

Evaluating the associations between urinary excretion of magnesium and that of other components in calcium stone-forming patients

PURPOSE

Magnesium plays numerous vital roles in human's body. It is known as a protective factor in stone formation by binding to oxalate in the intestinal and urinary system, and decreasing its absorption and crystallization, respectively. Due to controversies about the association between the 24-h urine magnesium and other urine metabolites in different studies, this study was designed to find a clear answer to this question.

METHODS

In this retrospective cross-sectional study, data from 24-h urinalysis of the calcium stone-forming (CSF) patients were assessed. The correlation between 24-h urine (24-U) magnesium to creatinine ratio (Mg/Cr) with other 24-U metabolites to creatinine ratio was assessed, using Spearman correlation test. The association between 24-U magnesium and 24-U oxalate was also studied in a multivariate logistic regression model.

RESULTS

Among 965 patients, the level of Mg/Cr showed a direct association with all other 24-U metabolite to Cr ratio (p-value < 0.001 for all analyses). The result of multivariate regression analysis showed that the higher quartile of 24-U oxalate (> 47 mg/24 h) increased the odds of 24-U magnesium more than 75 mg/24 h (data median) (OR 1.89, 95% CI 1.14-3.13) comparing with the lower quartile of 24-U oxalate (≤ 26 mg/24 h).

CONCLUSIONS

In a routine dietary habit, since rich sources of magnesium contain a high amount of oxalate at the same time, it is not surprising that magnesium level in 24-h urinalysis showed a direct association with 24-h urine oxalate.

Evaluating the effectiveness of adding magnesium chloride to conventional protocol of citrate alkali therapy on kidney stone size

BACKGROUND

Potassium citrate (K-Cit) is one of the therapeutic solutions broadly used in patients with urolithiasis. However, recent studies have shown that it is not so effective. Therefore, the goal of our study was to evaluate the effect of a combination of K-Cit - MgCl₂ oral supplements, on urinary stone size.

MATERIALS AND METHODS

This study was performed on 70 asymptomatic urolithiasis cases. The supplements included K-Cit and magnesium chloride (MgCl₂), purchased from (Merck Company, Germany). The patients were randomly divided into two groups. The urinary stone size was measured in the control group after prescribing K-Cit alone and the treated group with combination of K-Cit and MgCl₂ for 4 weeks by ultrasonography and also urinary parameter was measured in each groups.

RESULTS

The mean age of patients was 16.26 ± 5.70 years. Hyperoxaluria and hypercalciuria were seen in 70% and 52% of patients, respectively. Initially, the mean urinary stone size was measured in each groups and there is not any significant different. However, we find a significant decrease in urinary stone size in group which is treated with combination of K-Cit and MgCl₂ for 4 weeks in comparison with control group treated with K-Cit alone in the same duration of therapeutic course (5.1 ± 0.8 vs. 2.5 ± 1.2, P < 0.05). All ultrasonography were performed by one radiologist and device.

CONCLUSION

Our results suggested that a combination of K-Cit and MgCl₂ chloride is more effective on decreasing urinary stone size than K-Cit alone.

The elementome of calcium-based urinary stones and its role in urolithiasis

Urolithiasis affects around 10% of the US population with an increasing rate of prevalence, recurrence and penetrance. The causes for the formation of most urinary calculi remain poorly understood, but obtaining the chemical composition of these stones might help identify key aspects of this process and new targets for treatment. The majority of urinary stones are composed of calcium that is complexed in a crystalline matrix with organic and inorganic components. Surprisingly, mitigation of urolithiasis risk by altering calcium homeostasis has not been very effective. Thus, studies to identify other therapeutic stone-specific targets, using proteomics, metabolomics and microscopy techniques, have been conducted, revealing a high level of complexity. The data suggest that numerous metals other than calcium and many nonmetals are present within calculi at measurable levels and several have distinct distribution patterns. Manipulation of the levels of some of these elemental components of calcium-based stones has resulted in clinically beneficial changes in stone chemistry and rate of stone formation. The elementome--the full spectrum of elemental content--of calcium-based urinary calculi is emerging as a new concept in stone research that continues to provide important insights for improved understanding and prevention of urinary stone disease.

Evaluation of calcium and magnesium in scalp hair samples of population consuming different drinking water: risk of kidney stone

The objective of this study was to examine the relationship between calcium (Ca) and magnesium (Mg) in underground water (UGW), bottled mineral water (BMW), and domestic treated water (DTW) with related to risk of kidney stones. The water samples were collected from different areas of Sindh, Pakistan. The scalp hair samples of both genders, age ranged 30-60 years, consuming different types of water, have or have not kidney disorders, were selected. The Ca and Mg concentrations were determined in scalp hair of study subjects and water by flame atomic absorption spectroscopy. The Ca and Mg contents in different types of drinking water, UGW, DTW, and BMW, were found in the range of 79.1-466, 23.7-140, and 45-270 mg/L and 4.43-125, 5.23-39.6, and 7.16-51.3 mg/L, respectively. It was observed that Ca concentration in the scalp hair samples of kidney stone patients consuming different types of drinking water was found to be higher (2,895-4721 μg/g) while Mg level (84.3-101 μg/g) was lower as compare to referents subjects (2,490-2,730 μg/g for Ca, 107-128 μg/g for Mg) in both genders. The positive correlation was found between Ca and Mg levels in water with related to kidney stone formations in population, especially who consumed underground water. A relative risk and odd ratio were calculated; the relative risk had a strong positive association with incidence of kidney stone which depends on types of drinking water.

Influence of nutrition on feline calcium oxalate urolithiasis with emphasis on endogenous oxalate synthesis

The prevalence of calcium oxalate (CaOx) uroliths detected in cats with lower urinary tract disease has shown a sharp increase over the last decades with a concomitant reciprocal decrease in the occurrence of struvite (magnesium ammonium phosphate) uroliths. CaOx stone-preventative diets are available nowadays, but seem to be marginally effective, as CaOx urolith recurrence occurs in patients fed these diets. In order to improve the preventative measures against CaOx urolithiasis, it is important to understand its aetiopathogenesis. The main research focus in CaOx formation in cats has been on the role of Ca, whereas little research effort has been directed towards the role and origin of urinary oxalates. As in man, the exogenous origin of urinary oxalates in cats is thought to be of minor importance, although the precise contribution of dietary oxalates remains unclear. The generally accepted dietary risk factors for CaOx urolithiasis in cats are discussed and a model for the biosynthetic pathways of oxalate in feline liver is provided. Alanine:glyoxylate aminotransferase 1 (AGT1) in endogenous oxalate metabolism is a liver-specific enzyme targeted in the mitochondria in cats, and allows for efficient conversion of glyoxylate to glycine when fed a carnivorous diet. The low peroxisomal activity of AGT1 in cat liver is compatible with the view that felids utilised a low-carbohydrate diet throughout evolution. Future research should focus on understanding de novo biosynthesis of oxalate in cats and their adaptation(s) in oxalate metabolism, and on dietary oxalate intake and absorption by cats.

Importance of magnesium in absorption and excretion of oxalate

INTRODUCTION

Magnesium treatment for calcium oxalate urolithiasis is discussed controversially. The aim of this study was to investigate the influence of magnesium supplementation on the oxalate absorption.

MATERIALS AND METHODS

The [13C2]oxalate absorption test was always performed three times in 6 healthy volunteers under standardized conditions, with one 10-mmol magnesium supplement together with the labeled oxalate and with two 10-mmol magnesium supplements given in 12-hour intervals.

RESULTS

The mean intestinal oxalate absorption under standard conditions was 8.6 +/- 2.83%. The oxalate absorption with one 10-mmol magnesium supplement was 5.2 +/- 1.40% and with two supplements 5.5 +/- 1.62%. Both decreases were statistically significant relative to the standard test, however, not significantly different from each other.

CONCLUSIONS

The results show that magnesium administration decreases the oxalate absorption, when magnesium is taken together with oxalate. However, magnesium administration does not decrease the oxalate absorption, when magnesium and oxalate intake differ by 12 h.

Characteristics of nanobacteria and their possible role in stone formation

Kidney stone formation is a multifactorial disease in which the defence mechanisms and risk factors are imbalanced in favour of stone formation. We have proposed a novel infectious agent, mineral forming nanobacteria (NB), to be active nidi that attach to, invade and damage the urinary epithelium of collecting ducts and papilla forming the calcium phosphate center(s) found in most kidney stones. Stone formation may proceed in urine supersaturated with calcium phosphate, calcium oxalate and uric acid/urate under the influence of crystallization promoters and inhibitors. Our hypothesis underlines the role of active nidi: even supersaturated urine requires nidi for crystallization to appear.

Calcium nephrolithiasis: effect of water hardness on urinary electrolytes

OBJECTIVES

To analyze the impact of water hardness from public water supplies on calcium stone incidence and 24-hour urine chemistries in patients with known calcium urinary stone formation. Patients are frequently concerned that their public water supply may contribute to urinary stone disease. Investigators have documented an inverse relationship between water hardness and calcium lithogenesis. Others have found no such association.

METHODS

Patients who form calcium stones (n = 4833) were identified geographically by their zip code. Water hardness information from distinct geographic public water supplies was obtained, and patient 24-hour urine chemistries were evaluated. Drinking water hardness was divided into decile rankings on the basis of the public water supply information obtained from the Environmental Protection Agency. These data were compared with patient questionnaires and 24-hour urine chemistries. The calcium and magnesium levels in the drinking water were analyzed as independent variables.

RESULTS

The number of total lifetime stone episodes was similar between patients residing in areas with soft public water and hard public water. Patients consuming the softest water decile formed 3.4 lifetime stones and those who consumed the hardest water developed 3.0 lifetime stones (P = 0.0017). The 24-hour urine calcium, magnesium, and citrate levels increased directly with drinking water hardness, and no significant change was found in urinary oxalate, uric acid, pH, or volume.

CONCLUSIONS

The impact of water hardness on urinary stone formation remains unclear, despite a weak correlation between water hardness and urinary calcium, magnesium, and citrate excretion. Tap water, however, can change urinary electrolytes in patients who form calcium stones.