1.
Association between calcium-phosphorus balance and adolescent idiopathic scoliosis: A meta-analysis.
Zhu, Q, Chen, J, Chen, C, Wang, H, Yang, S
Acta orthopaedica et traumatologica turcica. 2019;(6):468-473
Abstract
STUDY DESIGN A systematic review and meta-analysis. OBJECTIVE The objective of this meta-analysis was to evaluate the association between calcium-phosphorus balance and adolescent idiopathic scoliosis (AIS). METHODS Databases, including PubMed, OVID database, Web of Science, CBM database and CNKI database were searched for the relevant case control studies and cross-sectional studies. Two authors selected studies and extracted data independently. Data analysis was performed by Review Manager Software 5.0. Subgroup analysis was performed on the serum level of vitamin D according to gender and menstruation. RESULTS Five studies were included, with a total of 646 cases of AIS and 791 controls. AIS group had a lower serum level of vitamin D compared to control group [MD = -6.74, 95% CI (-9.47, -4.00)]. Gender and menstruation condition were thought to have no effect on the primary outcome of vitamin D level by subgroup analysis [MD = -5.97, 95% CI (7.61, -4.34)]. The AIS group had a lower calcium level [SMD= -0.77, 95% CI (-1.51, -0.02)] and calcitonin level compared to control group. There was no statistical difference in phosphorus level [SMD=0.5, 95% CI (-0.46, 0.57)] and parathyroid hormone level [SMD = -0.11, 95% CI (-0.54, -0.31)]. Meanwhile, the observational indexes, including serum levels of calcium, phosphorus, parathyroid hormone and calcitonin were within normal limits. CONCLUSION Vitamin D deficiency may be involved in the pathogenesis of AIS by influencing the regulation of calcium-phosphors metabolism on human bone. Therefore, we suggest to screen vitamin D level in AIS patients. LEVEL OF EVIDENCE Level III, Therapeutic Study.
2.
Phosphate binders for preventing and treating chronic kidney disease-mineral and bone disorder (CKD-MBD).
Ruospo, M, Palmer, SC, Natale, P, Craig, JC, Vecchio, M, Elder, GJ, Strippoli, GF
The Cochrane database of systematic reviews. 2018;(8):CD006023
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Abstract
BACKGROUND Phosphate binders are used to reduce positive phosphate balance and to lower serum phosphate levels for people with chronic kidney disease (CKD) with the aim to prevent progression of chronic kidney disease-mineral and bone disorder (CKD-MBD). This is an update of a review first published in 2011. OBJECTIVES The aim of this review was to assess the benefits and harms of phosphate binders for people with CKD with particular reference to relevant biochemical end-points, musculoskeletal and cardiovascular morbidity, hospitalisation, and death. SEARCH METHODS We searched the Cochrane Kidney and Transplant Register of Studies up to 12 July 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA We included randomised controlled trials (RCTs) or quasi-RCTs of adults with CKD of any GFR category comparing a phosphate binder to another phosphate binder, placebo or usual care to lower serum phosphate. Outcomes included all-cause and cardiovascular death, myocardial infarction, stroke, adverse events, vascular calcification and bone fracture, and surrogates for such outcomes including serum phosphate, parathyroid hormone (PTH), and FGF23. DATA COLLECTION AND ANALYSIS Two authors independently selected studies for inclusion and extracted study data. We applied the Cochrane 'Risk of Bias' tool and used the GRADE process to assess evidence certainty. We estimated treatment effects using random-effects meta-analysis. Results were expressed as risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI) or mean differences (MD) or standardised MD (SMD) for continuous outcomes. MAIN RESULTS We included 104 studies involving 13,744 adults. Sixty-nine new studies were added to this 2018 update.Most placebo or usual care controlled studies were among participants with CKD G2 to G5 not requiring dialysis (15/25 studies involving 1467 participants) while most head to head studies involved participants with CKD G5D treated with dialysis (74/81 studies involving 10,364 participants). Overall, seven studies compared sevelamer with placebo or usual care (667 participants), seven compared lanthanum to placebo or usual care (515 participants), three compared iron to placebo or usual care (422 participants), and four compared calcium to placebo or usual care (278 participants). Thirty studies compared sevelamer to calcium (5424 participants), and fourteen studies compared lanthanum to calcium (1690 participants). No study compared iron-based binders to calcium. The remaining studies evaluated comparisons between sevelamer (hydrochloride or carbonate), sevelamer plus calcium, lanthanum, iron (ferric citrate, sucroferric oxyhydroxide, stabilised polynuclear iron(III)-oxyhydroxide), calcium (acetate, ketoglutarate, carbonate), bixalomer, colestilan, magnesium (carbonate), magnesium plus calcium, aluminium hydroxide, sucralfate, the inhibitor of phosphate absorption nicotinamide, placebo, or usual care without binder. In 82 studies, treatment was evaluated among adults with CKD G5D treated with haemodialysis or peritoneal dialysis, while in 22 studies, treatment was evaluated among participants with CKD G2 to G5. The duration of study follow-up ranged from 8 weeks to 36 months (median 3.7 months). The sample size ranged from 8 to 2103 participants (median 69). The mean age ranged between 42.6 and 68.9 years.Random sequence generation and allocation concealment were low risk in 25 and 15 studies, respectively. Twenty-seven studies reported low risk methods for blinding of participants, investigators, and outcome assessors. Thirty-one studies were at low risk of attrition bias and 69 studies were at low risk of selective reporting bias.In CKD G2 to G5, compared with placebo or usual care, sevelamer, lanthanum, iron and calcium-based phosphate binders had uncertain or inestimable effects on death (all causes), cardiovascular death, myocardial infarction, stroke, fracture, or coronary artery calcification. Sevelamer may lead to constipation (RR 6.92, CI 2.24 to 21.4; low certainty) and lanthanum (RR 2.98, CI 1.21 to 7.30, moderate certainty) and iron-based binders (RR 2.66, CI 1.15 to 6.12, moderate certainty) probably increased constipation compared with placebo or usual care. Lanthanum may result in vomiting (RR 3.72, CI 1.36 to 10.18, low certainty). Iron-based binders probably result in diarrhoea (RR 2.81, CI 1.18 to 6.68, high certainty), while the risks of other adverse events for all binders were uncertain.In CKD G5D sevelamer may lead to lower death (all causes) (RR 0.53, CI 0.30 to 0.91, low certainty) and induce less hypercalcaemia (RR 0.30, CI 0.20 to 0.43, low certainty) when compared with calcium-based binders, and has uncertain or inestimable effects on cardiovascular death, myocardial infarction, stroke, fracture, or coronary artery calcification. The finding of lower death with sevelamer compared with calcium was present when the analysis was restricted to studies at low risk of bias (RR 0.50, CI 0.32 to 0.77). In absolute terms, sevelamer may lower risk of death (all causes) from 210 per 1000 to 105 per 1000 over a follow-up of up to 36 months, compared to calcium-based binders. Compared with calcium-based binders, lanthanum had uncertain effects with respect to all-cause or cardiovascular death, myocardial infarction, stroke, fracture, or coronary artery calcification and probably had reduced risks of treatment-related hypercalcaemia (RR 0.16, CI 0.06 to 0.43, low certainty). There were no head-to-head studies of iron-based binders compared with calcium. The paucity of placebo-controlled studies in CKD G5D has led to uncertainty about the effects of phosphate binders on patient-important outcomes compared with placebo.It is uncertain whether the effects of binders on clinically-relevant outcomes were different for patients who were and were not treated with dialysis in subgroup analyses. AUTHORS' CONCLUSIONS In studies of adults with CKD G5D treated with dialysis, sevelamer may lower death (all causes) compared to calcium-based binders and incur less treatment-related hypercalcaemia, while we found no clinically important benefits of any phosphate binder on cardiovascular death, myocardial infarction, stroke, fracture or coronary artery calcification. The effects of binders on patient-important outcomes compared to placebo are uncertain. In patients with CKD G2 to G5, the effects of sevelamer, lanthanum, and iron-based phosphate binders on cardiovascular, vascular calcification, and bone outcomes compared to placebo or usual care, are also uncertain and they may incur constipation, while iron-based binders may lead to diarrhoea.
3.
Calcium and Phosphate Metabolism, Blood Lipids and Intestinal Sterols in Human Intervention Studies Using Different Sources of Phosphate as Supplements-Pooled Results and Literature Search.
Trautvetter, U, Ditscheid, B, Jahreis, G, Glei, M
Nutrients. 2018;(7)
Abstract
Phosphates are associated with negative physiological effects. The objectives of this publication were to compare differential effects of supplementation with calcium phosphate or phosphate alone in healthy humans. Four adult human studies were conducted with pentacalcium hydroxy-trisphosphate supplementation (CaP; 90 subjects) and their data were pooled for assessment. For literature search; PubMed and ISI Web of Knowledge were used and 21 items were assigned to three main topics. The pooled study results show that following CaP supplementation, faecal calcium and phosphorus and urinary calcium were increased, blood lipids were positively modulated, and faecal bile acids were increased, as compared with placebo. The literature search reveals that following calcium phosphate supplementation, urinary calcium was increased. Following solely phosphate supplementation, urinary phosphorus was increased and urinary calcium was decreased. Postprandial calcium concentrations were increased following calcium phosphate supplementation. Postprandial phosphate concentrations were increased following solely phosphate supplementation. Calcium phosphate supplementation resulted in rather positively modulated blood lipids and gut-related parameters. The presented results show the relevance to distinguish between calcium phosphate and solely phosphate supplementations, and the importance of a balanced calcium and phosphorus intake.
4.
Nutrient-limited conditions determine the responses of foliar nitrogen and phosphorus stoichiometry to nitrogen addition: A global meta-analysis.
You, C, Wu, F, Yang, W, Xu, Z, Tan, B, Yue, K, Ni, X
Environmental pollution (Barking, Essex : 1987). 2018;:740-749
Abstract
To test the hypothesis that nutrient-limited conditions can determine the responses of nitrogen (N) and phosphorus (P) stoichiometry to N addition, a meta-analysis was conducted to identify the different responses of foliar N and P concentrations and N-to-P ratios to N addition under N limitation, N and P co-limitation and P limitation. N addition increased the foliar N-to-P ratios and N concentrations by 46.2% and 30.2%, respectively, under N limitation, by 18.7% and 19.7% under N and P co-limitation, and by 4.7% and 12.9% under P limitation. However, different responses of foliar P concentrations to N addition were observed under different nutrient limitations, and negative, positive, and neutral effects on P concentrations were observed under N limitation, P limitation and N and P co-limitation, respectively. Generally, the effects of N addition on N-to-P ratios and N concentrations in herbaceous plants were dramatically larger than those in woody plants (with the exception of the N-to-P ratio under N limitation), but the opposite situation was true for P concentrations. The changes in N-to-P ratios were closely correlated with the changes in N and P concentrations, indicating that the changes in both N and P concentrations due to N addition can drive N and P stoichiometry, but the relative sizes of the contributions of N and P varied greatly with different nutrient limitations. Specifically, the changes in N-to-P ratios may indicate a minimum threshold, which is consistent with the homeostatic mechanism. In brief, increasing N deposition may aggravate P limitation under N-limited conditions but improve P limitation under P-limited conditions. The findings highlight the importance of nutrient-limited conditions in the stoichiometric response to N addition, thereby advancing our ability to predict global plant growth with increasing N deposition in the future.