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Biomedical subjects

Adeera Levin

Publications and source records attributed to Adeera Levin.

At least 37 records · Page 2Linked to original sources
PubMed2005

Outcomes after percutaneous coronary interventions in patients with CKD: improved outcome in the stenting era.

BACKGROUND: Percutaneous coronary intervention (PCI) with stenting reduces adverse events in the general population compared with balloon angioplasty. The benefit of stents in high-risk patients normally excluded from clinical trials has not been well studied. Outcomes after PCIs in patients with chronic kidney disease (CKD) before and after widespread use of stents were compared. METHODS: All patients undergoing PCIs at our center within 2 periods selected for high and low stent use were included. Demographic, kidney and cardiac function, and PCI data were collected. Kaplan-Meier curves were constructed, and Cox proportional hazards analysis was used to assess the effect of high stent use on major adverse cardiac event, a composite of cardiac revascularization, myocardial infarction, or death 3 years after PCI. RESULTS: A total of 1,879 patients (780 patients, low stent use; 1,099 patients, high stent use; 18% and 94.1% stent use, respectively) with a mean age of 63 years, 73% men, and 26% of patients with a glomerular filtration rate less than 60 mL/min were included. At baseline, there was a greater prevalence of severe CKD, cardiac risk factors, and cardiovascular disease in the high-stent-use cohort. Major adverse cardiac events were reduced in the contemporary cohort (hazard ratio, 0.61; 95% confidence interval, 0.52 to 0.72); this benefit extended across all stages of kidney function. CONCLUSION: Patients with CKD undergoing PCI in the stenting era show improved outcomes. Additional studies are needed to determine optimal revascularization strategies in patients with CKD.

Aged↗
PubMed2005

Canadian randomized trial of hemoglobin maintenance to prevent or delay left ventricular mass growth in patients with CKD.

BACKGROUND: This randomized clinical trial is designed to assess whether the prevention and/or correction of anemia, by immediate versus delayed treatment with erythropoietin alfa in patients with chronic kidney disease, would delay left ventricular (LV) growth. Study design and sample size calculations were based on previously published Canadian data. METHODS: One hundred seventy-two patients were randomly assigned. The treatment group received therapy with erythropoietin alfa subcutaneously to maintain or achieve hemoglobin (Hgb) level targets of 12.0 to 14.0 g/dL (120 to 140 g/L). The control/delayed treatment group had Hgb levels of 9.0 +/- 0.5 g/dL (90 +/- 5 g/L) before therapy was started: target level was 9.0 to 10.5 g/dL (90 to 105 g/L). Optimal blood pressure and parathyroid hormone, calcium, and phosphate level targets were prescribed; all patients were iron replete. The primary end point is LV growth at 24 months. RESULTS: One hundred fifty-two patients were eligible for the intention-to-treat analysis: mean age was 57 years, 30% were women, 38% had diabetes, and median glomerular filtration rate was 29 mL/min (0.48 mL/s; range, 12 to 55 mL/min [0.20 to 0.92 mL/s]). Blood pressure and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use were similar in the control/delayed treatment and treatment groups at baseline. Erythropoietin therapy was administered to 77 of 78 patients in the treatment group, with a median final dose of 2,000 IU/wk. Sixteen patients in the control/delayed treatment group were administered erythropoietin at a median final dose of 3,000 IU/wk. There was no statistically significant difference between groups for the primary outcome of mean change in LV mass index (LVMI) from baseline to 24 months, which was 5.21 +/- 30.3 g/m2 in the control/delayed treatment group versus 0.37 +/- 25.0 g/m2 in the treatment group. Absolute mean difference between groups was 4.85 g/m2 (95% confidence interval, -4.0 to 13.7; P = 0.28). Mean Hgb level was greater in the treatment group throughout the study and at study end was 12.75 g/dL (127.5 g/L in treatment group versus 11.46 g/dL [114.6 g/L] in control/delayed treatment group; P = 0.0001). LV growth occurred in 20.1% in the treatment group versus 31% in the control/delayed treatment group (P = 0.136). In patients with a stable Hgb level, mean LVMI did not change (-0.25 +/- 26.7 g/m2), but it increased in those with decreasing Hgb levels (19.3 +/- 28.2 g/m2; P = 0.002). CONCLUSION: This trial describes disparity between observational and randomized controlled trial data: observed and randomly assigned Hgb level and LVMI are not linked; thus, there is strong evidence that the association between Hgb level and LVMI likely is not causal. Large randomized controlled trials with unselected patients, using morbidity and mortality as outcomes, are needed.

Adult↗
PubMed2005

Short and long alteplase dwells in dysfunctional hemodialysis catheters.

BACKGROUND: Hemodialysis catheter dysfunction (CD) is the inability to attain adequate blood pump speeds (BPS) and is attributed to thrombus or catheter malposition; alteplase (TPA) is often given in a variety of dwell times to treat CD. The purpose of this study was to determine if TPA dwell time affects short- or long-term catheter patency rates. METHODS: Sixty hemodialysis (HD) patients with CD, as defined by BPS of < 250 mL/min, were randomized to receive either 1- or > 48-hr (to subsequent HD run) TPA dwell. The primary outcomes were catheter patency (BPS of > 250 mL/min) at the subsequent HD run and catheter patency at 2 weeks. The secondary outcome was the time from study entry to the next catheter intervention (including subsequent TPA installation). RESULTS: After TPA installation, a 78% overall catheter patency rate was observed at the subsequent HD run, falling to 48% patency at 2 weeks. There is no statistically significant difference between the short and long TPA dwell groups for catheter patency at the subsequent HD run (76.9% vs. 79.4%) or at 2 weeks (42.3% vs. 52.9%). Multivariate analysis demonstrates that the use of TPA on two or more previous occasions is a predictor of TPA failure both at the subsequent HD run and at 2 weeks. TPA installation achieves a median catheter function time of only 14 days, after which CD reoccurs. CONCLUSION: This study demonstrates that although patency for the next HD run can be achieved with either short or long TPA dwell, neither is reliable in terms of long-term patency. Strategies that employ TPA for CD are temporary and allow a 2-week window during which more definitive therapies for HD access should be sought.

Aged↗
PubMed2005

Definition and classification of chronic kidney disease: a position statement from Kidney Disease: Improving Global Outcomes (KDIGO).

Chronic kidney disease (CKD) is a worldwide public health problem, with adverse outcomes of kidney failure, cardiovascular disease (CVD), and premature death. A simple definition and classification of kidney disease is necessary for international development and implementation of clinical practice guidelines. Kidney Disease: Improving Global Outcomes (KDIGO) conducted a survey and sponsored a controversies conference to (1) provide a clear understanding to both the nephrology and nonnephrology communities of the evidence base for the definition and classification recommended by Kidney Disease Quality Outcome Initiative (K/DOQI), (2) develop global consensus for the adoption of a simple definition and classification system, and (3) identify a collaborative research agenda and plan that would improve the evidence base and facilitate implementation of the definition and classification of CKD. The K/DOQI definition and classification were accepted, with clarifications. CKD is defined as kidney damage or glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) for 3 months or more, irrespective of cause. Kidney damage in many kidney diseases can be ascertained by the presence of albuminuria, defined as albumin-to-creatinine ratio >30 mg/g in two of three spot urine specimens. GFR can be estimated from calibrated serum creatinine and estimating equations, such as the Modification of Diet in Renal Disease (MDRD) Study equation or the Cockcroft-Gault formula. Kidney disease severity is classified into five stages according to the level of GFR. Kidney disease treatment by dialysis and transplantation should be noted. Simple, uniform classifications of CKD by cause and by risks for kidney disease progression and CVD should be developed.

Albuminuria↗
PubMed2005

Vitamin D and its analogues: do they protect against cardiovascular disease in patients with kidney disease?

BACKGROUND: Patients with chronic kidney disease (CKD) are at high risk for cardiovascular disease, and despite recent advances in hypertension control, anemia management, and dialysis adequacy, mortality remains high. Improved understanding of nontraditional risk factors, including those present at early phases in CKD, may lead to novel therapeutic strategies. CKD has been demonstrated to be an independent risk factor for cardiovascular disease in the general population, but data are lacking as to the associated potential abnormalities that occur in association with reduced glomerular filtration rate (GFR), which may contribute to this increased risk. Data are accumulating regarding the role of abnormalities of calcium, phosphorus, vitamin D, and parathyroid hormone (PTH) in cardiovascular disease. Vitamin D deficiency is present even in the early stages of CKD. Vitamin D plays a central role in calcium-phosphorus homeostasis, regulation of PTH, and formation and maintenance of bone. However, until recently, vitamin D has not been considered to have a biologic role in CKD beyond mineral regulation, or has been considered as a negative factor contributing to soft tissue and cardiovascular calcification. In light of recent observational studies showing an association of vitamin D therapy and survival benefit in hemodialysis patients, the effects of vitamin D on cardiovascular system have become a heavily debated issue. METHODS: A Medline search was performed to identify relevant literature describing the role of vitamin D in the pathogenesis of cardiovascular disease. Both the experimental and clinical literatures in English were reviewed. RESULTS: The accumulating published data demonstrate both associative relationships and mechanisms for biologic plausibility. The following three potential mechanisms may be important for the protective effects of vitamin D against cardiovascular disease mortality: vitamin D can inhibit various aspects of inflammation, which have been established as a key pathogenic mechanism in atherosclerosis; vitamin D exerts an antiproliferative effect on myocardial cell hypertrophy and proliferation, which underlies the pathogenesis of congestive heart failure; and vitamin D acts as a negative endocrine regulator for the renin-angiotensin system, which itself plays an important independent role in hypertension and cardiovascular health. CONCLUSION: Vitamin D deficiency might be an underestimated nonclassical risk factor for cardiovascular disease in CKD. Based on a review of the evidence, from both basic science and clinical studies, this article supports the possible protective role of vitamin D beyond its effect on mineral metabolism, and suggests the need for ongoing evaluation of the role of vitamin D in cardiovascular health in the CKD population.

Cardiovascular Diseases↗
PubMed2005

The need for optimal and coordinated management of CKD.

The prevalence of impaired kidney function has been estimated to be between 10% and 20% of adult populations in most countries worldwide. Reduced kidney function has been recognized as a risk factor for poor outcomes, and thus requires attention. Key aspects of management of CKD have been defined for referred populations, but not necessarily for those unreferred. In order to improve patient outcomes, there is a need to take a more holistic approach to the problem, by coordinating the efforts of policy makers, those involved in health care system redesign, clinicians, and researchers. In so doing, there should be an improvement in both identification and management of patients with impaired kidney function, whether cared for by primary care physicians, specialists, or nephrologists, and irrespective of the health care system.

Chronic Disease↗
PubMed2005

A new initiative in nephrology: 'Kidney disease: improving global outcomes'.

The burden of kidney disease: Improving global outcomes. Chronic kidney disease (CKD) is a worldwide public health problem with an increasing incidence and prevalence of patients requiring replacement therapy. There is an even higher prevalence of patients in earlier stages of CKD, with adverse outcomes such as kidney failure, cardiovascular disease, and premature death. Patients at earlier stages of CKD can be detected through laboratory testing and their treatment is effective in slowing the progression to kidney failure and reducing cardiovascular events. The evidence-based care of these patients are universal and independent of their geographic location. This paper describes the need to develop a uniform and global public health approach to the worldwide epidemic of CKD. It is to this end that a new initiative Kidney Disease: Improving Global Outcomes' has been established. Some current and future activities of this initiative are described. They include among others modification of the classification of CKD, the development of guidelines on hepatitis C, the organisation of consensus conferences like on Renal Osteodystrophy, and the creation of a website allowing the comparison of the five main English language clinical practice guidelines in kidney disease worldwide.

Chronic Disease↗
PubMed2005

N-acetylcysteine for prevention of radiographic contrast material-induced nephropathy: is the intravenous route best?

Use of oral N-acetylcysteine for preventing radiographic contrast material-induced nephropathy (RCIN) has become widespread, despite conflicting results from clinical trials and meta-analyses. The variability in study results may reflect differences in baseline risks in study patients, hydration regimens, choice of contrast agent, definition of RCIN, and the oral dosage formulation of N-acetylcysteine used. Injectable N-acetylcysteine recently has become available in the United States. Although oral N-acetylcysteine regimens are typically administered during a 48-hour period, more rapid intravenous administration could offer an important advantage for urgent procedures such as coronary angiography. However, the three published studies in which intravenous N-acetylcysteine protocols were used have produced divergent results, likely because of substantially different dosage regimens. With few intravenous studies available, clinicians may look to more broadly studied oral regimens to estimate equivalent intravenous dosages. In the oral studies, however, a wide range of formulations were used, and the bioavailability of each product was uncertain. In addition, the intravenous route circumvents first-pass metabolism, resulting in less glutathione production, perhaps compromising the antioxidant effects of N-acetylcysteine administration. Overall, little evidence exists that any studied N-acetylcysteine protocol improves clinical outcomes in terms of reducing length of hospital stay, need for dialysis, or mortality. Furthermore, N-acetylcysteine may directly affect serum creatinine level, which all clinical trials to date have used as a primary outcome measure. If oral or intravenous N-acetylcysteine is used with the intention of preventing RCIN, more established preventive measures should not be overlooked, including adequate hydration with isotonic saline, avoidance of potentially nephrotoxic drugs, and use of iso-osmolar radiographic contrast media.

Acetylcysteine↗
PubMed2004

The short- and long-term impact of multi-disciplinary clinics in addition to standard nephrology care on patient outcomes.

BACKGROUND: This two country case control study of incident dialysis patients evaluates the outcomes of patients exposed to formalized multi-disciplinary clinic (MDC) programmes vs standard nephrologist care. METHODS: Patients commencing dialysis in two centres (Vancouver, Canada and Cremona, Italy) were evaluated at and after dialysis start, as a function of MDC exposure vs nephrologist care alone. Only chronic kidney disease patients, with longer than 3 months of exposure to nephrology care, who had not previously received kidney replacement therapy were included. Study outcomes included laboratory parameters and survival. The MDC was similar in both countries and average exposure was 6-8 h per patient-year, as compared to 2-4 h for standard care. All patients had equal access to resources prior to dialysis and with respect to dialysis start, as all had been referred to the same local nephrology practices. RESULTS: During the evaluation period 288 patients commenced dialysis after receiving more than 3 months nephrology care prior to dialysis. There were no major demographic differences between the cohorts. Mean duration of nephrology care prior to dialysis was 42 months, and dialysis was initiated at similar low glomerular filtration rate (GFR), though statistically significantly different (7.0 and 8.4 ml/min/m2, P = 0.001). The MDC patients had higher haemoglobin (102 vs 90 g/l, P<0.0001), albumin (37.0 vs 34.8 g/l, P = 0.002) and calcium levels (2.29 vs 2.16 mmol/l, P<0.0001) at dialysis start. Survival was significantly better in the MDC group demonstrated by Kaplan-Meier analysis (P = 0.01). Cox proportional hazards analysis demonstrated standard nephrology clinic vs MDC attendance was a statistically significant independent predictor of death (hazards ratio = 2.17, 95% confidence interval 1.11-4.28) after adjusting for other variables known to impact outcomes. CONCLUSIONS: This analysis of outcomes in two different countries suggests that despite equal and long exposure to nephrology care prior to dialysis, there appears to be an association of survival advantage for those patients exposed to formalized clinic care in addition to standard nephrologist follow-up. While other known predictors of survival such as adequacy of dialysis and severity of illness measures were not included in the model, those parameters require time on dialysis to be accumulated. Thus, the data do suggest that knowledge of patient status at the time of dialysis start is important. Further research is needed to determine which specific components of care both prior to dialysis and after its commencement are most important with respect to outcomes.

Adult↗
PubMed2004

Clinical practice guidelines for chronic kidney disease in adults: Part II. Glomerular filtration rate, proteinuria, and other markers.

The Kidney Disease Outcome Quality Initiative of the National Kidney Foundation published clinical practice guidelines on chronic kidney disease in February 2002. Of the 15 guidelines, the first six are of greatest relevance to family physicians. Part II of this two-part review covers guidelines 4, 5, and 6. Glomerular filtration rate is the best overall indicator of kidney function. It is superior to the serum creatinine level, which varies with age, sex, and race and often does not reflect kidney function accurately. The glomerular filtration rate can be estimated using prediction equations that take into account the serum creatinine level and some or all of specific variables (age, sex, race, body size). In many patients, estimates of the glomerular filtration rate can replace 24-hour urine collections for creatinine clearance measurements. Urine dipsticks generally are acceptable for detecting proteinuria. To quantify proteinuria, the ratio of protein or albumin to creatinine in an untimed (spot) urine sample is an accurate alternative to measurement of protein excretion in a 24-hour urine collection. Patients with persistent proteinuria have chronic kidney disease. Other techniques for evaluating patients with chronic kidney disease include examination of urinary sediment, urine dipstick testing for red and white blood cells, and imaging studies of the kidneys (especially ultrasonography). These techniques also can help determine the underlying cause of chronic kidney disease. Family physicians should weigh the value of the National Kidney Foundation guidelines for their clinical practice based on the strength of evidence and perceived cost-effectiveness until additional evidence becomes available on the usefulness of the recommended quality indicators.

Adult↗
PubMed2004

The profile of cardiac patients with renal artery stenosis.

OBJECTIVES: We examined the prevalence and severity of renal artery stenosis (RAS) in patients undergoing cardiac catheterization who were deemed at risk for RAS based on clinical or laboratory criteria for study entry, but who had not previously been suspected of having RAS. BACKGROUND: The diagnosis of atherosclerotic RAS remains problematic because its clinical manifestations are nonspecific. METHODS: Consecutive patients undergoing non-emergent cardiac catheterization at a single institution during a 12-month period were evaluated using standardized clinical, laboratory, and angiographic criteria. Patients exhibiting at least one of four predefined selection criteria (severe hypertension, unexplained renal dysfunction, acute pulmonary edema with hypertension, or severe atherosclerosis) were prospectively registered and underwent coincident diagnostic renal angiography. RESULTS: Renal angiography was performed in 851 patients and was diagnostic in 837. Angiographically evident renal atherosclerosis was present in 39% of the population, with RAS > or =50% in 120 (14.3%) and severe stenosis (> or =70%) in 61 (7.3%). Severe stenosis was present in 48 (7%) patients with severe atherosclerosis, 38 (16%) with renal dysfunction, 25 (9%) with hypertension, and 2 (22%) with acute pulmonary edema with hypertension. The prevalence was higher in those exhibiting multiple selection criteria. In a multivariate model, severe RAS was associated with age, female gender, reduced creatinine clearance, increased systolic blood pressure, and peripheral or carotid artery disease. CONCLUSIONS: In a population at risk of, but not previously suspected of having RAS, severe RAS is associated with simple and readily determined clinical and laboratory patient characteristics. These data facilitate focused application of diagnostic renal angiography.

Adult↗
PubMed2004

A randomized controlled trial of intravenous N-acetylcysteine for the prevention of contrast-induced nephropathy after cardiac catheterization: lack of effect.

BACKGROUND: Contrast-induced nephropathy (CIN) after cardiac catheterization is common in patients with preexisting renal dysfunction. Studies of oral acetylcysteine to prevent CIN have produced conflicting results. Intravenous N-acetylcysteine (NAC) has logistic advantages in this setting. The objective of this study was to evaluate, in a blinded, randomized, placebo-controlled fashion, whether intravenous NAC reduced CIN in the setting of cardiac catheterization in patients with preexisting renal insufficiency. METHODS: Patients with renal dysfunction undergoing cardiac catheterization were randomly assigned to intravenous NAC 500 mg immediately before the procedure or placebo. All patients received isotonic saline (200 mL) beforehand, followed by 1.5 mL/kg per hour for 6 hours, unless contraindicated. Exclusion criteria included acute renal failure, creatinine >400 micromol/L, concurrent dialysis, unstable clinical status, and prior NAC use. Baseline creatinine was obtained immediately before the procedure and repeated 2 to 8 days later. The primary end point was the occurrence of CIN defined as a reduction in creatinine clearance from baseline of >5 mL/min (Cockcroft-Gault formula). RESULTS: The study was terminated early because of a determination of futility by the Data Safety Monitoring Committee after enrollment of 487 patients. The median baseline creatinine clearance was 44 mL/min (interquartile range, 33, 55). Median contrast received was 120 mL (interquartile range, 80, 175). Baseline characteristics were similar in the two groups. Altogether, 98 (22.0%) subjects had the primary end point: 23.3% in the NAC group and 20.7% in the placebo arm (P =.57). CONCLUSIONS: In this large, randomized trial, enrolling a high-risk group of patients with impaired renal function, intravenous NAC was ineffective in preventing CIN.

Acetylcysteine↗
PubMed2004

Translating research findings of chronic kidney disease management to clinical practice: Challenges and opportunities.

Chronic Kidney disease (CKD) has been identified as a public health epidemic, fueled in part by improved outcomes of both diabetic and cardiac patient populations, as well as by the increasing recognition that it is possible to identify CKD at earlier stages. The estimated 8 to 10 million Americans that have CKD, with its concomitant morbidity and mortality, have the potential to overwhelm the current system of specialty practice medicine and health care resources. How can clinicians, clinician scientists, and health care administrators translate research findings into clinical practice in an effective manner to improve the care of this burgeoning patient group? The challenge of translating research into clinical care requires identification of that which we do and do not know, communication of knowledge between those who do and do not know, and efficient collection of information for systematic evaluation. This article will describe the challenges of translating current research findings into clinical practice. There is a need to identify the complexity of CKD disease processes and issues associated with delivery of care and to describe the difficulties in the dissemination of new knowledge to physicians. Because of the propensity of CKD to affect identifiable groups of patients, we will discuss the potential challenges of these strategies given the racial, ethnic, and cultural diversity in North America. A potential solution to these challenges is a new paradigm of "process-based medicine" that integrates clinical and basic science research findings with multidisciplinary and shared care models of health care delivery. In this context, attention to advances in information technology, the cognitive processes that underlie physician learning, and the findings of outcome research may ensure true integration of clinical research and clinical practice.

Communication Barriers↗
PubMed2004

Effects of early and late intervention with epoetin alpha on left ventricular mass among patients with chronic kidney disease (stage 3 or 4): results of a randomized clinical trial.

It is not known whether prevention of anemia among patients with chronic kidney disease would affect the development or progression of left ventricular (LV) hypertrophy. A randomized controlled trial was performed with 155 patients with chronic kidney disease (creatinine clearance, 15 to 50 ml/min), with entry hemoglobin concentrations ([Hb]) of 110 to 120 g/L (female patients) or 110 to 130 g/L (male patients). Patients were monitored for 2 yr or until they required dialysis; the patients were randomized to receive epoetin alpha as necessary to maintain [Hb] between 120 and 130 g/L (group A) or between 90 and 100 g/L (group B). [Hb] increased for group A (from 112 +/- 9 to 121 +/- 14 g/L, mean +/- SD) and decreased for group B (from 112 +/- 8 to 108 +/- 13 g/L) (P < 0.001, group A versus group B). On an intent-to-treat analysis, the changes in LV mass index for the groups during the 2-yr period were not significantly different (2.5 +/- 20 g/m(2) for group A versus 4.5 +/- 20 g/m(2) for group B, P = NS). There was no significant difference between the groups in 2-yr mean unadjusted systolic BP (141 +/- 14 versus 138 +/- 13 mmHg) or diastolic BP (80 +/- 6 versus 79 +/- 7 mmHg). The decline in renal function in 2 yr, as assessed with nuclear estimations of GFR, also did not differ significantly between the groups (8 +/- 9 versus 6 +/- 8 ml/min per 1.73 m(2)). In conclusion, maintenance of [Hb] above 120 g/L, compared with 90 to 100 g/L, had similar effects on the LV mass index and did not clearly affect the development or progression of LV hypertrophy. The maintenance of [Hb] above 100 g/L for many patients in group B might have been attributable to the relative preservation of renal function.

Anemia↗
PubMed2004

Calcium, phosphate, and parathyroid hormone levels in combination and as a function of dialysis duration predict mortality: evidence for the complexity of the association between mineral metabolism and outcomes.

Current literature suggests associations between abnormal mineral metabolism (MM) to cardiovascular disease in dialysis populations, with conflicting results. MM physiology is complex; therefore, it was hypothesized that constellations of MM parameters, reflecting this complexity, would be predictive of mortality and that this effect would be modified by dialysis duration (DD). Prevalent dialysis patients in British Columbia, Canada, who had measurements of calcium (Ca), phosphate (Pi), and parathyroid hormone (iPTH) between January and March 2000 were followed prospectively until December 2002. Statistical analysis included Cox proportional hazard models with Ca, Pi, and iPTH alone and in combination as explanatory variables; analyses were stratified by DD. The 515 patients included in this analysis represent British Columbia and Canadian dialysis populations: 69% were on hemodialysis, mean age was 60 +/- 17 yr, 40% were female, and 34% had diabetes. Mean Ca and Pi values were 2.32 +/- 0.22 mmol/L and 1.68 +/- 0.59 mmol/L, respectively, and median iPTH was 15.8 pmol/L (25th to 75th percentile: 6.9 to 37.3 pmol/L). Serum Pi, after adjusting for demographic, dialysis type and adequacy, hemoglobin, and albumin, independently predicted mortality (risk ratio [RR], 1.56 per 1 mmol/L; 95% confidence interval [CI], 1.15 to 2.12; P = 0.004). When combinations of parameters were modeled (overall P = 0.003), the combinations of high serum Pi and Ca with high iPTH (RR, 3.71; 95% CI, 1.53 to 9.03; P = 0.004) and low iPTH (RR, 4.30; 95% CI, 2.01 to 9.22; P < 0.001) had highest risks for mortality as compared with the combination of high iPTH with normal serum Ca and Pi that had the lowest mortality and was used as index category. These effects varied across different strata of DD. This analysis demonstrates the importance of examining combinations of MM parameters as opposed to single variables alone and the effect of DD. In so doing, the complex interaction of time and MM can begin to be understand. Further exploration is required.

Calcium↗