Pharmacodynamic Exposure-Response Analysis of Fracture Count Data Following Treatment with Burosumab in Patients with XLH.

X-linked hypophosphatemia (XLH) is a rare genetic disorder caused by excessive fibroblast growth factor 23 (FGF23), leading to low serum phosphate levels resulting in increased risk of fractures and pseudofractures. Burosumab is indicated for the treatment of XLH. In this work, we aimed to understand the quantitative relationship between burosumab-treatment-induced improvements in serum phosphate and reduction in fracture and pseudofracture counts in adults with XLH. Burosumab pharmacokinetic pharmacodynamic data from nine clinical studies were first utilized to update a prior population pharmacokinetic pharmacodynamic (PPKPD) model. The updated PPKPD model predictions for serum phosphate exposures along with other factors (i.e., time and treatment) were utilized to evaluate the relationship on fracture counts using Poisson model. The updated PPKPD model suggested that burosumab concentrations required for 50% of maximal effect decreased with increasing baseline serum phosphate levels. A Poisson model with time from baseline, average serum phosphate, and burosumab treatment described the time-varying fracture and pseudofracture count data appropriately. The model suggested a baseline rate of fracture and pseudofracture of 1.87 counts. The model predicted that fracture counts decrease by 1% each week, and by 23% with each unit increase (1.0 mg/dL) in average serum phosphate from lower limit of normal (2.5 mg/dL). An additional 1% decrease in fracture count each week was attributed to burosumab treatment that could not be explained by improvements in serum phosphate. Overall, the model quantified the relationship between burosumab-treatment-induced serum phosphate improvements and reduction in fracture and pseudofracture counts in patients with XLH over time.

Association Between the Serum Phosphate Levels and Hospital Mortality as Well as 90-Day Mortality Among Critically Ill Patients with Chronic Obstructive Pulmonary Disease: A Retrospective Cohort Study.

Purpose: COPD patients frequently have abnormal serum phosphorus levels. The objective of this study was to examine the correlation between serum phosphorus levels with hospital and 90-day mortality in critically ill patients with COPD. Patients and Methods: The MIMIC IV database was used for this retrospective cohort analysis. We extracted demographics, vital signs, laboratory tests, comorbidity, antibiotic usage, ventilation and scoring systems within the first 24 hours of ICU admission. Restricted cubic splines and multivariate cox regression analysis models were used to evaluate the connection between serum phosphorus with hospital and 90-day mortality. We assessed and classified various factors including gender, age, renal disease, severe liver disease, the utilization of antibiotics and congestive heart failure. Results: We included a total of 3611 patients with COPD, with a median age of 70.7 years. After adjusting for all other factors, we observed a significant positive association between serum phosphate levels with both hospital mortality (HR 1.19, 95% CI: 1.07-1.31, p<0.001) and 90-day mortality (HR 1.15, 95% CI: 1.06-1.24, p<0.001). Compared to the medium group (Q2 ≥3.15, <4.0), the adjusted hazard ratios for hospital mortality were 1.47 (95% CI: 1.08-2, p=0.013), and 1.31 (95% CI: 1.06-1.61, p=0.013) for 90-day mortality in the high group (Q3≥4.0). Hospital mortality decreased at serum phosphate levels below 3.8 mg/dl (HR 0.664, 95% CI: 0.468-0.943, p=0.022), but increased for both hospital (HR 1.312, 95% CI: 1.141-1.509, p<0.001) and 90-day mortality (HR 1.236, 95% CI: 1.102-1.386, p<0.001) when levels were above 3.8 mg/dl. Subgroup and sensitivity analyses yielded consistent results. Conclusion: In critical ill COPD patients, this study demonstrated a non-linear association between serum phosphate levels and both hospital and 90-day mortality. Notably, there was an inflection point at 3.8 mg/dl, indicating a significant shift in outcomes. Future prospective research is necessary to validate this correlation.

Association between serum phosphate, magnesium, calcium and aortic valve sclerosis: a propensity score-matched case-control study.

OBJECTIVES: Aortic valve sclerosis has been proposed to signify greater cardiovascular risk; the correlation between serum trace elements and aortic valve sclerosis has been reported. Therefore, an in-depth exploration of the risk factors for aortic valve sclerosis and early intervention may reduce the risk of cardiovascular disease. METHODS: In this study, Patients with aortic valve sclerosis and non-aortic valve sclerosis who underwent echocardiographic diagnosis in the People's Hospital of Xinjiang Uygur Autonomous Region during the period from 2019 to 2021 were selected for this study. The correlation between aortic valve sclerosis and serum phosphorus, calcium, and magnesium levels was explored using the propensity score matching technique by pairing the two groups of patients 1:1. RESULTS: A total of 1,533 non-aortic valve sclerosis and 1,533 aortic valve sclerosis patients were included. Logistic regression analysis showed that serum magnesium [OR: 0.346; 95%CI: 0.227, 0.528] and serum calcium [OR: 7.022; 95%CI: 4.755, 10.369] were influential factors. Patients with low, intermediate, and high serum magnesium levels had a significantly lower risk of aortic valve sclerosis compared to patients with very low micronutrient levels (p < 0.05). Comparatively, patients with low or high serum calcium levels had an elevated risk of aortic valve sclerosis (p < 0.05). CONCLUSION: Serum magnesium may have a protective role against aortic valve sclerosis, while both low and high levels of serum calcium could be risk factor for the condition. These serum micronutrients may be indications of cardiovascular disease risk prediction or prevention, and more research is required.

Tenapanor: A Phosphate Absorption Inhibitor for the Management of Hyperphosphatemia in Patients With Kidney Failure.

Because of increased risks of cardiovascular disease and death, patients with hyperphosphatemia receiving maintenance dialysis are advised to limit phosphorus consumption and are prescribed phosphate binders in an effort to better control serum phosphate concentrations. Because of large pill size, pill burden, and tolerability issues, phosphate binder adherence is relatively poor. On ingestion, phosphate is absorbed from the intestine via transcellular or paracellular transport. Data show that inhibiting sodium-hydrogen exchanger 3 modulates paracellular phosphate absorption (the predominant pathway in humans). Tenapanor is a first-in-class, minimally absorbed, phosphate absorption inhibitor that selectively inhibits sodium-hydrogen exchanger 3, with a mechanism distinct from, and complementary to, that of phosphate binders. In phase 3 and postregistrational studies, tenapanor conferred statistically significant and clinically meaningful reductions in serum phosphate in patients receiving maintenance dialysis with hyperphosphatemia. Here, we review the available preclinical and clinical data on the effects of tenapanor on controlling intestinal phosphate absorption.

High Serum Phosphate Is Associated with Cardiovascular Mortality and Subclinical Coronary Atherosclerosis: Systematic Review and Meta-Analysis.

(1) Background: Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. The aim of the study was to examine the existing published results of the association between elevated serum phosphate concentrations and cardiovascular mortality, along with the CVD incidence and subclinical coronary atherosclerosis, in primary prevention among non-selected samples of the general population. (2) Methods: A systematic review and meta-analysis were carried out using literature obtained from PubMed, SCOPUS, and the Web Of Science until March 2024 and following the PRISMA guidelines. Relevant information was extracted and presented. Random and fixed effects models were used to estimate the pooled odds ratio (OR) and hazard ratio (HR) with their 95% coefficient interval (CI), and I2 was used to assess heterogeneity. (3) Results: Twenty-five studies met our inclusion criteria and were included in the meta-analysis (11 cross-sectional and 14 cohort studies). For cardiovascular mortality, which included 7 cohort studies and 41,764 adults, the pooled HR was 1.44 (95% CIs 1.28, 1.61; I2 0%) when the highest versus the reference level of serum phosphate concentrations were compared. For CVDs, which included 8 cohort studies and 61,723 adults, the pooled HR was 1.12 (95% CIs 0.99, 1.27; I2 51%). For subclinical coronary atherosclerosis, which included 11 cross-sectional studies and 24,820 adults, the pooled OR was 1.44 (95% CIs 1.15, 1.79; I2 88%). (4) Conclusions: The highest serum phosphate concentrations were positively associated with a 44% increased risk of cardiovascular mortality and subclinical coronary atherosclerosis.

Exploring the Relationship Between Serum Phosphate Levels and Carotid Intima-Media Thickness in Chronic Kidney Disease Patients: A Correlational Analysis.

Background Compelling observational data suggest that heightened levels of fasting blood phosphate are linked to a higher likelihood of cardiovascular disease, spanning across both the general populace and individuals grappling with chronic kidney disease (CKD). This study aimed to explore the possible correlation between carotid intima-media thickness (CIMT) and blood phosphate levels among those afflicted with chronic renal dysfunction. Objective The primary goal of this study is to determine the potential association between blood phosphate levels and CIMT in patients with CKD. Methodology In the department of nephrology, prospective research was conducted among patients who had a history of CKD. A total of 30 patients were included, with 20 males and 10 females. Every case had a thorough physical examination and history. Every patient underwent a laboratory evaluation, which included measurements of the CIMT and renal function testing. At a distance of 1 cm from the carotid bulb, the CIMT was measured using B-mode ultrasonography. After compilation, the data were examined. Results The majority of the patients, according to this study, were male and over 50 years old. The Stage II patients in the study had a higher mean systolic blood pressure; however, the difference was not statistically significant. Patients with Stage V (D) disease exhibited higher diastolic blood pressure, but not statistically significant. An increase in the mean serum creatinine level that was statistically significant was linked to Stage V (D) renal disease. A higher mean blood urea was linked to Stage V (D) sickness; however, this relationship was not statistically significant. There was no statistical difference in the mean serum calcium levels between the different stages of renal disease. Higher mean blood phosphate levels were linked to Stage III renal disease, but not in a statistically meaningful way. Although it was higher in Stage IV kidney disease, the mean CIMT was not statistically significant between the stages of renal illness. Conclusions Although a positive correlation was shown, a direct relationship between serum phosphate levels was not established by this investigation. The severity of renal disease has been demonstrated to correlate with elevated serum phosphate levels.

Correlation between serum phosphate and all-cause mortality in critically ill patients with coronary heart disease accompanied by chronic kidney disease: a retrospective study using the MIMIC-IV database.

Background: The adverse clinical endpoints of cardiovascular and kidney diseases are correlated with increased serum phosphate levels. However, in critically ill patients with coronary heart disease (CHD) accompanied by chronic kidney disease (CKD), the prognostic value of serum phosphate remains unclear. Methods: Patients' medical records from the Medical Information Mart for Intensive Care IV database who had concomitant CKD and CHD were classified into four distinct groups in this large retrospective observational cohort study based on the quartiles of serum phosphate levels. Vital status and the duration of hospital and ICU stays within the short-term follow-up periods of 30 and 90 days constituted the primary outcomes. All-cause mortality in the intensive care unit (ICU) and hospital constituted the secondary outcomes. Further, the Cox proportional hazard and restricted cubic spline (RCS) regression models were employed to ascertain how serum phosphate levels correlated with the primary outcomes. In addition, the occurrence rate of the secondary outcomes across the four quartiles was determined utilizing the Kaplan-Meier method. Results: Among the total 3,557 patients (67.6% male) included, the hospital and ICU all-cause mortality rates were 14.6% and 10%, separately. Higher quartiles of serum phosphate concentrations were associated with shorter short-term survival rates, as shown by the Kaplan-Meier curves. Additionally, the Cox proportional hazards analysis illustrated that serum phosphate was independently linked to a higher death risk in the hospital [HR, 1.10 (95% CI: 1.03-1.18), P = 0.007] and ICU [HR, 1.14 (95% CI: 1.07-1.22), P < 0.001]. Lastly, the RCS regression models suggested a robust non-linear correlation between serum phosphate concentrations and death risk in the ICU and hospital (both P for non-linearity <0.001). Conclusions: The prognostic value of serum phosphate is significant in critically ill patients with CHD accompanied by CKD. Furthermore, serum phosphate is potentially valuable for identifying patients with this concomitant condition.

Assessing the predictive value of serum phosphate for short-term mortality in acute-on-chronic liver failure patients: An observational study at a non-transplant tertiary care centre.

Aim of the study: The gradual clinical worsening of acute-on-chronic liver failure (ACLF) leads to a high 28-day mortality rate. There are several prognostication scores for predicting early mortality in ACLF. Serum phosphate, which is the main component of adenosine tri-phosphate (ATP) synthesis, is utilized for liver synthetic functions, leading to subnormal or decreased serum phosphate levels. Hence more than normal levels of serum phosphate can be used as a marker of decreased liver cell reserve. Hence, we aimed to compare serum phosphate levels with available prognostic scores to assess mortality among ACLF patients. Material and methods: 100 consecutive ACLF patients according to the Asia Pacific Association for Study of the Liver (APASL) definition were studied. The baseline blood workups and determination of viral bio-markers, serum phosphate, and lactate levels on days 1, 3, and 7 were carried out and prospectively followed up, and the baseline serum phosphate levels were compared with the usual scores to predict the 28-day mortality. Results: CLIF-SOFA (accuracy 76-91%) followed by CLIF-C score (accuracy 73-84%) and AARC score (accuracy 70-85%) had the statistically significantly highest accuracy as compared with CTP, MELD, and MELD-Na on all three days. Serum phosphate values (accuracy 69-86%) on all three days were not better than the CLIF-SOFA score but better than all other prognostic scores on days 3 and 7. Conclusions: The high serum phosphate levels on day 3 with a value of more than 6.4 mg/dl showed almost comparable accuracy with CLIF-SOFA for screening short-term mortality. Hence serum phosphate measurement can be used as a simple bedside laboratory investigation to predict mortality in ACLF patients and early interventions in low-resource settings.

Effect of early serum phosphate disorder on in-hospital and 28-day mortality in sepsis patients: a retrospective study based on MIMIC-IV database.

BACKGROUND: This study aims to assess the influence of early serum phosphate fluctuation on the short-term prognosis of sepsis patients. METHODS: This retrospective study used the Medical Information Mart for Intensive Care IV database to analyze serum phosphate levels in sepsis patients within 3 days of ICU admission. According to the absolute value of delta serum phosphate (the maximum value minus the minimum value of serum phosphorus measured within three days), the patients were divided into four groups, 0-1.3, 1.4-2.0, 2.1-3.1, and ≥ 3.2 mg/dl. Meanwhile, the direction of delta serum phosphate was compared. With the serum phosphate change group of 0-1.3 mg/dl as the reference group, the relationship between delta serum phosphate and in-hospital mortality and 28-day mortality was analyzed by multivariate Logistics regression analysis. RESULTS: The study involved 1375 sepsis patients. Serum phosphate changes (0-1.3, 1.4-2.0, 2.1-3.1, and ≥ 3.2 mg/dl) correlated with in-hospital and 28-day mortality variations (p = 0.005, p = 0.008). Much higher serum phosphate fluctuation elevated in-hospital and 28-day mortality. Compared to the 0-1.3 mg/dl change group, adjusted odds ratios (OR) in other groups for in-hospital mortality were 1.25 (0.86-1.81), 1.28 (0.88-1.86), and 1.63 (1.10-2.43), and for 28-day mortality were 1.21 (0.86-1.72), 1.10 (0.77-1.57), and 1.49 (1.03-2.19). Under the trend of increasing serum phosphate, the ORs of in-hospital mortality and 28-day mortality in ≥ 3.2 mg/dl group were 2.52 and 2.01, respectively. CONCLUSION: In conclude, the delta serum phosphate ≥ 3.2 mg/dl was associated with in-hospital mortality and 28-day mortality in patients with sepsis.

Influencing factors of cardiac autonomic dysfunction in hemodialysis patients / 中华肾脏病杂志

Objective:To investigate the influencing factors of cardiac autonomic dysfunction in maintenance hemodialysis (MHD) patients by recording 48 h heart rate variability.Methods:It was a single-center cross-sectional study. MHD patients at the Hemodialysis Center of Peking University People's Hospital between October 1, 2021 and December 31, 2022 were enrolled in the study. These patients initiated hemodialysis for more than three months and were older than 18 years old, and patients with tachyarrhythmia, implanted cardiac pacemaker and the recording time less than 48 h were excluded. Demographic data, comorbidity, laboratory data, hemodialysis session data and heart rate variability were collected. Multivariate linear regression model was used to analyze the influencing factors for cardiac autonomic dysfunction in MHD patients.Results:A total of 110 patients were enrolled in the study, including 37 females (33.6%) and 36 diabetic patients (32.7%). The age of the patients was (57.8±14.8) years old, and the median dialysis vintage was 73.00(27.75±130.25) months. At baseline, the serum phosphate level was (1.6±0.4) mmol/L, and the N-terminal pro B-type natriuretic peptide (NT-proBNP) after ln transformed {ln[NT-proBNP(ng/L)]} was 8.4±1.2. The standard deviation of all normal R-R interval (SDNN) was (90.6±27.9) ms, ln[root mean square of successive differences in R-R interval (RMSSD, ms)] 3.2±0.8, ln[low frequency (ms 2)] 3.4±1.3, ln[high frequency (ms 2)] 3.1±1.4, and ln[low frequency/high frequency ratio] 0.28±0.64. After adjusting the age, coronary heart disease, diabetes, hemoglobin, serum phosphate and 25-hydroxy-vitamin D, serum natrium ( β=2.042, 95% CI 0.021–4.064, P=0.048) and ln[NT-proBNP (ng/L)] ( β=-7.027, 95% CI -12.247–-1.808, P=0.009) were independently correlated with SDNN (adjusted R2=0.218). Univariate linear regression model showed that diabetes was correlated with ln[low frequency(ms 2)] of MHD patients ( β=-0.659, 95% CI -1.171–-0.146, P=0.012), but in the multivariate linear regression model, significant correlation between diabetes and low frequency was not found. After adjusting the diabetes, coronary heart disease, dialysis vintage, hemoglobin, serum phosphate, serum albumin, pre-dialysis systolic blood pressure, post-dialysis systolic blood pressure, pre-dialysis diastolic blood pressure, increasing age ( β=-0.011, 95% CI -0.019–-0.003, P=0.007) and ln[NT-proBNP(ng/L)] ( β=-0.151, 95% CI -0.253–-0.048, P=0.004) were independently correlated with a decrease in the ln[low frequency/high frequency ratio]. In the multivariate linear regression model with ln[high frequency(ms 2)] or ln[RMSSD(ms)] as dependent variable, after adjusting the relevant factors, serum phosphate level was independently correlated with ln[RMSSD(ms)] ( β=-0.421, 95% CI -0.777–-0.065, P=0.021) or ln[high frequency(ms 2)] ( β=-0.752, 95% CI -1.325–-0.180, P=0.010). Conclusions:Hyperphosphatemia is an independent influencing factor of parasympathetic nervous system in MHD patients. Higher NT-proBNP is associated with lower SDNN and lower ratio of low frequency/high frequency, so serum phosphate control and volume control should be highlighted. Age is associated with autonomic dysfunction in MHD patients, so more attention should be paid to elder patients.

Association between serum phosphate and in-hospital mortality of patients with AECOPD: A retrospective analysis on eICU database.

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important adverse event in the development of chronic obstructive pulmonary disease (COPD). Hyperphosphatemia is associated with higher mortality in patients with multiple diseases. In this study, we aimed to determine the relationship between serum phosphate and the risk of in-hospital mortality in patients with AECOPD. Methods: In the present study, patients with AECOPD were enrolled in the electronic Intensive Care Unit Collaborative Research Database (eICU-CRD), and divided into three groups according to the tertiles of serum phosphate level. The primary outcome measure was all-cause in-hospital mortality. The association between serum phosphate level and in-hospital mortality was investigated using multivariate logistic regression analysis. Moreover, subgroup analysis was performed to explore whether the relationship was consistent among different subgroups. Results: A total of 1199 AECOPD patients were included in this study. Non-survivors had higher serum phosphate levels than survivors. All patients were classified into lowest tertile, median tertile, and highest tertile, respectively. Multivariate logistic regression analysis indicated that serum phosphate was positively associated with in-hospital mortality after adjusting for confounders. Moreover, there was a significant trend across tertiles when serum phosphate level was diverted as a categorical variable. In addition, subgroup analysis demonstrated that serum phosphate was consistently associated with a higher risk of in-hospital mortality in different subgroups. Conclusion: Higher serum phosphate was positively associated with the increased in-hospital mortality in patients with AECOPD. Hyperphosphatemia may be an underlying high-risk factor for in-hospital mortality owing to AECOPD.

Serum phosphate is associated with increased risk of bone fragility fractures in hemodialysis patients.

BACKGROUND: Bone fragility fractures are associated with high morbidity and mortality. This study analysed the association between the current biochemical parameters of CKD-MBD and bone fragility fractures in the COSMOS project. METHODS: COSMOS is a 3-year, multicentre, open cohort, prospective, observational study carried out in 6797 hemodialysis patients (227 centres from 20 European countries). The association of bone fragility fractures (outcome) with serum calcium, phosphate and PTH (exposure), was assessed using Standard Cox proportional hazards regression and Cox proportional hazards regression for recurrent events. Additional analyses were performed considering all-cause mortality as a competitive event for bone fragility fracture occurrence. Multivariable models were used in all strategies, with the fully adjusted model including a total of 24 variables. RESULTS: During a median follow-up of 24 months 252 (4%) patients experienced at least one bone fragility fracture (incident bone fragility fracture rate 28.5 per 1000 patient-years). In the fractured and non-fractured patients, the percentage of men was 43.7% and 61.4%, mean age 68.1 and 63.8 years and a haemodialysis vintage of 55.9 and 38.3 months respectively. Baseline serum phosphate > 6.1 mg/dL (reference value 4.3-6.1 mg/dL) was significantly associated with a higher bone fragility fracture risk in both regression models (HR: 1.53[95%CI: 1.10-2.13] and HR: 1.44[95%CI: 1.02-2.05]. The significant association persisted after competitive risk analysis (subHR: 1.42[95%CI: 1.02-1.98]) but the finding was not confirmed when serum phosphate was considered as a continuous variable. Baseline serum calcium showed no association with bone fragility fracture risk in any regression model. Baseline serum PTH > 800 pg/mL was significantly associated with a higher bone fragility fracture risk in both regression models, but the association disappeared after a competitive risk analysis. CONCLUSIONS: Hyperphosphatemia was independently and consistently associated with an increased bone fracture risk, suggesting serum phosphate could be a novel risk factor for bone fractures in hemodialysis patients.

Association between serum phosphate levels and anemia in non-dialysis patients with chronic kidney disease: a retrospective cross-sectional study from the Fuji City CKD Network.

BACKGROUND: Patients with chronic kidney disease (CKD) present high mortality and morbidity rates despite the availability of various therapies. Although CKD-mineral and bone disorder (MBD) and renal anemia are important factors in patients with CKD, only few studies have analyzed the relationship between them. Therefore, this study aimed to evaluate the relationship between CKD-MBD and anemia in patients with CKD who did not receive erythropoiesis-stimulating agent or iron therapies. METHODS: This retrospective cross-sectional study included patients with CKD aged ≥ 20 years with estimated glomerular filtration rate (eGFR) categories G2a to G5 who were referred to the Fuji City General Hospital between April 2018 and July 2019. The exclusion criterion was ongoing treatment for CKD-MBD and/or anemia. RESULTS: The data of 300 patients with CKD were analyzed in this study. The median age of patients was 71 (range, 56.5-79) years. The median eGFR was 34 (range, 20-48) mL/min/1.73 m2, and the mean hemoglobin (Hb) level was 12.7 g/dL (standard deviation, 2.3), which decreased as the CKD stage increased. In a multivariate linear regression analysis of anemia-related factors, including age, renal function (eGFR), nutritional status, inflammation, and iron dynamics (serum iron level, total iron-binding capacity, ferritin levels), the serum phosphate levels were significantly associated with the Hb levels (coefficient [95% confidence interval], -0.73 [-1.1, -0.35]; P < 0.001). Subgroup analysis revealed a robust association between serum phosphate levels and Hb levels in the low-ferritin (coefficient [95% confidence interval], -0.94 [-1.53, -0.35]; P = 0.002) and advanced CKD groups (coefficient [95% confidence interval], -0.89 [-1.37, -0.41]; P < 0.001). CONCLUSIONS: We found an association between high serum phosphate levels and low Hb levels in patients with CKD not receiving treatment for anemia. These results underscore the possibility of a mechanistic overlap between CKD-MBD and anemia.

The efficacy and safety of cuttlebone for lowering serum phosphate in patients with end-stage renal disease: a meta-analysis of randomized controlled trials.

Background: The efficacy of cuttlebone for treating hyperphosphatemia in patients with end-stage renal disease and its safety remained unclear. Methods: Randomized controlled trials comparing the efficacy of cuttlebone with conventional interventions were retrieved from MEDLINE, EMBASE, Cochrane Library, Airiti Library, and other major Chinese databases until 1 February 2023. The primary outcome was circulating phosphate concentration, while secondary outcomes included circulating calcium and intact parathyroid hormone levels, calcium-phosphorus product, and treatment-related side-effects. Results: Analysis of nine studies published between 2000 and 2019 including 726 participants showed a lower circulating phosphate concentration in the cuttlebone group than in controls [mean difference (MD) = -0.23, 95% CI: -0.39 to -0.06, p = 0.006, I2 = 94%, 726 patients] and a dose-dependent effect of cuttlebone against hyperphosphatemia. Therapeutic benefits were noted after both short-term (1-2 months) and long-term (3-6 months) treatments. Besides, patients receiving hemodialysis showed a better response to cuttlebone than those receiving peritoneal dialysis. There was no difference in circulating calcium level (mean difference = 0.03, 95% CI: -0.01 to 0.07, p = 0.17, I2 = 34%, 654 patients), while patients receiving cuttlebone showed lower circulating iPTH level and calcium-phosphorus product (MD = -43.63, 95% CI: -74.1 to -13.16, p = 0.005, I2 = 76%, 654 patients), (MD = -0.38, 95% CI: -0.38 to -0.01, p = 0.04, I2 = 83%, 520 patients). No difference in the risks of constipation, gastrointestinal discomfort, and elevated blood calcium was noted between the two groups. Conclusion: Compared with conventional phosphate-binding agents, cuttlebone more efficiently suppressed hyperphosphatemia with a dose-dependent effect. The limited number of included studies warrants further clinical investigations to verify our findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023396300.

Association between drinking water fluoride and the serum alkaline phosphatase and phosphate levels in pregnant women and newborn infants.

BACKGROUND: Endemic fluorosis (skeletal and dental) is a serious public health problem in many parts of the world, especially in India. Age, sex, dietary calcium (Ca), the hormonal status, the dose and duration of the fluoride intake, and renal efficiency in handling fluoride all influence fluoride metabolism. OBJECTIVES: The aim of the study was to evaluate the effect of the fluoride present in drinking water on the serum alkaline phosphatase (ALP) and phosphate levels in pregnant women and newborn infants. MATERIAL AND METHODS: In the present cross-sectional study, the participants were categorized into 2 groups based on a fluoride concentration in their drinking water: the low/optimum-fluoride group (<1 ppm); and the high-fluoride group (≥1 ppm). Each group was comprised of 90 pregnant women who were recruited from the hospital at the time of admission for delivery. Fluoride was measured in their drinking water, urine, maternal serum, and cord blood. The ALP and phosphate levels were measured in serum using a fully automated analyzer. RESULTS: The drinking water consumed by the pregnant women contained fluoride, which was significantly positively correlated with the urine and blood serum fluoride levels. There were significant differences in the ALP levels between the 2 groups in both maternal serum and cord blood. The level of phosphate in maternal serum was significantly higher in the high-fluoride group. The results of both simple and multivariate regression analyses revealed that the fluoride content in drinking water was significantly associated with the ALP level in cord blood and the phosphate level in maternal serum. CONCLUSIONS: The ALP levels were negatively associated with drinking water fluoride concentrations in both maternal serum and cord blood. The phosphate levels in maternal serum were positively associated with drinking water fluoride concentrations.

Long-term trajectories of bone metabolism parameters and bone mineral density (BMD) in obese patients treated with metabolic surgery: a real-world, retrospective study.

PURPOSE: Potential negative effects of metabolic surgery on skeletal integrity remain a concern, since long-term data of different surgical approaches are poor. This study aimed to describe changes in bone metabolism in subjects with obesity undergoing both Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). METHODS: A single center, retrospective, observational clinical study on real-world data was performed enrolling subjects undergoing metabolic surgery. RESULTS: 123 subjects were enrolled (males 31: females 92; ages 48.2 ± 7.9 years). All patients were evaluated until 16.9 ± 8.1 months after surgery, while a small group was evaluated up to 4.5 years. All patients were treated after surgery with calcium and vitamin D integration. Both calcium and phosphate serum levels significantly increased after metabolic surgery and remained stable during follow-up. These trends did not differ between RYGB and SG (p = 0.245). Ca/P ratio decreased after surgery compared to baseline (p < 0.001) and this decrease remained among follow-up visits. While 24-h urinary calcium remained stable across all visits, 24-h urinary phosphate showed lower levels after surgery (p = 0.014), also according to surgery technique. Parathyroid hormone decreased (p < 0.001) and both vitamin D (p < 0.001) and C-terminal telopeptide of type I collagen (p = 0.001) increased after surgery. CONCLUSION: We demonstrated that calcium and phosphorous metabolism shows slight modification even after several years since metabolic surgery, irrespective of calcium and vitamin D supplementation. This different set point is characterized by a phosphate serum levels increase, together with a persistent bone loss, suggesting that supplementation alone may not ensure the maintenance of bone health in these patients.

Dietary Strawberries Improve Serum Metabolites of Cardiometabolic Risks in Adults with Features of the Metabolic Syndrome in a Randomized Controlled Crossover Trial.

Dietary strawberries have been shown to improve cardiometabolic risks in multiple clinical trials. However, no studies have reported effects on serum metabolomic profiles that may identify the target pathways affected by strawberries as underlying mechanisms. We conducted a 14-week randomized, controlled crossover study in which participants with features of metabolic syndrome were assigned to one of the three arms for four weeks separated by a one-week washout period: control powder, 1 serving (low dose: 13 g strawberry powder/day), or 2.5 servings (high dose: 32 g strawberry powder/day). Blood samples, anthropometric measures, blood pressure, and dietary and physical activity data were collected at baseline and at the end of each four-week phase of intervention. Serum samples were analyzed for primary metabolites and complex lipids using different mass spectrometry methods. Mixed-model ANOVA was used to examine differences in the targeted metabolites between treatment phases, and LASSO logistic regression was used to examine differences in the untargeted metabolites at end of the strawberry intervention vs. the baseline. The findings revealed significant differences in the serum branched-chain amino acids valine and leucine following strawberry intervention (high dose) compared with the low-dose and control phases. Untargeted metabolomic profiles revealed several metabolites, including serum phosphate, benzoic acid, and hydroxyphenyl propionic acid, that represented improved energy-metabolism pathways, compliance measures, and microbial metabolism of strawberry polyphenols, respectively. Thus, dietary supplementation of strawberries significantly improves the serum metabolic profiles of cardiometabolic risks in adults.

Self-Administration of Burosumab in Children and Adults with X-Linked Hypophosphataemia in Two Open-Label, Single-Arm Clinical Studies.

INTRODUCTION: X-linked hypophosphataemia (XLH) is a rare, genetic renal phosphate-wasting disease, resulting from excess fibroblast growth factor 23 (FGF23) activity, which has a progressive and profound impact on patients throughout life. The monoclonal anti-FGF23 antibody, burosumab, is a subcutaneous injection indicated for the treatment of XLH in children and adults. Originally, burosumab was approved to be administered by a healthcare professional (HCP), but the option of self-administration would enable patient independence and easier access to treatment. Two open-label, single-arm clinical trials, conducted in Japan and Korea, have assessed the safety and efficacy of self-administration of burosumab in both children and adults with XLH. METHODS: In KRN23-003 (n = 15 children aged 1-12 years) and KRN23-004 (n = 5 children aged 3-13 years, n = 4 adults aged 21-65 years), children initially received 0.8 mg/kg of burosumab every 2 weeks and adults initially received 1.0 mg/kg of burosumab every 4 weeks. Self-administration was permitted from Week 4, and patients or carers were provided with training to inject correctly. RESULTS: In both trials, burosumab had an acceptable safety profile with mainly mild-to-moderate adverse events. Following self-administration, no patients reported serious treatment-emergent adverse events ≥ grade 3, injection-site reactions or hypersensitivity reactions related to burosumab. Serum phosphate and active vitamin D levels increased from baseline in children and adults. CONCLUSIONS: These results indicated that the efficacy and safety of burosumab when administered either by a carer or patient are similar to that when administered by an HCP and show that self-administration is a viable option for patients with XLH. TRIAL REGISTRATION NUMBERS: NCT03233126 and NCT04308096.

Association between admission serum phosphate and risk of acute kidney injury in critically ill patients with rhabdomyolysis: A retrospective study based on MIMIC-â ¢.

BACKGROUND: The incidence of acute kidney injury (AKI) is high in critically ill patients with rhabdomyolysis. Limited evidence was proved of the association between serum phosphate levels at intensive care unit (ICU) admission and the subsequent risk of AKI. Our study aims to assess if serum phosphate levels at admission were independently associated with AKI risk in these patients. METHODS: This study extracted and analyzed data from Medical Information Mart for Intensive Care-Ⅲ (MIMIC-Ⅲ, version1.4). Rhabdomyolysis was defined as a peak creatine kinase (CK) level higher than 1000 U/L. Serum phosphate was measured within the first day into the ICU and was categorized to 4 groups (<2.6, 2.6-3.4, 3.5-4.5, >4.5mg/dl). AKI was defined according to the Kidney Disease Improving Global Outcome (KDIGO) guidelines. Adjusted smoothing spline plots and multivariable logistic regressions were carried out to explode the association between serum phosphate and risk of AKI. Subgroup analyse was applied to verify the consistency of the association. RESULTS: Three hundred and twenty-one patients (68% male) diagnosed as rhabdomyolysis were eligible for this analysis. AKI occurred in 204 (64%) patients of total. Incidence of AKI with admission serum phosphate groups<2.6, 2.6-3.4, 3.5-4.5 and>4.5mg/dl were 53%, 57%, 68% and 76%, respectively. Smoothing spline curve showed that there was a positive curve between the elevated phosphate values and increasing risk of AKI, and there was no threshold saturation effect. In multivariable logistic regression, OR was 1.2 (95%CI 1.0-1.5, P=0.035, P trend=0.041) after adjusting confounders. Subgroup analyses proved the consistency of the relationship in these patients, possibly, except in the strata of potassium. CONCLUSION: In rhabdomyolysis patients admitted to ICU, serum phosphate levels at admission were independently associated with an increased risk of AKI. As phosphate levels rise, the risk of AKI increased.