***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Heart and coronary calcifications in hemodialysis patients are of very common occurrence and linked to cardiovascular events and mortality . Several studies have been published with similar results . Most of them were mainly cross-sectional and some of the prospect i ve protocol s were aim ed to evaluate the results of the control of altered biochemical parameters of mineral disturbances with special regard to serum calcium , phosphate and CaxP with the use of calcium containing and calcium free phosphate chelating agents . The aim of the present study was to evaluate in hemodialysis patients classic and some non classic risk factors as predictors of calcification changes after one year and to evaluate the impact of progression on survival . Methods 81 patients on hemodialysis were studied , with a wide age range and HD vintage . Several classic parameters and some less classic risk factors were studied like fetuin-A , CRP , 25-OHD and leptin . Calcifications , as Agatston scores , were evaluated with Multislice CT basally and after 12 - 18 months . Results Coronary artery calcifications were observed in 71 of 81 patients . Non parametric correlations between Agatston scores and Age , HD Age , PTH and CRP were significant . Delta increments of Agatston scores correlated also with serum calcium , CaxP , Fetuin-A , triglycerides and serum albumin . Logistic regression analysis showed Age , PTH and serum calcium as important predictors of Delta Agatston scores . LN transformation of the not normally distributed variables restricted the significant correlations to Age , BMI and CRP . Considering the Delta Agatston scores as dependent , significant predictors were Age , PTH and HDL . A strong association was found between basal calcification scores and Delta increment at one year . By logistic analysis , the one year increments in Agatston scores were found to be predictors of mortality .  Diabetic and hypertensive patients have significantly higher Delta scores . Conclusions Progression of calcification is of common occurrence , with special regard to elevated basal scores , and is predictive of survival . Higher predictive value of survival is linked to the one year increment of calcification scores . Some classic and non classic risk factors play an important role in progression . Some of them could be controlled with appropriate management with possible improvement of mortality BACKGROUND AND OBJECTIVES Hyperphosphatemia , vitamin D deficiency , hyperparathyroidism , and high serum fibroblast growth factor 23 ( FGF23 ) levels , when studied separately , were found to predict the progression of CKD . However , studies with simultaneous measurement of mineral bone disorder (MBD)-related factors were scarce . This study aim ed to identify factors predicting renal outcome independent of other factors . DESIGN , SETTING , PARTICIPANTS , & MEASUREMENTS This was a prospect i ve cohort study of 738 Japanese predialysis out patients in the nephrology departments of two hospitals . The outcome was defined as a doubling of serum creatinine or initiation of dialysis . RESULTS Mean estimated GFR ( eGFR ) was 35 ml/min per 1.73 m(2 ) . At enrollment , the increase in intact FGF23 with decreasing eGFR was the earliest among changes in MBD-related factors , followed by 1,25-dihydroxyvitamin D decrease , parathyroid hormone increase , and phosphate increase . During a median duration of 4.4 years , 213 patients reached the endpoint . In a multivariable Cox model , high FGF23 and low 25-hydroxyvitamin D ( 25D ) levels were the only MBD-related factors associated with a higher risk of renal endpoint ( adjusted hazard ratio [ 95 % confidence interval ] per unit change of log FGF23 and 10 ng/ml of 25D : 1.83 [ 1.28 - 2.61 ] and 0.61 [ 0.41 - 0.90 ] , respectively ) . There was no significant interaction between 25D and FGF23 ( P=0.11 ) .  Active vitamin D therapy , serum phosphate , 1,25-dihydroxyvitamin D , and parathyroid hormone levels were not related to the renal endpoint . Treating death as a competing risk or multiple imputation for missing values yielded similar results . CONCLUSIONS Combined use of two markers is useful for the risk stratification of renal outcome Background — Patients with kidney disease have disordered bone and mineral metabolism , including elevated serum concentrations of fibroblast growth factor-23 ( FGF23 ) . These elevated concentrations are associated with cardiovascular and all-cause mortality . The objective was to determine the effects of the calcimimetic cinacalcet ( versus placebo ) on reducing serum FGF23 and whether changes in FGF23 are associated with death and cardiovascular events . Methods and Results — This was a secondary analysis of a r and omized clinical trial comparing cinacalcet to placebo in addition to conventional therapy ( phosphate binders/vitamin D ) in patients receiving hemodialysis with secondary hyperparathyroidism ( intact parathyroid hormone ≥300 pg/mL ) . The primary study end point was time to death or a first nonfatal cardiovascular event ( myocardial infa rct ion , hospitalization for angina , heart failure , or a peripheral vascular event ) . This analysis included 2985 patients ( 77 % of r and omized ) with serum sample s at baseline and 2602 patients ( 67 % ) with sample s at both baseline and week 20 . The results demonstrated that a significantly larger proportion of patients r and omized to cinacalcet had ≥30 % ( 68 % versus 28 % ) reductions in FGF23 . Among patients r and omized to cinacalcet , a ≥30 % reduction in FGF23 between baseline and week 20 was associated with a nominally significant reduction in the primary composite end point ( relative hazard , 0.82 ; 95 % confidence interval , 0.69–0.98 ) , cardiovascular mortality ( relative hazard , 0.66 ; 95 % confidence interval , 0.50–0.87 ) , sudden cardiac death ( relative hazard , 0.57 ; 95 % confidence interval , 0.37–0.86 ) , and heart failure ( relative hazard , 0.69 ; 95 % confidence interval , 0.48–0.99 ) . Conclusions — Treatment with cinacalcet significantly lowers serum FGF23 . Treatment-induced reductions in serum FGF23 are associated with lower rates of cardiovascular death and major cardiovascular events . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT00345839 BACKGROUND In chronic kidney disease stage 5D , diagnostic usefulness of bone mineral density ( BMD ) in predicting fracture has not been established because of variable results in previous studies . The reason for this may be the heterogeneity of underlying pathogenesis of the fracture . METHODS  BMD was measured annually and serum biochemistry monthly for 485 hemodialyzed patients from April 2003 to March 2008 , and all fractures were recorded . RESULTS Forty-six new episodes of any type of fracture and 29 cases of prevalent spine fracture were recorded . Serum bone-specific alkaline phosphatase ( b-AP ) was a very useful surrogate marker for any type of incident fracture risk [ area under curve ( AUC ) = 0.766 , P < 0.0001 ] . A significantly greater risk of any type of incident fracture was associated with parathyroid hormone ( PTH ) levels either < 150 pg/mL [ hazard ratio ( HR ) = 3.47 , P < 0.01 ] or > 300 pg/mL ( HR = 5.88 , P < 0.0001 ) compared with 150 - 300 pg/mL. Receiver-operating characteristic analysis demonstrated a significant predictive power for incident of any type of fracture by BMD at the total hip ( AUC = 0.760 , P < 0.0001 ) and other hip regions in females in the lower PTH group ( PTH < 204 pg/mL ) . BMDs at every site but whole body or lumbar spine had significant power to discriminate prevalent spine fracture regardless of gender or PTH . CONCLUSIONS Hemodialyzed patients with low or high PTH or increased b-AP had a high fracture risk . BMD by Dual Energy X-ray Absorptiometry ( DEXA ) , especially at the total hip region , was useful to predict any type of incident of fracture for females with low PTH or to discriminate prevalent spine fracture for every patient BACKGROUND AND OBJECTIVES Higher phosphate is associated with mortality in dialysis patients but few prospect i ve studies assess this in nondialysis patients managed in an outpatient nephrology clinic . This prospect i ve longitudinal study examined whether phosphate level was associated with death in a referred population . DESIGN , SETTING , PARTICIPANTS & MEASUREMENTS Patients ( 1203 ) of nondialysis chronic kidney disease ( CKD ) in the Chronic Renal Insufficiency St and ards Implementation Study were assessed .  Survival analyses were performed for quartiles of baseline phosphate relative to GFR , 12-month time-averaged phosphate , and baseline phosphate according to published phosphate targets . RESULTS  Mean ( SD ) eGFR was 32 ( 15 ) ml/min per 1.73 m(2 ) , age 64 ( 14 ) years , and phosphate 1.2 ( 0.30 ) mmol/L. Cox multivariate adjusted regression in CKD stages 3 to 4 patients showed an increased risk of all-cause and cardiovascular mortality in the highest quartile compared with that in the lowest quartile of phosphate . No association was found in CKD stage 5 patients . Patients who had values above recommended targets for phosphate control had increased risk of all-cause and cardiovascular death compared with patients below target . The highest quartile compared with the lowest quartile of 12-month time-averaged phosphate was associated with an increased risk of mortality . CONCLUSIONS In CKD stages 3 to 4 patients , higher phosphate was associated with a stepwise increase in mortality . As phosphate levels below published targets ( as opposed to within them ) are associated with better survival , guidelines for phosphate in nondialysis CKD patients should be re-examined . Intervention trials are required to determine whether lowering phosphate will improve survival Background Serum phosphate is a known risk factor for cardiovascular events and mortality in people with chronic kidney disease ( CKD ) , however data on the association of these outcomes with serum phosphate in the general population are scarce . We investigate this relationship in people with and without CKD in a large community-based population . Methods Three groups from an adult cohort of the Quality Improvement in Chronic Kidney Disease ( QICKD ) cluster r and omised trial ( IS RCT N56023731 ) were followed over a period of 2.5 years : people with normal renal function ( N = 24,184 ) , people with CKD stages 1–2 ( N = 20,356 ) , and people with CKD stages 3–5 ( N = 13,292 ) . We used a multilevel logistic regression model to determine the association between serum phosphate , in these groups , and a composite outcome of all-cause mortality , cardiovascular events , and advanced coronary artery disease . We adjusted for known cardiovascular risk factors . Findings Higher phosphate levels were found to correlate with increased cardiovascular risk . In people with normal renal function and CKD stages 1–2 , Phosphate levels between 1.25 and 1.50 mmol/l were associated with increased cardiovascular events ; odds ratio ( OR ) 1.36 ( 95 % CI 1.06–1.74 ; p = 0.016 ) in people with normal renal function and OR 1.40 ( 95 % CI 1.09–1.81 ; p = 0.010 ) in people with CKD stages 1–2 . Hypophosphatemia ( < 0.75 mmol/l ) was associated with fewer cardiovascular events in people with normal renal function ; OR 0.59 ( 95 % CI 0.36–0.97 ; p = 0.049 ) . In people with CKD stages 3–5 , hyperphosphatemia ( > 1.50 mmol/l ) was associated with increased cardiovascular risk ; OR 2.34 ( 95 % CI 1.64–3.32 ; p<0.001 ) . Other phosphate ranges were not found to have a significant impact on cardiovascular events in people with CKD stages 3–5 . Conclusions Serum phosphate is associated with cardiovascular events in people with and without CKD . Further research is required to determine the mechanisms underlying these associations BACKGROUND The management of chronic kidney disease-mineral and bone disorder requires the assessment of bone turnover , which most often is based on parathyroid hormone ( PTH ) concentration , the utility of which remains controversial . STUDY DESIGN Cross-sectional retrospective diagnostic test study . SETTING & PARTICIPANTS 492 dialysis patients from Brazil , Portugal , Turkey , and Venezuela with prior bone biopsy and stored ( -20 ° C ) serum .  IN 
    Output:
    
However , the studies did not show consistent beneficial effects of osteoporosis medications on BMD .
In conclusion , DXA BMD assessment is reasonable if low or decreasing BMD will lead to additional interventions to reduce falls or recommendations for use of osteoporosis medications .
The analysis underscored the importance of potential interactions among components of CKDMBD in terms of risk prediction for death or cardiovascular events .
High- quality evidence now links high phosphate concentrations with mortality among patients with CKD stage G3a to G5 and transplant recipients ( 1928 ) .
However , there is still a lack of data from clinical trials showing that therapeutic approaches to decreasing serum phosphate levels improve patient-centered outcomes .
The 2009 guideline suggested maintenance of normal serum phosphate levels for patients with CKD stages G3a to G4 .
Most studies found phosphate to be consistently associated with excess mortality at levels above and below the limits of normal but not in the normal range .