***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 . Management of anemia is an important factor in the care of patients with chronic kidney disease as the anemic state can confer significant morbidity and mortality . Posttransplantation anemia ( PTA ) has received comparatively less attention in the literature , and the prevalence and predictors of PTA vary between different studies . The purpose of this study was to investigate a large posttransplant population from 3 centres in the UK to eluci date the point prevalence of PTA , its determinants and the use of erythropoiesis stimulating agents ( ESA ) in these patients . Methods . All adult patients with functioning renal transplants and attending renal transplant out patients at Guy ’s , King ’s College , or St. Helier Hospitals , London , as of 31/12/2004 who had a valid hemoglobin in the previous 3 months , and who were more than 3 months postengraftment , were identified . Patients ’ notes and electronic patient records were obtained and a detailed cross-sectional clinical and biochemical data base was constructed . The data were analyzed for the point prevalence of PTA , the prevalence of ESA use and for determinants of hemoglobin . The WHO criteria were used to define anemia and all patients on treatment with an ESA was classified as anemic irrespective of hemoglobin . Results . A total of 1,511 ( 947 male ) patients were studied . Mean age was 48.1±13.7 years with no difference between the sexes . Mean time posttransplantation  was 8.5±7.2 years and mean estimated MDRD GFR was 47.6±18.9 ml/min with a higher GFR in males ( 49.9±19.0 v 43.8±18.0 mL/min , P<0.0001 ) . Mean hemoglobin in the studied population was 12.9±1.6 g/dl with a significantly higher level among males than females ( mean 13.3±1.6 v 12.3±1.4 g/dl , P<0.0001 ) . The prevalence of anemia was 45.6 % with a prevalence of 44.1 % among males and 48.1 % amongst females . Severe anemia was present in 50 subjects ( 3.3 % of the total cohort ) . One hundred and forty-five patients ( 9.6 % of the entire cohort ) were being treated with an ESA . Of these subjects , 41 did not meet WHO criteria for the definition of anemia . After multiple regression analyses , age , female sex , renal function and to a lesser extent serum ferritin and therapy with angiotensin converting enzyme inhibitors/angiotensin II receptor blockers ( both negatively associated ) were predictive of hemoglobin . Conclusions . The prevalence of anemia  posttransplantation was high while comparatively few patients were being treated with erythropoiesis stimulating agents . The strongest predictors of hemoglobin in this cohort of patients were age , female sex and allograft function . Medical therapy with MMF and sirolimus was associated with a high prevalence of anemia but this was likely to be the result of poorer graft function in these subjects who mostly had chronic allograft nephropathy . A large interventional prospect i ve study with valid control groups is now needed to assess the long-term contributions of clinical and biochemical factors of renal function and to eluci date the effects of therapy on outcome Cardiovascular disease ( CVD ) is the major cause of death in renal transplant recipients ( RTR ) . Several cohort studies have examined CVD in RTR , but none have addressed the development of congestive heart failure ( CHF ) . CHF would hypothetically be a frequent and prognostically important event in RTR . A retrolective cohort study was , therefore , conducted in two Canadian centers to describe the incidence , risk factors for , and interrelationships between de novo CHF , de novo ischemic heart disease ( IHD ) , and mortality in 638 consecutive adult RTR who were free of cardiac disease at 1 yr posttransplant . Detailed clinic and hospital records were available for 99 % of patients . Median follow-up was 7 yr ( range , 1 to 28 yr ) . De novo CHF occurred as frequently as de novo IHD ( 1.26 versus 1.22 events/100 patient-years , respectively ) and appeared to carry a similar prognosis ( relative risk for death , 1.78 [ confidence interval , 1.21 to 2.61 ] for CHF versus 1.50 [ 1.05 to 2.13 ] for IHD ) . The incidence of CHF was considerably higher than that in the Framingham cohort , whereas the incidence of IHD was not , suggesting that renal transplantation might correspond more to a state of " accelerated heart failure " than to " accelerated atherosclerosis . " Age , diabetes , gender , BP , and anemia were identified as independent risk factors for de novo CHF , whereas age , diabetes , gender , BP , and rejection were independent risk factors for de novo IHD . Optimal strategies for treatment of BP and anemia in RTR will need to be determined in r and omized controlled trials BACKGROUND Diabetic nephropathy is the leading cause of end-stage renal disease ( ESRD ) . Anemia is common in diabetics with nephropathy ; however , the impact of anemia on progression to ESRD has not been carefully examined . METHODS We studied the relationship between baseline hemoglobin concentration ( Hb ) and progression of diabetic nephropathy to ESRD  in 1513 participants enrolled in Reduction in Endpoints in NIDDM with the Angiotensin II Antagonist Losartan study and followed for an average of 3.4 years . Multivariate Cox proportional hazards models were used to analyze the relationship between Hb and ESRD , after adjusting for predictors for ESRD . Analyses were performed with Hb stratified by quartile : first quartile < 11.3 g/dL , second quartile 11.3 to 12.5 g/dL , third quartile 12.6 to 13.8 g/dL , and fourth quartile > /=13.8 g/dL ( reference ) and as a continuous variable . RESULTS Baseline hemoglobin concentration was correlated with subsequent development of ESRD . After adjustment for predictors of ESRD , the hazard ratios for the first , second , and third Hb quartiles were 1.99 ( 95 % CI , 1.34 - 2.95 ) , 1.61 ( 95 % CI 1.08 - 2.41 ) , and 1.87 ( 95 % CI 1.25 - 2.80 ) . With hemoglobin as a continuous variable , the adjusted hazard ratio was 0.90 ( 95 % CI 0.84 - 0.96 , P= 0.0013 ) . The average increase in adjusted relative risk was 11 % for each 1 g/dL decrease in hemoglobin concentration . CONCLUSION Our data suggest that even mild anemia , Hb < 13.8 g/dL increases risk for progression to ESRD . Hemoglobin is an independent risk factor for progression of nephropathy to ESRD in type 2 diabetes Background . It remains unclear whether low hemoglobin levels are associated with increased mortality or graft loss  after renal transplantation . This study assessed the relationship of hemoglobin levels with patient and graft survival in 3859 patients with functioning renal transplants more than 6-months posttransplantation . Methods . Detailed data was prospect ively collected as part of the pharmacovigilance Long Term Efficacy and Safety Surveillance project . Results . Lower hemoglobin levels were associated with graft loss on multivariate analysis adjusted for demographic characteristics , comorbidity , and biochemical variables ; lower hemoglobin was associated with mortality on univariate , but not adjusted analysis ; hemoglobin variability was associated with mortality and graft loss on univariate , but not multivariate analysis . Older recipient age , lower serum albumin , raised urea , increased comorbidity ( Charlson Index ) , and angiotensin-converting enzyme inhibitor (ACEi)/angiotensin II receptor blocker ( ARB ) non-use were also associated with mortality . Younger recipients , male recipients and those with lower serum albumin , lower body mass index , higher systolic blood pressure , and impaired allograft function experienced higher graft failure rates . Conclusions . This study suggests that full correction of hemoglobin levels to improve mortality in renal transplant recipients is unjustified ; further study is required to assess the effect of hemoglobin correction in delaying graft failure . It also highlights other nonimmunologic risk factors for adverse outcomes in renal transplant recipients BACKGROUND Recent data suggests that erythropoietin therapy may actually retard the progression of chronic kidney disease ( CKD ) . Transplant recipients with evidence of chronic allograft dysfunction could respond in a similar manner to erythropoietin . METHODS We evaluated 166 individuals who initiated erythropoietin therapy after at least 18 days of transplant function . One hundred and nine individuals received erythropoietin between days 18 and 294 of transplant function ( group 1-early epoietin alfa ) while 57 individuals received erythropoietin on or after day 294 of transplant function ( group 2-late epoietin alfa ) . The slope of serum creatinine ( Scr ) ( Deltaslope Scr ) prior to and following the start of erythropoietin therapy and calculated glomerular filtration rates ( GFR ) were used to assess renal function over time . RESULTS The average haematocrit rose 6.6 % in group 1 patients and 2.1 % in group 2 patients during the first 100 days of erythropoietin therapy . The Deltaslope Scr was not significantly altered in group 1 patients . However , for group 2 individuals who continued to have graft function ( n=35 ) , the Deltaslope Scr became negative during erythropoietin treatment . This indicated a deceleration in the rate of loss of renal function ( day 200 Deltaslope Scr -0.0033 , P=0.00091 ; day 300 Deltaslope Scr -0.0014 , P=0.05 ; day 400 Deltaslope Scr -0.0066 , N.S. , P=0.066 ) . GFR remained stable in both cohorts . Finally , group 2-late epoietin alfa patients treated with erythropoietin demonstrated a marked trend towards longer graft survival than a group of similar control patients ( N.S. , P=0.064 ) . CONCLUSIONS The data in a group of renal transplant recipients with chronic allograft dysfunction reinforce data from the CKD realm suggesting that erythropoietin may be of benefit in slowing the rate of loss of function over time . However , this renal response is not evident in all patients . Prospect i ve studies of erythropoietin or erythropoietin-like medications are warranted in this population to better discriminate those who may respond well to administration of these drugs BACKGROUND Erythropoietin is known to improve outcomes in patients with anemia from chronic renal disease . However , there is uncertainty about the optimal timing of initiation of erythropoietin treatment in predialysis patients with non-severe anemia . METHODS We conducted a r and omized controlled trial of early versus deferred initiation of erythropoietin in nondiabetic predialysis patients with serum creatinine 2 to 6 mg/dL and hemoglobin 9 to 11.6 g/dL. The early treatment arm was immediately started on 50 U/kg/wk of erythropoietin alpha with appropriate titration aim ing for hemoglobin of > or = 13 g/dL. The deferred treatment arm would start erythropoietin only when hemoglobin decreased to < 9 g/dL. The primary end point was a composite of doubling of creatinine , renal replacement , or death . RESULTS Eighty-eight patients were r and omized ( early treatment N= 45 , deferred treatment N= 43 ) and followed for a median of 22.5 months . During follow-up , 13 versus 23 patients reached the primary end point in the two arms , respectively ( log-rank P= 0.0078 ) . The relative hazard for reaching an end point was 0.42 ( P= 0.012 ) . Adjusting for baseline serum creatinine , the adjusted relative hazard was 0.37 ( P= 0.004 ) , while the risk increased 2.23-fold ( P < 0.001 ) per 1 mg/dL higher creatinine at baseline . The benefit was similar regardless of the baseline hemoglobin and proteinuria . No patients had any severe adverse events . CONCLUSION Early initiation of erythropoietin in predialysis patients with non-severe anemia significantly slows the progression of renal disease and delays the initiation of renal replacement therapy Background Anemia is a common complication in posttransplant patients ( posttransplant anemia : PTA ) . We tested the hypothesis that targeting hemoglobin ( Hb ) over 13.3 g/dl by administration of recombinant human erythropoietin ( rHuEPO-ad ) has positive impact on quality of life ( QOL ) . Methods Twenty-four patients , whose initial Hb and estimated glomerular filtration rate ( eGFR ) were 10.5 ± 0.2 g/dl and 48.5 ± 2.7 ml/(min  
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This meta- analysis reveals that the association between PTA and DPWFG varies with PTA definition and adjustment for confounders .
In all sub-meta-analyses , PTA was significantly associated with DCGL