Calcium Carbonate Group Research Articles

Using synchrotron based ATR-FTIR, EXAFS, and XRF to characterize the chemical compositions of TSP in industrial estate area

In Thailand, the Map Ta Phut Industrial Estate (MTPIE), a prominent industrial hub, has substantial environmental and health issues caused by industrial pollution. This study uses advanced synchrotron-based techniques, such as Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), Extended X-ray Absorption Fine Structure (EXAFS), and X-ray Fluorescence (XRF), to fully examine the chemical make-up of total suspended particulate (TSP) in the given area. Notable findings include the detection of remarkably high enrichment factors for magnesium and sulfur, indicating the presence of industrial operations. Additionally, we found that magnetite, which accounts for an average of 40 % of the total iron oxides in the samples, is the main iron oxide. The study also highlights about how calcium carbonate and different organic functional groups are found in large amounts, which shows that industrial emissions and natural sources are connected in a complex way. The findings underscore the susceptibility of children to TSP exposure, revealing increased rates of inhalation and significant health hazards. In order to safeguard public health in industrial areas such as MTPIE, it is imperative to implement more sophisticated pollution control techniques and maintain ongoing environmental monitoring.

Enzymatic hydrolysates from sea cucumber body wall prevent low calcium-induced osteoporosis by regulating calcium absorption and gut microbiota

Inadequate calcium intake or intestinal malabsorption is closely related to osteoporosis. The aim of this study was to investigate the effects of sea cucumber enzymatic hydrolysates (SCEH) prepared from body wall on calcium absorption in calcium-deficient rats. Fifty-six female Sprague-Dawley rats on a low calcium diet that induced osteoporosis were fed SCEH and calcium carbonate for 3 months. The results showed that oral administration of SCEH and calcium carbonate both increased the body weight (bw) and bone mineral density (BMD) in calcium-deficient rats to varying degrees, thereby alleviating the adverse effects of osteoporosis. In addition, oral administration of a combination of SCEH (2000 mg/kg bw/day) and calcium (333 mg/kg bw/day) upregulated the expression of calcium transporter genes (TRPV6 and Calbindin-D9k) in the intestines, increased serum 1,25(OH)2D3 levels and BMD, decreased trabecular bone separation, and inhibited parathyroid hormone (PTH) release in calcium-deficient rats compared to calcium carbonate groups. Thus, this combination promoted calcium absorption and improved the efficiency of calcium utilization. These results might be associated with a higher short chain fatty acid (SCFA) level in the gut and an increased abundance of butyrate and acetate producing bacteria, such as Christensenellaceae R7 group, UCG-005 and Clostridium UCG-014. Therefore, a diet containing SCEH and calcium combinations might be recommended to increase bone mass and inhibit osteoporosis.

New insight into highly efficient removal of tetracycline by calcined hydroxyapatite activated peroxymonosulfate: The role of calcium carbonate and phosphate group

Tetracycline (TC) is an important antibiotic extensively used in livestock breeding and aquaculture, and so an effective removal strategy is urgently needed. This study explores the use of a series of hydroxyapatite calcinated at different temperatures (300, 400, 500, 600, and 700 °C) to activate peroxymonosulfate (PMS) for the removal of TC. The optimal conditions for the removal of 10 mg/L TC using hydroxyapatite calcinated at 600 °C (CHAP600) as a catalyst were determined to be: pH of 6.0, a catalyst dosage of 0.2 g/L and a PMS concentration of 0.3 mM. Under these conditions, the removal efficiency of TC reached 94 %. The potential degradation pathway of TC was proposed by identifying the intermediates using High Performance Liquid Chromatography/Triple Quad mass spectrometry. The characterization analysis revealed that the presence of calcium carbonate on the surface of CHAP600 promoted the generation of singlet oxygen (1O2). Additionally, the phosphate group in CHAP600 served as a catalyst for the production of sulfate radicals (SO4·−) from PMS, which subsequently react with hydroxyl or surface hydroxyl group to generate hydroxyl radicals (·OH). And the active species 1O2 is the most significant contributor to the catalytic degradation process of TC by CHAP600 activated PMS, followed by ·OH, and then SO4·−. This study provides new insight for the mechanism of removing organic contaminants using PMS activated with calcined hydroxyapatite.

The bone-protective benefits of amino-conjugated calcium in an ovariectomized (OVX) rat model

Low bone density, fragility, and microarchitectural disintegration are the symptoms of osteoporosis. An imbalance between bone growth and resorption can lead to osteoporosis. This study evaluated the effects of amino-calcium (AC) on bone protection in ovariectomized control group (NC) rats. Amino-calcium (AC) was characterized using Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), and nuclear magnetic resonance spectroscopy analyses (NMR). After determining the biocompatibility of amino-calcium (AC) with MC3T3-E1 cells, alkaline phosphatase staining revealed significant changes on day 7. Three of the four groups underwent ovariectomy, whereas one group received a placebo. On micro-computed tomography, in vivo, data showed increased bone volume fraction in the femoral head and shaft areas in the amino-calcium (AC) group. Hematoxylin and eosin staining showed a bone mass and architectural protection in the amino-calcium (AC) group compared with the calcium carbonate and OVX control group. RNA sequencing analysis revealed high expression of osteogenesis-related genes in MC3T3-E1 cells. RNA sequencing revealed a significant fold change in the expression of integrin-binding sialoprotein (IBSP), bone gamma-carboxyglutamate proteins 1 and 2(BGLAP1 and BGLAP2), and periostin (POSTN). The study concluded that supplementing the OVX rats with calcium enhanced bone protection.

Microbial traces found in microdolomite associated with seep-related shallow gas hydrate

Recently, microdolomite grains with a diameter of about 30–150 μm were discovered within seep-related shallow gas hydrate in the eastern margin of the Japan Sea, and the preliminary assumption has been that their formation is mediated by microbially secreted extracellular polymeric substances (EPS). To verify this interpretation, the present study investigates the characteristics of minerals and organic matter inside the microdolomite grains. Observation by polarizing microscopy reveals that the microdolomite grains generally consist of combinations of distinct cores and external cements. The cores are mostly dark or cloudy and their abundance does not show clear depth dependence, while the external cements are generally isopachous in the shallow part and polygonal in the deeper portions. To further clarify the characteristics of these cores and external cements, thin-foil sections were prepared from two major types of microdolomite, one with a dark core and polygonal external cement, and one with a cloudy core and isopachous external cement. These thin-foil sections were then analyzed by scanning transmission X-ray microscopy (STXM) and transmission electron microscopy (TEM). In the dark core, fibriform pores of about 100 nm diameter were observed to be closely related with amorphous calcium carbonate (ACC) and carboxy groups, likely created by heterogeneous nucleation on microbial EPS surfaces. The polygonal external cement is composed of monocrystalline dolomite, representing slow crystal growth in the deeper part where hydrate formation is less active. On the other hand, the observed cloudy core and the isopachous external cement are, respectively, composed of scattered and accumulated rhombohedral dolomite crystals, presumably resulting from homogeneous nucleation in saline pockets of rapidly growing hydrate and subsequent crystal accumulation on the surface of spherical oil films.

Chondroitin sulfate alleviates osteoporosis caused by calcium deficiency by regulating lipid metabolism

The use of non-drug intervention for calcium deficiency has attracted attention in recent years. Although calcium carbonate is the preferred raw material for calcium supplementation, there are few reports on the mechanism of the combined action of chondroitin sulfate and calcium to alleviate osteoporosis from the perspective of gut microbiota and metabolomics. In this study, a rat model of osteoporosis was established by feeding a low-calcium diet. The intestinal microbiota abundance, fecal and plasma metabolite expression levels of rats fed a basal diet, a low-calcium diet, a low-calcium diet plus calcium carbonate, and a low-calcium diet plus chondroitin sulfate were compared. The results showed that compared with the low calcium group, the calcium content and bone mineral density of femur were significantly increased in the calcium carbonate and chondroitin sulfate groups. 16 S rRNA sequencing and metabolomics analysis showed that chondroitin sulfate intervention could reduce short-chain fatty acid synthesis of intestinal flora, slow down inflammatory response, inhibit osteoclast differentiation, promote calcium absorption and antioxidant mechanism, and alleviate osteoporosis in low-calcium feeding rats. Correlation analysis showed that the selected intestinal flora was significantly correlated with metabolites enriched in feces and plasma. This study provides scientific evidence of the potential impact of chondroitin sulfate as a dietary supplement for patients with osteoporosis.

Effects of calcium salts on experimental characterizations of sodium alginate hydrogels and the drug release of electrospun naringin-loaded microspheres hybrid hydrogel scaffolds

This study utilized four calcium sources (calcium carbonate, hydroxyapatite, calcium sulfate, and calcium chloride) combined with sodium alginate to form different hydrogel scaffolds and investigated differences in their related properties. In addition, the drug release behavior of the scaffolds was characterized by naringin release in vitro. The calcium carbonate and hydroxyapatite groups formed homogeneous hydrogels with better physical and mechanical properties. The hydroxyapatite and calcium sulfate groups had better sustained release ability. These results highlight the importance of proper calcium source selection when preparing sodium alginate hydrogels and demonstrate that hydroxyapatite as a calcium source has potential application in bone tissue engineering.

Suppression of high bone remodelling by E'Jiao in ovariectomised rats.

The current prevention options for postmenopausal osteoporosis are very limited. E'Jiao is a collagen-rich traditional Chinese medicine with the potential to prevent osteoporosis but more comprehensive investigations are lacking. This study aimed to investigate the skeletal protective effects of E'Jiao in a rat model of osteoporosis caused by ovariectomy. Female Sprague Dawley rats (n=42) were randomly assigned into baseline, sham, ovariectomised (OVX) control, OVX-treated with low-dose (0.26g/kg), medium dose (0.53g/kg) and high dose E'Jiao (1.06g/kg), as well as calcium carbonate (1% w/v) groups. Daily treatment through oral gavage was initiated 7 days after OVX. The rats were euthanised after eight weeks of treatment. Bone mineral density and content were measured at baseline, 1 and 2 months after treatment. Blood was collected for the measurement of bone remodelling markers. Femur and tibial bones were collected for histomorphometry and biomechanical strength analysis. Untreated OVX rats showed high bone remodelling marked by the increased bone formation and bone resorption markers, as well as increased mineralising surface/bone surface ratio. In addition, osteoclast surface and single-labelled surface were increased while mineral apposition rate was reduced in the untreated OVX rats. These changes were antagonised by E'Jiao at all doses. However, the structural, cellular and biomechanical parameters were not affected by ovariectomy and treatment. In conclusion, E'Jiao prevented high bone remodelling during oestrogen deficiency but a long-term study will be required to establish its effects on structural and biomechanical changes due to oestrogen deficiency.

Effects of lanthanum carbonate and calcium carbonate on cardiovascular calcification in hemodialysis patients: A systematic review and meta-analysis.

This paper was written to systematically review and meta-analyze the evidence on the efficacy of lanthanum carbonate (LC) and calcium carbonate (CC) and the risk of cardiovascular calcification on hemodialysis (HD) patients. The Cochrane library, PubMed, Web of Science, Chinese journal full-text database (CNKI), WANGFANG DATA, and Sino Med were searched between January 1946 and December 2020. The literature with respect to the randomized controlled clinical trial comparing LC and CC in HD patients was selected. The main outcomes include coronary artery calcification score (CACS), cardiovascular events, and serum phosphorus (mmol/L). The statistical program used for meta-analysis was Stata V14.0. Of 388 original titles screened, data was extracted from 9 studies (625 participants). LC can significantly reduce the progression of coronary artery calcification compared to CC (standardized mean deviation (SMD) = -0.59, 95% CI: -0.94 to -0.25, p < 0.01). The LC group had lower serum phosphorus levels (SMD = -1.35, 95% CI: -2.33 to -0.36, p < 0.01), lower serum calcium levels (SMD = -1.03, 95% CI: -1.83 to -0.23, p = 0.012), and lower fibroblast growth factor 23 (FGF-23) level (SMD = -4.80, 95% CI: -7.96 to -1.64, p = 0.003) than the CC group. The Egger regression test of CACS showed no potential publication bias (p = 0.72). Compared with CC, LC can significantly delay the process of coronary artery calcification, and at the same time reduce patients' serum phosphate, serum calcium, and FGF-23. Therefore, we recommend LC as a phosphorus-lowering drug for HD patients.

Investigating the Preventive Effects of 99Tc-Methylenediphosphonate on a Glucocorticoid-Induced Osteoporosis Rabbit Model.

Osteoporosis is a worldwide healthcare challenge. Conventional medications for osteoporosis prevention are not clinically effective or associated with gastrointestinal tract adverse effects. The present study aimed to comparatively investigate the effects of technetium-99 conjugated with methylene diphosphonate (99Tc-MDP) and calcium carbonate and alendronate on the prevention and treatment of osteoporosis in glucocorticoid-induced osteoporosis rabbit model through evaluating bone alkaline phosphatase (B-ALP), TRAP-5b levels and histopathological parameters. Forty healthy female New Zealand rabbits were randomly divided into five groups (each n=8), including control group (Control Group), osteoporosis model group (GIO Group), osteoporosis model + 99Tc-MDP group (99Tc-MDP Group), osteoporosis model + alendronate group (Alendronate Group), and osteoporosis model + calcium carbonate group (calcium carbonate Group). Animals in each group were treated with corresponding interventions for 14 weeks. The blood samples were collected at the first and 14th week, and B-ALP and TRAP-5b levels were detected by enzyme- linked immunosorbent assay (ELISA). The rabbits were anesthetized at the 14th week, and pathological cytological observation was performed on both femurs. The age and weights of rabbits in different groups had no statistically significant differences (P>0.05). B-ALP levels in serum of all groups except for the Control Group decreased after treatment, but the differences were not statistically significant (P>0.05). TRAP-5b levels in serum of all groups increased after treatment. Specifically, differences in the GIO Group and calcium carbonate group were statistically significant (P<0.05), while differences in 99Tc-MDP Group and alendronate Group were not statistically significant (P<0.05). Pathological sections revealed that the control group presented normal bone tissue morphology. The bone tissue morphology of the 99Tc- MDP group and alendronate group was similar to control group and GIO group. Moreover, the calcium carbonate group and GIO group exhibited similar bone tissue morphology. 99Tc-MDP has a preventive effect on the glucocorticoid-induced osteoporotic rabbit model. This osteoporosis preventive effect might be attributed to the capacities of 99Tc-MDP in promoting the osteoblasts generation and inhibiting the generation and reducing the activity of osteoclasts.

MO585EFFECTS OF LANTHANUM CARBONATE AND CALCIUM CARBONATE ON CARDIOVASCULAR CALCIFICATION IN HEMODIALYSIS PATIENTS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Background and Aims Commonly used phosphorus-lowering drugs include calcium-containing phosphate-binding agents and non-calcium-containing phosphate-binding agents, the latter mainly including lanthanum carbonate (LC). In recent years, some studies have explored the effect of lanthanum carbonate compared with calcium carbonate on serum calcium. However, the results are different. Therefore, we conducted this review to systematically review and meta-analyze evidence on the efficacy of lanthanum carbonate and calcium carbonate (CC) and the risk of cardiovascular calcification in hemodialysis (HD) patients, and to provide reference for phosphorus-lowering drugs in HD patients. Method The Cochrane library, PubMed, Web of Science, Chinese journal full-text database (CNKI), WANGFANG DATA and Sino Med were searched between January 1946 and December 2020. The literatures with respect to the randomized controlled clinical trial comparing lanthanum carbonate and calcium carbonate in HD patients were selected. The two evaluators independently collected the data according to the retrieval strategy, screened the literatures according to the inclusion criteria and exclusion criteria, and summarized the literatures that met the criteria. The risk ratio (RR) and 95% confidence interval (CI) were used to represent the counting data. The standard deviation from mean (SMD) and 95%CI were used to represent the continuous variables. Forest plots, sensitivity analysis, Egger regression test and TSA were used to summarized the test performance characteristics. Results Of 388 original titles screened, data was extracted from 9 studies included 625 participants (Table 1). There was moderate-certainty evidence from 9 trials (625 participants) that LC can significantly reduce the progression of coronary artery calcification than CC (SMD= -0.59, 95%CI -0.94 to -0.25, P&amp;lt; 0.01) (Figure 2). The serum phosphorus level in the LC group was significantly lower than that in the CC group (SMD= -1.35, 95%CI: -2.33 to -0.36, P&amp;lt; 0.01), and the serum calcium level was significantly reduced (SMD= -1.03, 95% CI: -1.83 to -0.23, P= 0.012). The fibroblast growth factor 23 (FGF-23) level in the LC group was significantly lower than that in the CC group (SMD= -4.80, 95%CI: -7.96 to -1.64, P= 0.003). The Egger regression test of coronary artery calcification score (CACS) showed no potential publication bias (P= 0.72). Conclusion In this systematic review, compared with calcium carbonate, lanthanum carbonate can significantly delay the process of coronary artery calcification, and at the same time reduce the patient's serum phosphate, serum calcium and FGF-23. Therefore, we recommend LC as phosphorus-lowering drugs for HD patients.

Effect of Treating Hyperphosphatemia With Lanthanum Carbonate vs Calcium Carbonate on Cardiovascular Events in Patients With Chronic Kidney Disease Undergoing Hemodialysis

Among patients with hyperphosphatemia undergoing dialysis, it is unclear whether non-calcium-based phosphate binders are more effective than calcium-based binders for reducing cardiovascular events. To determine whether lanthanum carbonate reduces cardiovascular events compared with calcium carbonate in patients with hyperphosphatemia at risk of vascular calcification undergoing hemodialysis. Open-label, randomized, parallel-group clinical trial with blinded end point adjudication performed in 2374 patients with chronic kidney disease from 273 hemodialysis facilities in Japan. Eligible patients had hyperphosphatemia and 1 or more risk factors for vascular calcification (ie, ≥65 years, postmenopausal, diabetes). Enrollment occurred from November 2011 to July 2014; follow-up ended June 2018. Patients were randomized to receive either lanthanum carbonate (n = 1154) or calcium carbonate (n = 1155) and titrated to achieve serum phosphate levels of between 3.5 mg/dL and 6.0 mg/dL. The primary outcome was a composite cardiovascular event (cardiovascular death, nonfatal myocardial infarction or stroke, unstable angina, transient ischemic attack, or hospitalization for heart failure or ventricular arrhythmia). Secondary outcomes included overall survival, secondary hyperparathyroidism-free survival, hip fracture-free survival, and adverse events. Among 2309 randomized patients (median age, 69 years; 40.5% women), 1851 (80.2%) completed the trial. After a median follow-up of 3.16 years, cardiovascular events occurred in 147 of 1063 patients in the lanthanum calcium group and 134 of 1072 patients in the calcium carbonate group (incidence rate, 4.80 vs 4.30 per 100 person-years; difference 0.50 per 100 person-years [95% CI, -0.57 to 1.56]; hazard ratio [HR], 1.11 [95%, CI, 0.88 to 1.41], P = .37). There were no significant differences in all-cause death (difference, 0.43 per 100 person-years [95% CI, -0.63 to 1.49]; HR, 1.10 [95% CI, 0.88 to 1.37]; P = .42) or hip fracture (difference, 0.10 per 100 person-years [95% CI, -0.26 to 0.47]; HR, 1.21 [95% CI, 0.62 to 2.35]; P = .58). The lanthanum carbonate group had an increased risk of cardiovascular death (difference, 0.61 per 100 person-years [95% CI, 0.02 to 1.21]; HR, 1.51 [95% CI, 1.01 to 2.27]; P = .045) and secondary hyperparathyroidism (difference, 1.34 [95% CI, 0.49 to 2.19]; HR, 1.62 [95% CI, 1.19 to 2.20]; P = .002). Adverse events occurred in 282 (25.7%) in the lanthanum carbonate group and 259 (23.4%) in the calcium carbonate groups. Among patients undergoing hemodialysis with hyperphosphatemia and at least 1 vascular calcification risk factor, treatment of hyperphosphatemia with lanthanum carbonate compared with calcium carbonate did not result in a significant difference in composite cardiovascular events. However, the event rate was low, and the findings may not apply to patients at higher risk. ClinicalTrials.gov Identifier: NCT01578200; UMIN Clinical Trial Registry Identifier: UMIN000006815.

Calcium Carbonate Attenuates Withdrawal and Reduces Craving: A Randomized Controlled Trial in Alcohol-Dependent Patients

Introduction: Preclinical studies have shown that calcium seems to be the active component of the anti-craving drug acamprosate (Ca²⁺ bis-acetyl-homotaurinate). Clinical effects in humans have also indicated an association between increased calcium plasma concentration due to acamprosate treatment and better outcome relating to time to relapse and cumulative abstinence. In contrast, low calcium concentration in alcohol-dependent patients was related with craving for alcohol. The main goal of the trial was to investigate whether an oral calcium administration is able to affect craving, withdrawal, and relapse risk in alcohol-dependent patients. Methods: We conducted a single-blind, randomized, monocentric, controlled clinical two-arm trial in alcohol-dependent patients (Clinical Trials Registration: DRKS00011293). A total of 55 alcohol-dependent subjects received calcium carbonate (800 mg + 5 μg vitamin D) versus sodium bicarbonate (1,000 mg) daily during the 14 days of inpatient alcohol-withdrawal treatment. Results: Based on an intention-to-treat protocol, withdrawal intensity (assessed with CIWA-Ar) in the calcium carbonate group attenuated faster than in the sodium bicarbonate subgroup. Alcohol craving (assessed with OCDS) in the calcium carbonate subgroup was also significantly reduced versus the sodium bicarbonate subgroup. Conclusion: Our data support earlier findings and show that treatment with calcium carbonate during alcohol withdrawal reduces symptoms of alcohol withdrawal as well as alcohol craving in a controlled clinical pilot study. Mode of actions will need to be determined to allow the further development of pharmacological interventions beyond Ca²⁺ bis-acetyl-homotaurinate.

Comparison of Sevelamer and Calcium Carbonate in Prevention of Hypomagnesemia in Hemodialysis Patients.

Background:Chronic kidney disease (CKD) is a life-threatening disease with numerous complications. Hemodialysis (HD) patients are prone to magnesium deficiency due to malnutrition, which can cause cardiovascular complications and increase mortality. The present study aimed to investigate the effects of sevelamer and calcium carbonate, as phosphate binders, on serum levels of magnesium, calcium, and phosphorus in HD patients.Methods:A parallel clinical trial was conducted on 54 patients undergoing HD at Kosar Hospital of Semnan. The inclusion criteria were end-stage renal disease (ESRD), alternative HD treatment for at least 3 months 3 times a week, and serum phosphate levels greater than 4.5 mg/dL. The participants were randomly assigned to two groups of sevelamer (n = 27) and calcium carbonate (n = 27). If the participants were taking a phosphate binder, they were asked to stop it for 3 weeks. Participants in the sevelamer group received 800 mg of sevelamer at most three times a day and those in the calcium carbonate group were treated with 500 mg of calcium carbonate at most 3 times a day. Before and 3 months after the intervention, the serum levels of calcium, magnesium, and phosphorus were measured through the Arsenazo method using the Pars Azmun kit in the Selectra auto-analyzer. Twenty-one patients in the sevelamer group and 22 patients in the calcium carbonate group finished the study.Results:The results showed that calcium carbonate and sevelamer increased serum magnesium level by 0.20 (P = 0.028) and 0.26 (P = 0.002), on average, which were statistically significant. The administration of calcium carbonate did not significantly change serum calcium levels (P = 0.53), whereas sevelamer reduced serum calcium levels by 0.23 (P = 0.017), on average. This reduction was statistically significant. The results also indicated that none of the calcium carbonate (P = 0.099) and sevelamer (P = 0.543) caused significant changes in serum phosphorus levels. The study findings showed no significant difference between the two groups in terms of changes in the serum levels of magnesium (0.590), calcium (0.116), and phosphorus (0.113).Conclusions:Both drugs (Sevelamer and calcium carbonate) prevented hypomagnesemia and increased serum magnesium levels, but no significant differences were found in blood levels of calcium, phosphorus, and magnesium compared to the two drugs. Considering the effect of magnesium on cardiovascular diseases, increasing the serum magnesium levels through the administration of calcium carbonate and sevelamer can prevent the likelihood of cardiovascular diseases. However, none of the studied drugs was superior to the other in this regard.

Calcium Carbonate for Elemental Lead Ingestions: Effect of Alkalinization on Elemental Lead Solubility in a Simulated Gastric Environment.

Acute ingestion of elemental lead foreign bodies has resulted in multiple pediatric deaths. Elemental lead is relatively insoluble at alkaline pH. Furthermore, calcium decreases lead absorption by interfering with the lead absorptive receptor. We hypothesize that alkalinization of gastric fluid with an oral calcium-containing agent, such as calcium carbonate, will decrease lead solubility, thus reducing the potential for systemic lead absorption and toxicity. This was an in vitro controlled study. One lead sphere (00 buckshot, cast 30 days prior) was randomly placed in each of ten tubes containing 20 mL simulated gastric fluid, with five tubes having 500 mg calcium carbonate added at 20 min and 140 min. We measured the fluid pH and the lead concentrations hourly for 4 h. We compared the median amount of total lead liberated after 4 h between the two groups using the Mann-Whitney U test. The pH of the gastric fluid only tubes remained 1 at every measurement, and the pH of the gastric fluid + calcium carbonate tubes was 6 at every measurement. At hour 4, the total amount of lead liberated in the soluble fraction in the control group vs the calcium carbonate group was 850 vs 12.4 mcg (95% CI for absolute difference: 605-964 mcg; p = 0.0079). Calcium carbonate antacid alkalinizes gastric fluid pH and dramatically decreases the total amount of solubilized lead by 60-fold. This project lends foundational evidence to a low-cost, widely available, pre-hospital strategy to decrease lead absorption after acute elemental lead ingestions.

Effect of Sevelamer on Calciprotein Particles in Hemodialysis Patients: The Sevelamer Versus Calcium to Reduce Fetuin-A-Containing Calciprotein Particles in Dialysis (SCaRF) Randomized Controlled Trial

IntroductionCalciprotein particles (CPPs) are potentially modifiable mediators of phosphate toxicity in patients with kidney disease. We compared the effects of calcium carbonate (CC) and the non–calcium-based phosphate binder sevelamer on CPP levels in patients undergoing hemodialysis (HD). We hypothesized that treatment with sevelamer would achieve greater reductions in amorphous calcium phosphate–containing CPP (CPP-1) and hydroxyapatite-containing CPP (CPP-2) owing to reduced calcium loading and anti-inflammatory pleiotropic effects.MethodsWe conducted an open-label, randomized controlled trial (RCT) in which 31 stable prevalent HD patients were allocated to receive either sevelamer hydrochloride (SH), sevelamer carbonate (SC), or CC for 24 weeks. Dual primary endpoints were the between groups differences in serum CPP-1 and CPP-2 levels at 24 weeks in SH + SC–treated versus CC-treated patients. Effects on aortic pulse wave velocity (aPWV), inflammatory cytokines (interleukin-6 and -8), and effects across individual treatment arms were also assessed.ResultsSerum CPP-1, but not CPP-2, levels were lower in those randomly assigned to the sevelamer (SH + SC) group compared with the CC group at 24 weeks (–70%, 95% confidence interval [CI] –90% to –15%, P = 0.02). In subgroup analysis, this effect was confined to those receiving SC (–83.4%, 95% CI –95.7% to –36.8%, P = 0.01). aPWV and interleukin-8 levels were also lower in those who received sevelamer compared with CC at 24 weeks (–2.0 m/s, 95% CI –2.9 to –1.1; –57%, 95% CI –73% to –30%, respectively, both P = 0.01). Conventional markers of mineral metabolism remained stable across all treatment groups.DiscussionCompared with treatment with CC, use of sevelamer for 24 weeks was associated with lower serum CPP-1 levels and a reduction in aPWV and systemic inflammation.

P0272COMPARATIVE GUT MICROBIOME DIFFERENCES BETWEEN FERRIC CITRATE AND CALCIUM CARBONATE PHOSPHATE BINDER TREATMENT IN HEMODIALYSIS PATIENTS

Abstract Background and Aims Gut microbiome alteration increases uremic toxin levels inducing chronic inflammation and leading morbidity and mortality in patients with chronic kidney disease. Phosphate-binding agents may potentially change the composition of the gut microbiota. However, the limited clinical study investigates the microbiome difference between iron-containing and calcium-containing phosphate binders. The aim of this study was to compare the microbiota composition in hemodialysis patients treated with ferric citrate or calcium carbonate. Method The stool microbiota was investigated in hemodialysis patients with ferric citrate used (n=8) and calcium carbonate used (n=46) by 16S rRNA next-generation gene sequencing profiling. The altered microbiota between two different phosphate binders was analyzed. Differences in the microbial composition of the two patient groups were assessed using linear discriminant analysis effect size. Results Hemodialysis patients with calcium carbonate used revealed significantly reduced microbial species diversity (Shannon index and Simpson index) and increased microbial dysbiosis index compared with ferric citrate users. Compared to patients taking calcium carbonate, a distinct microbial community structure in patients taking ferric citrate, with an increased abundance of Bacteroidetes phylum and decreased abundance of phylum Firmicutes. In comparison between two phosphate binder users, members of the order Lactobacillales were prominent in calcium carbonate therapy, including family Streptococcaceae and genus Streptococcus. In contrast, taxa of the genus Ruminococcaceae, Flavonifractor, and Cronobacter were enriched in ferric citrate phosphate binder users. Conclusion The fecal microbiota was richer and more diverse in the ferric citrate group than in the calcium carbonate group. Hemodialysis patients with ferric citrate used were associated with differences in the gut microbiome composition compared to calcium carbonate users.

Comparison of the effects of lanthanum carbonate and calcium carbonate on the progression of cardiac valvular calcification after initiation of hemodialysis

BackgroundAlthough mineral metabolism disorder influences cardiac valvular calcification (CVC), few previous studies have examined the effects of non-calcium-containing and calcium-containing phosphate binders on CVC in maintenance hemodialysis patients. The aim of the present study was to compare the effects of lanthanum carbonate (LC) with calcium carbonate (CC) on the progression of CVC in patients who initiated maintenance hemodialysis and to investigate clinical factors related to CVC.MethodsThe current study included 50 subjects (mean age 65 years, 72% males) from our previous randomized controlled trial (LC group, N = 24; CC group, N = 26). CVC was evaluated as CVC score (CVCS) using echocardiography at baseline and 18 months after initiation of hemodialysis. We compared CVCS and the changes between the two groups. We also analyzed the associations between CVCS and any other clinical factors including arterial plaque score (PS) and serum phosphorus levels.ResultsBaseline characteristics of study participants including CVCS were almost comparable between the two groups. At 18 months, there were no significant differences in mineral metabolic markers or CVCS between the two groups, and CVCS were significantly correlated with PS (r = 0.39, p < 0.01). Furthermore, changes in CVCS were significantly correlated with average phosphorus levels (r = 0.36, p < 0.05), which were significantly higher in high serum phosphorus and high PS group compared to low serum phosphorus and low PS group (p < 0.05).ConclusionsIn the present study, there were no significant differences between LC and CC with regard to progression of CVC. However, serum phosphorus levels and arterial plaque seem to be important for the progression and formation of CVC in hemodialysis patients.

Efficacy and safety of ossein-hydroxyapatite complex versus calcium carbonate to prevent bone loss

Objective: This study aimed to compare the efficacy and safety of ossein-hydroxyapatite complex (OHC) versus calcium carbonate (CC) for preventing bone loss during perimenopause in current clinical practice.Methods: The prospective, comparative, non-randomized, open-label study included 851 perimenopausal women with basal bone mineral density (BMD) T-score ≥−2 standard deviations (SDs). Participants received either OHC (712 mg calcium/day) or CC (1000 mg calcium/day) over 3 years. BMD was evaluated by dual-energy X-ray absorptiometry at the lumbar spine (L2–L4) at baseline and after 18 and 36 months of follow-up. Adverse drug reactions (ADRs) were also recorded.Results: In women receiving OHC, BMD at the L2–L4 site remained stable over the 3-year follow-up period (mean [SD] change 0.00 [0.11] g/cm2). BMD in the CC arm decreased −3.1% (mean [SD] − 0.03 [0.11] g/cm2). Between-group differences were statistically significant (p < 0.001) and favored OHC. ADRs were more frequent in the CC group (7.7% vs. 2.7% in the OHC group; p = 0.001), affecting primarily the gastrointestinal system.Conclusion: OHC showed greater efficacy and tolerability than CC for bone loss prevention in perimenopausal women in real-world practice. As the daily dose of calcium was higher in the CC group, the differences might be linked to the ossein compound in OHC.

Effects of lanthanum carbonate on bone markers and bone mineral density in incident hemodialysis patients.

Recent clinical studies demonstrated the favorable effects of calcium-free phosphate binders on mortality and vascular calcification in hemodialysis (HD) patients. The aim of the present study was to investigate the effects of a calcium-free phosphate binder, lanthanum carbonate (LC), on bone metabolic markers and bone mineral density (BMD), compared with those of calcium carbonate (CC), in subjects new to HD. The present study included 65 subjects from our previous randomized controlled trial (LC group, N = 31; CC group, N = 34). We investigated the effects of LC on serum intact parathyroid hormone (iPTH), osteocalcin (OC), bone-specific alkaline phosphatase (BAP), tartrate-resistant acid phosphatase 5b (TRACP-5b), sclerostin levels, and BMD, compared with those of CC in patients new to HD at baseline and at 12 and 18months. Serum OC levels at 18months were significantly higher in the LC group than in the CC group. During the study period, serum BAP and TRACP-5b and iPTH levels tended to be higher in the LC group than in the CC group. At 18months, the percentage of low bone turnover, based on a serum BAP cutoff value, was significantly lower in the LC group than in the CC group. There were no significant differences in the lumbar and femoral BMD between the two groups. The results of the present study suggest that LC has potential in preventing low bone turnover, in comparison to CC, in patients new to HD.