Search Results (22)

Acid–base balance is critical to human health and can be significantly influenced by dietary choices. The Western diet, characterized by high meat and cheese consumption, induces excess acidity, highlighting the need for strategies to mitigate this. Recent studies have focused on bicarbonate-rich mineral water as a viable solution. In this context, the present narrative review synthesizes the findings from recent scientific studies on bicarbonate-rich mineral water, specifically those with bicarbonate levels over 1300 mg/L and medium or low PRAL values. This water has been shown to exert beneficial effects on both urinary and blood parameters. The key effects include an increase in the urine pH and a profound reduction in net acid excretion as a sign for a reduced acid load. Additionally, bicarbonate mineral water has been shown to decrease the excretion of nephrolithiasis-related constituents, including calcium and oxalates, as well as inhibitory substances such as magnesium and citrates. In blood, bicarbonate-rich water has been demonstrated to stabilize pH and increase bicarbonate levels, thereby enhancing systemic buffering capacity. Clinically, these changes have been associated with a lowered risk of calcium oxalate stone formation and improved kidney health. Furthermore, bicarbonate-rich water has been shown to support bone health by reducing bone resorption markers. Consequently, the integration of bicarbonate-rich mineral water into the diet has the potential to enhance urinary and blood parameters, mitigate the risk of kidney stones, and strengthen skeletal integrity, thereby serving as a promising strategy for health promotion and disease prevention. While promising, these findings underscore the need for further research to establish long-term recommendations. Future interventional studies should be designed with rigorous randomization, larger sample sizes, cross-over methodologies, and comprehensive dietary assessments to address the methodological limitations of previous research. Full article

Background: Different types of kidney stones are associated with distinct changes in urine chemistry. Methods: We assessed urinary parameters of 98 patients with calcium oxalate (CaOx) stones one month following endoscopic stone removal. The 24 h urine analysis encompassed the assessment of various parameters, including volume, sodium, chloride, sulfate, nitrate, fluoride, phosphate, calcium, potassium, magnesium, oxalate, uric acid, citrate, creatinine, and pH levels. Results: Hypocitraturia was the most prevalent urinary abnormality (61.2%, n = 63), followed by low urine volume (53%, n = 52) and hypercalciuria (50%, n = 49). We did not find any statistically significant differences between patients with whewellite (COM) (n = 69) and weddellite (COD) stones (n = 29) (p > 0.05). However, oxalate concentration was the only parameter with a statistically significant intergroup difference (p = 0.0297). Additionally, in univariate linear regression analysis, urinary phosphate levels ≥ 48.0 mmol/d showed a trend towards significance (OR 0.17, 95% CI 0.02–1.15, p = 0.0692), indicating that phosphaturia is associated with a significant increase in the odds ratio of COD stones. To further explore metabolic heterogeneity among stone formers, we conducted cluster analysis, which revealed three distinct metabolic subgroups. Cluster 1 was predominantly associated with COM stones (80.5%) and exhibited significantly higher urinary excretion of sodium, calcium, oxalate, phosphate, and uric acid compared to Cluster 2, which had a more balanced distribution of monohydrate and dihydrate stones. Conclusions: These findings suggest that a specific metabolic phenotype may be linked to COM stone formation, providing a framework for risk stratification and personalized prevention strategies in calcium oxalate stone formers. Full article

Background and Objectives: Several micro- and macro-nutrient malnutrition states that are routinely assessed during clinical care of women in the antenatal period have been proposed as risk factors for preeclampsia. However, there is a paucity of data on the potential use of these biomarkers for detection of preeclampsia. The aim of this case-control study was to investigate the association of biomarkers from routine clinical tests, and those specific to micro- and macro-nutrient malnutrition, with the risk of preeclampsia. Materials and Methods: Venous blood samples of 250 participants with preeclampsia and 150 pregnant women without preeclampsia were collected and assayed immediately for the full blood count, urea and electrolytes, high-density cholesterol (HDL), total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL), oxidized low-density lipoprotein cholesterol (OxLDL), and selenium, in addition to urine iodine concentration (UIC). Results: The serum potassium/magnesium ratio (K⁺/Mg²⁺), UIC, fasting plasma glucose (FPG), thyroid stimulating hormone (TSH), lymphocyte percentage (L/WBC%), and the oxidized LDL/albumin ratio (OxLDL/Alb) were identified as independent predictors of preeclampsia. Conclusions: Serum potassium/magnesium ratio and other analytes essential for various biological processes, some of which are assayed during routine care, were significantly associated with preeclampsia, warranting further exploration as potential screening biomarkers in low-resource settings. Full article

Background: This cross-sectional study aimed to assess growth, body weight, and bone mineralization and to identify predictors of metabolic bone disease (MBD) in children with chronic intestinal failure (CIF) on long-term parenteral nutrition (LPN). Methods: Twenty-six children with CIF were evaluated on total parenteral nutrition (PN) for at least three years, and 60 healthy controls were assessed. Measurements included body weight, height, BMI, serum levels of 25-hydroxyvitamin D3 (25-OHD3), calcium (Ca), phosphorus (P), magnesium (Mg), and aluminum (Al), as well as urinary excretion of these elements. Dual-energy X-ray absorptiometry (DXA) and the mid-arm muscle area (MAMA) and mid-arm fat area (MAFA) of the CIF group were estimated. Results: CIF children had significantly lower height, weight, and BMI Z-scores than controls (p < 0.001). While the median bone mineral density (BMD) Z-score was >−2, 34.7% had L1–L4 Z-scores ≤ −2. Urinary Ca and Al excretion were higher in LPN patients, positively correlating with serum 25-OHD3 levels (r = 0.48). Lower serum Ca, P, and Mg were observed in LPN patients (p < 0.001), and BMC L1–L4 correlated positively with MAMA, MAFA, and BMI. Conclusions: The physical development of children who require long-term parenteral nutrition due to intestinal failure is poorer than that of healthy children. Although there are risk factors for bone mineralization disorders in children with intestinal failure, no clinical issues, such as pathological fractures, have been observed. Full article

This study investigated the risk profile and the impact of dietary intervention in calcium oxalate stone formers with enteric hyperoxaluria under controlled, standardized conditions. Thirty-seven patients were included in the study. Dietary and 24-h urinary parameters were obtained on the self-selected diet and a balanced, standardized diet. Tests for [¹³C₂]oxalate absorption, calcium- and ammonium chloride-loading were performed. Mean [¹³C₂]oxalate absorption was 18.8%. A significant positive association was observed between urinary oxalate excretion and intestinal oxalate absorption. In addition, urinary oxalate excretion was significantly correlated with dietary oxalate intake. Mean urinary oxalate excretion decreased from 0.841 mmol/24 h on the usual diet to 0.662 mmol/24 h on the balanced diet, corresponding to a reduction of 21.3%. Besides hyperoxaluria, hypocitraturia and hypomagnesuria were the most common urinary abnormalities at baseline, being present in 83.8% and 81.1% of patients, respectively. Urinary citrate increased by 50.9% and magnesium excretion increased by 25.2% on the balanced diet. As a result, the relative supersaturation of calcium oxalate declined significantly (by 36.2%) on the balanced diet. Since 41% of patients on the balanced diet still had a urine volume of less than 2.0 L/24 h, efforts should be made to increase urine volume by increasing fluid intake and reducing intestinal fluid losses. Dietary intervention proved to be effective in reducing urinary oxalate excretion and should be a cornerstone of the treatment of patients with enteric hyperoxaluria. Full article

Nephrolithiasis is a common urologic manifestation of Crohn’s disease. The purpose of this study was to investigate the clinical characteristics, intestinal oxalate absorption, and risk factors for urinary stone formation in these patients. In total, 27 patients with Crohn’s disease and 27 healthy subjects were included in the present study. Anthropometric, clinical, and 24 h urinary parameters were determined, and the [¹³C₂]oxalate absorption test was performed. Among all patients, 18 had undergone ileal resection, 9 of whom had a history of urinary stones. Compared to healthy controls, the urinary excretion values of calcium, magnesium, potassium, sulfate, creatinine, and citrate were significantly lower in patients with Crohn’s disease. Intestinal oxalate absorption, the fractional and 24 h urinary oxalate excretion, and the risk of calcium oxalate stone formation were significantly higher in patients with urolithiasis than in patients without urolithiasis or in healthy controls. Regardless of the group, between 83% and 96% of the [¹³C₂]oxalate was detected in the urine within the first 12 h after ingestion. The length of ileum resection correlated significantly with the intestinal absorption and urinary excretion of oxalate. These findings suggest that enteric hyperoxaluria can be attributed to the hyperabsorption of oxalate following extensive ileal resection. Oral supplementation of calcium and magnesium, as well as alkali citrate therapy, should be considered as treatment options for urolithiasis. Full article

Free-living amoebas can impact the excretion of macroelements and microelements in urine. The aim of the present study was to examine the concentrations of macroelements, including calcium (Ca), phosphorus (P), sodium (Na), potassium (K), and magnesium (Mg), as well as microelements such as manganese (Mn), zinc (Zn), copper (Cu), iron (Fe), and chromium (Cr), in the urine during acanthamoebiasis while considering the host’s immunological status. This is the first study to show an increase in urinary excretion of Ca, Mn, Cu, Fe, Na, and Cr, along with a decreased excretion of K, in immunocompetent mice 16 days post Acanthamoeba sp. infection. In the final phase of infection (24 dpi), there was a further decrease in urinary K excretion and a lower level of P in Acanthamoeba sp. infected immunocompetent hosts. During acanthamoebiasis in immunosuppressed hosts, increased excretion of Zn, Fe, and Cr was observed at the beginning of the infection, and increased Na excretion only at 16 days post Acanthamoeba sp. infection. Additionally, host immunosuppression affected the concentration of Fe, Cr, Zn, Cu, Mn, and Ca in urine. Full article

Introduction: The dissolved mineral content of drinking water can modify a number of excreted urinary parameters, with potential implications for kidney stone disease (KSD). The aim of this study is to investigate the variation in the mineral content of tap drinking water in the United Kingdom and discuss its implications for KSD. Methods: The mineral composition of tap water from cities across the United Kingdom was ascertained from publicly available water quality reports issued by local water supply companies using civic centre postcodes during 2021. Water variables, reported as 12-monthly average values, included total water hardness and concentrations of calcium, magnesium, sodium and sulphate. An unpaired t-test was undertaken to assess for regional differences in water composition across the United Kingdom. Results: Water composition data were available for 66 out of 76 cities in the United Kingdom: 45 in England, 8 in Scotland, 7 in Wales and 6 in Northern Ireland. The median water hardness in the United Kingdom was 120.59 mg/L CaCO₃ equivalent (range 16.02–331.50), while the median concentrations of calcium, magnesium, sodium and sulphate were 30.46 mg/L (range 5.35–128.0), 3.62 mg/L (range 0.59–31.80), 14.72 mg/L (range 2.98–57.80) and 25.36 mg/L (range 2.86–112.43), respectively. Tap water in England was markedly harder than in Scotland (192.90 mg/L vs. 32.87 mg/L as CaCO₃ equivalent; p < 0.001), which overall had the softest tap water with the lowest mineral content in the United Kingdom. Within England, the North West had the softest tap water, while the South East had the hardest water (70.00 mg/L vs. 285.75 mg/L as CaCO₃ equivalent). Conclusions: Tap water mineral content varies significantly across the United Kingdom. Depending on where one lives, drinking 2–3 L of tap water can contribute over one-third of recommended daily calcium and magnesium requirements, with possible implications for KSD incidence and recurrence. Full article

Excessive consumption of fructose (FR) leads to obesity, metabolic syndrome (MS) and insulin resistance, which are known risk factors for kidney stones. The epidemiological study has suggested the association between fructose consumption and urolithiasis, but the precise mechanism is still not well understood. Male Wistar rats were assigned for 8 weeks to three groups with different FR content in diet: RD (n = 5)—regular diet with a FR < 3%; F10 (n = 6)—regular diet with an addition of 10% Fr in drinking water; F60 (n = 5)—60% FR as a solid food. Serum concentration of FR, creatinine (Cr), insulin (Ins), triglycerides (Tg), homocysteine (HCS), uric acid (UA), calcium (Ca), phosphate (Pi), magnesium (Mg) and sodium (Na) were measured. Based on 24 h urine collection the following tests were performed: urine pH, proteinuria (PCR), excretion of N-Acetyl-(D)-Glucosaminidase (NAG), monocyte chemoattractant protein (MCP-1), uric acid (uUAEx), phosphate (uPiEx), calcium (uCaEx), magnesium (uMgEx) and sodium (uNaEx). The creatinine clearance (CrCl) was calculated. Calcium deposits in kidney sections were examined using hematoxylin and eosin (HE) and von Kossa stains. The rats on F10 and F60, as compared to the RD diet, showed a tendency for lower CrCl, higher HCS level and some features of MS as higher Ins and TG levels. Interestingly, F10 (fluid) versus F60 (solid) diet led to higher serum Ins levels. F10 and F60 versus RD demonstrated higher urinary excretion of MCP-1 and NAG which were suggestive for inflammatory injury of the proximal tubule. F10 and F60 as compared to RD showed significantly lower uUAEx, although there were no differences in clearance and fractional excretion of UA. F60 versus RD induced severe phosphaturia (>30×) and natriuria (4×) and mild calciuria. F10 versus RD induced calciuria (3×), phosphaturia (2×) and mild natriuria. Calcium phosphate stones within the tubules and interstitium were found only in rats on FR diet, respectively, in two rats from the F10 group and another two in the F60 group. The rats which developed stones were characterized by significantly higher serum insulin concentration and urinary excretion of calcium and magnesium. A fructose-rich diet may promote development of calcium stones due to proximal tubule injury and metabolic syndrome. Full article

The prevalence of metabolic syndrome (MetS) is increasing, and patients with MetS are at an increased risk of cardiovascular disease and diabetes. There is a close link between hypomagnesemia and MetS. Administration of sodium-glucose transporter 2 (SGLT2) inhibitors has been reported to increase serum magnesium levels in patients with diabetes. We investigated the alterations in renal magnesium handling in an animal model of MetS and analyzed the effects of SGLT2 inhibitors. Adult rats were fed a fructose-rich diet to induce MetS in the first 3 months and were then treated with either dapagliflozin or magnesium sulfate-containing drinking water for another 3 months. Fructose-fed animals had increased insulin resistance, hypomagnesemia, and decreased urinary magnesium excretion. Dapagliflozin treatment improved insulin resistance by decreasing glucose and insulin levels, increased serum magnesium levels, and reduced urinary magnesium excretion. Serum vitamin D and parathyroid hormone levels were decreased in fructose-fed animals, and the levels remained low despite dapagliflozin and magnesium supplementation. In the kidney, claudin-16, TRPM6/7, and FXDY expression was increased in fructose-fed animals. Dapagliflozin increased intracellular magnesium concentration, and this effect was inhibited by TRPM6 blockade and the EGFR antagonist. We concluded that high fructose intake combined with a low-magnesium diet induced MetS and hypomagnesemia. Both dapagliflozin and magnesium sulfate supplementation improved the features of MetS and increased serum magnesium levels. Expression levels of magnesium transporters such as claudin-16, TRPM6/7, and FXYD2 were increased in fructose-fed animals and in those administered dapagliflozin and magnesium sulfate. Dapagliflozin enhances TRPM6-mediated trans-epithelial magnesium transport in renal tubule cells. Full article

(1) Background: Magnesium deficiency is usually associated with type 2 diabetes mellitus (T2DM). Individuals living with T2DM with hypomagnesemia show a more rapid disease progression and have an increased risk for diabetes complications. (2) Methods: This is a cross-sectional and descriptive study in the National Institute of Nutrition and Food Technology of Tunis in Tunisia, including all adult outpatients (≥18 years old) with a diagnosis of T2DM from 1 September 2018 to 31 August 2019. The aim of this study was to evaluate the prevalence of plasmatic magnesium deficiency in a Tunisian population of T2DM and to study the relationship between magnesium status and intake, glycemic control and long-term diabetes-related complications. (3) Results: Among the 101 T2DM outpatients, 13 (12.9%) presented with a plasmatic magnesium deficiency. The mean age was 56 ± 7.9 years with a female predominance (62%, n = 63). The mean of the plasmatic magnesium level was 0.79 ± 0.11 mmol/L (0.5–1.1), and the mean of 24 h urinary magnesium excretion was 87.8 ± 53.8 mg/24 h [4.8–486.2]. HbA1c was significantly higher in the plasmatic magnesium deficiency group than the normal magnesium status group (10% ± 1.3 vs. 8.3% ± 1.9; p = 0.04), with a significant difference in participants with a poor glycemic control (HbA1c > 7%) (100%, n = 13/13 vs. 53%, n = 47/88; p = 0.001). A weak negative relationship was also found between plasmatic magnesium and HbA1c (r = −0.2, p = 0.03). Peripheral artery disease was more commonly described in individuals with low plasmatic magnesium levels than in individuals with normal levels (39%, n = 5 vs. 0%, n = 0; p < 0.001). The mean plasmatic magnesium level in participants without diabetic nephropathy and also peripheral artery disease was significantly higher compared to individuals with each long-term diabetes-related complication (0.8 mmol/L ± 0.1 vs. 0.71 mmol/L ± 0.07; p = 0.006) and (0.8 mmol/L ± 0.1 vs. 0.6 mmol/L ± 0.08; p < 0.001), respectively. (4) Conclusions: Hypomagnesemia was identified in individuals with T2DM, causing poor glycemic control and contributing to the development and progression of diabetes-related microvascular and macrovascular complications. Full article

Aquatic animals have unique physiological mechanisms to absorb and retain minerals from their diets and water. Research and development in the area of mineral nutrition of farmed fish and crustaceans have been relatively slow and major gaps exist in the knowledge of trace element requirements, physiological functions and bioavailability from feed ingredients. Quantitative dietary requirements have been reported for three macroelements (calcium, phosphorus and magnesium) and six trace minerals (zinc, iron, copper, manganese, iodine and selenium) for selected fish species. Mineral deficiency signs in fish include reduced bone mineralization, anorexia, lens cataracts (zinc), skeletal deformities (phosphorus, magnesium, zinc), fin erosion (copper, zinc), nephrocalcinosis (magnesium deficiency, selenium toxicity), thyroid hyperplasia (iodine), muscular dystrophy (selenium) and hypochromic microcytic anemia (iron). An excessive intake of minerals from either diet or gill uptake causes toxicity and therefore a fine balance between mineral deficiency and toxicity is vital for aquatic organisms to maintain their homeostasis, either through increased absorption or excretion. Release of minerals from uneaten or undigested feed and from urinary excretion can cause eutrophication of natural waters, which requires additional consideration in feed formulation. The current knowledge in mineral nutrition of fish is briefly reviewed. Full article

Growing evidence suggests that micronutrient status is adversely impacted by toxic metals (e.g., cadmium, lead, and arsenic) exposures; however, the micronutrient status of e-waste recyclers who are amongst the highest metal-exposed groups is not known. This study, therefore, assessed the micronutrient status of e-waste recyclers using dietary information (2-day 24-h recall survey) and biomarker data (whole blood and urine) among 151 participants (100 e-waste recyclers at Agbogbloshie and 51 controls at Madina Zongo from the Accra region, Ghana) in March 2017. Biomarker levels of iron (Fe), calcium (Ca), magnesium (Mg), selenium (Se), zinc (Zn) and copper (Cu) were analyzed by the ICP-MS. Linear regression models were used to assess associations ofwork-related factors and sociodemographic characteristics with micronutrient intake, blood, and urine micronutrient levels. The results showed that apart from Fe and Zn, e-waste recyclers at Agbogbloshie did not meet the day-to-day dietary requirements for Ca, Cu, Se, and Mg intake. Except for the low levels of Mg and Fe detected in blood of e-waste recyclers, all other micronutrients measured in both blood and urine of both groups fell within their reference range. Exposure to biomass burning was associated with lower blood levels of Fe, Mg, and Zn among the e-waste recyclers. Further, among e-waste recyclers, significant relationships were found between the number of years spent recycling e-waste and urinary Ca and Cu excretion. Given that, some dietary and blood levels of micronutrients were below their reference ranges, the implementation of evidence-based nutrition strategies remains necessary among e-waste recyclers to reduce their risk of becoming malnourished. Full article

The sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively new class of antidiabetic drugs that, in addition to emerging as an effective hypoglycemic treatment, have been shown to improve, in several trials, both renal and cardiovascular outcomes. In consideration of the renal site of action and the associated osmotic diuresis, a negative sodium balance has been postulated during SGLT2i administration. Although it is presumable that sodium and water depletion may contribute to some positive actions of SGLT2i, evidence is far from being conclusive and the real physiologic effects of SGLT2i on sodium remain largely unknown. Indeed, no study has yet investigated how SGLT2i change sodium balance in the long term and especially the pathways through which the natriuretic effect is expressed. Furthermore, recently, several experimental studies have identified different pathways, not directly linked to tubular sodium handling, which could contribute to the renal and cardiovascular benefits associated with SGLT2i. These compounds may also modulate urinary chloride, potassium, magnesium, phosphate, and calcium excretion. Some changes in electrolyte homeostasis are transient, whereas others may persist, suggesting that the administration of SGLT2i may affect mineral and electrolyte balances in exposed subjects. This paper will review the evidence of SGLT2i action on sodium transporters, their off-target effects and their potential role on kidney protection as well as their influence on electrolytes and mineral homeostasis. Full article

Proton-pump inhibitors (PPIs) are commonly used after kidney transplantation and there is rarely an incentive to discontinue treatment. In the general population, PPI use has been associated with hypomagnesaemia. We aimed to investigate whether PPI use is associated with plasma magnesium, 24-h urinary magnesium excretion and hypomagnesaemia, in kidney transplant recipients (KTR). Plasma magnesium and 24-h urinary magnesium excretion were measured in 686 stable outpatient KTR with a functioning allograft for ≥1 year from the TransplantLines Food and Nutrition Biobank and Cohort-Study (NCT02811835). PPIs were used by 389 KTR (56.6%). In multivariable linear regression analyses, PPI use was associated with lower plasma magnesium (β: −0.02, P = 0.02) and lower 24-h urinary magnesium excretion (β: −0.82, P < 0.001). Moreover, PPI users had a higher risk of hypomagnesaemia (plasma magnesium <0.70 mmol/L), compared with non-users (Odds Ratio (OR): 2.12; 95% confidence interval (CI) 1.43–3.15, P < 0.001). This risk tended to be highest among KTR taking high PPI dosages (>20 mg omeprazole Eq/day) and was independent of adjustment for potential confounders (OR: 2.46; 95% CI 1.32–4.57, P < 0.005). No interaction was observed between PPI use and the use of loop diuretics, thiazide diuretics, tacrolimus, or diabetes (P_interaction > 0.05). These results demonstrate that PPI use is independently associated with lower magnesium status and hypomagnesaemia in KTR. The concomitant decrease in urinary magnesium excretion indicates that this likely is the consequence of reduced intestinal magnesium absorption. Based on these results, it might be of benefit to monitor magnesium status periodically in KTR on chronic PPI therapy. Full article