Analysis of OPTN/UNOS registry suggests the number of HLA matches and not mismatches is a stronger independent predictor of kidney transplant survival

HLA matching and mismatching, while inversely related, are not exact opposites. Here we determined the independent effects of HLA matching and mismatching on outcomes in deceased donor kidney transplant recipients. The United Network for Organ Sharing database (1995-2012) was utilized and analyzed for delayed graft function, one-year acute rejection, and death-censored graft survival using combined multivariable models including HLA matching and mismatching. Sensitivity analyses were performed using the subgroup of deceased donor kidney transplant patients after 2003 with more uniform HLA nomenclature and resampling analyses using bootstrapping on complete data available from 96,236 recipients. Individually, both HLA matching and mismatching showed significant associations with graft survival. Adjusting the model to take into account both matching and mismatching simultaneously, the degree of HLA mismatching lost significance while matching continued to have a significant prediction for delayed graft function, the one-year acute rejection rate, and graft survival. Sensitivity analyses and bootstrapping showed similar results for all studied outcomes. Thus, analysis of this large cohort demonstrates the apparent greater association of HLA matching over HLA mismatching on both early allograft events as well as graft survival. Future analyses should preferentially utilize HLA matching as a covariate over mismatching for accurately reflecting impact on graft outcomes.

Unplanned 30-Day Readmissions after Parathyroidectomy in Patients with Chronic Kidney Disease: A Nationwide Analysis

Objective To examine rates of readmission after parathyroidectomy in patients with chronic kidney disease and determine primary etiologies, timing, and risk factors for these unplanned readmissions. Study Design Retrospective cohort study. Setting Nationwide Readmissions Database. Subjects and Methods The Nationwide Readmissions Database was queried for parathyroidectomy procedures performed in patients with chronic kidney disease between January 2013 and November 2013. Patient-, admission-, and hospital-level characteristics were compared for patients with and without at least 1 unplanned 30-day readmission. Outcomes of interest included rates, etiology, and timing of readmission. Multivariate logistic regression was used to identify predictors of 30-day readmission. Results There were 2756 parathyroidectomies performed in patients with chronic kidney disease with an unplanned readmission rate of 17.2%. Hypocalcemia/hungry bone syndrome accounted for 40% of readmissions. Readmissions occurred uniformly throughout the 30 days after discharge, but readmissions for hypocalcemia/hungry bone syndrome peaked in the first 10 days and decreased over time. Weight loss/malnutrition at time of parathyroidectomy and length of stay of 5 to 6 days conferred increased risk of readmission with adjusted odds ratios (aOR) of 3.31 (95% confidence interval [CI], 1.55-7.05; P = .002) and 1.87 (95% CI, 1.10-3.19; P = .02), respectively. Relative to primary hyperparathyroidism, parathyroidectomies performed for secondary hyperparathyroidism (aOR, 2.53; 95% CI, 1.07-5.95; P = .03) were associated with higher risk of readmission. Conclusion Postparathyroidectomy readmission rates for patients with chronic kidney disease are nearly 5 times that of the general population. Careful consideration of postoperative care and electrolyte management is crucial to minimize preventable readmissions in this vulnerable population.

Advanced glycation end products dietary restriction effects on bacterial gut microbiota in peritoneal dialysis patients; a randomized open label controlled trial

The modern Western diet is rich in advanced glycation end products (AGEs). We have previously shown an association between dietary AGEs and markers of inflammation and oxidative stress in a population of end stage renal disease (ESRD) patients undergoing peritoneal dialysis (PD). In the current pilot study we explored the effects of dietary AGEs on the gut bacterial microbiota composition in similar patients. AGEs play an important role in the development and progression of cardiovascular (CVD) disease. Plasma concentrations of different bacterial products have been shown to predict the risk of incident major adverse CVD events independently of traditional CVD risk factors, and experimental animal models indicates a possible role AGEs might have on the gut microbiota population. In this pilot randomized open label controlled trial, twenty PD patients habitually consuming a high AGE diet were recruited and randomized into either continuing the same diet (HAGE, n = 10) or a one-month dietary AGE restriction (LAGE, n = 10). Blood and stool samples were collected at baseline and after intervention. Variable regions V3-V4 of 16s rDNA were sequenced and taxa was identified on the phyla, genus, and species levels. Dietary AGE restriction resulted in a significant decrease in serum N^ε-(carboxymethyl) lysine (CML) and methylglyoxal-derivatives (MG). At baseline, our total cohort exhibited a lower relative abundance of Bacteroides and Alistipes genus and a higher abundance of Prevotella genus when compared to the published data of healthy population. Dietary AGE restriction altered the bacterial gut microbiota with a significant reduction in Prevotella copri and Bifidobacterium animalis relative abundance and increased Alistipes indistinctus, Clostridium citroniae, Clostridium hathewayi, and Ruminococcus gauvreauii relative abundance. We show in this pilot study significant microbiota differences in peritoneal dialysis patients’ population, as well as the effects of dietary AGEs on gut microbiota, which might play a role in the increased cardiovascular events in this population and warrants further studies.

Genetic identification of a common collagen disease in puerto ricans via identity-by-descent mapping in a health system

Achieving confidence in the causality of a disease locus is a complex task that often requires supporting data from both statistical genetics and clinical genomics. Here we describe a combined approach to identify and characterize a genetic disorder that leverages distantly related patients in a health system and population-scale mapping. We utilize genomic data to uncover components of distant pedigrees, in the absence of recorded pedigree information, in the multi-ethnic BioMe biobank in New York City. By linking to medical records, we discover a locus associated with both elevated genetic relatedness and extreme short stature. We link the gene, COL27A1, with a little-known genetic disease, previously thought to be rare and recessive. We demonstrate that disease manifests in both heterozygotes and homozygotes, indicating a common collagen disorder impacting up to 2% of individuals of Puerto Rican ancestry, leading to a better understanding of the continuum of complex and Mendelian disease.

Diseases often run in families. These disease are frequently linked to changes in DNA that are passed down through generations. Close family members may share these disease-causing mutations; so may distant relatives who inherited the same mutation from a common ancestor long ago. Geneticists use a method called linkage mapping to trace a disease found in multiple members of a family over generations to genetic changes in a shared ancestor. This allows scientists to pinpoint the exact place in the genome the disease-causing mutation occurred. Using computer algorithms, scientists can apply the same technique to identify mutations that distant relatives inherited from a common ancestor.

Belbin et al. used this computational technique to identify a mutation that may cause unusually short stature or bone and joint problems in up to 2% of people of Puerto Rican descent. In the experiments, the genomes of about 32,000 New Yorkers who have volunteered to participate in the BioMe Biobank and their health records were used to search for genetic changes linked to extremely short stature. The search revealed that people who inherited two copies of this mutation from their parents were likely to be extremely short or to have bone and joint problems. People who inherited one copy had an increased likelihood of joint or bone problems.

This mutation affects a gene responsible for making a form of protein called collagen that is important for bone growth. The analysis suggests the mutation first arose in a Native American ancestor living in Puerto Rico around the time that European colonization began. The mutation had previously been linked to a disorder called Steel syndrome that was thought to be rare. Belbin et al. showed this condition is actually fairly common in people whose ancestors recently came from Puerto Rico, but may often go undiagnosed by their physicians. The experiments emphasize the importance of including diverse populations in genetic studies, as studies of people of predominantly European descent would likely have missed the link between this disease and mutation.

Temporal trends of dialysis requiring acute kidney injury after orthotopic cardiac and liver transplant hospitalizations

Background

The epidemiology and outcomes of acute kidney injury (AKI) in prevalent non-renal solid organ transplant recipients is unknown.

Methods

We assessed the epidemiology of trends in acute kidney injury (AKI) in orthotopic cardiac and liver transplant recipients in the United States. We used the Nationwide Inpatient Sample to evaluate the yearly incidence trends (2002 to 2013) of the primary outcome, defined as AKI requiring dialysis (AKI-D) in hospitalizations after cardiac and liver transplantation. We also evaluated the trend and impact of AKI-D on hospital mortality and adverse discharge using adjusted odds ratios (aOR).

Results

The proportion of hospitalizations with AKI (9.7 to 32.7% in cardiac and 8.5 to 28.1% in liver transplant hospitalizations; p_trend<0.01) and AKI-D (1.63 to 2.33% in cardiac and 1.32 to 2.65% in liver transplant hospitalizations; p_trend<0.01) increased from 2002-2013. This increase in AKI-D was explained by changes in race and increase in age and comorbidity burden of transplant hospitalizations. AKI-D was associated with increased odds of in hospital mortality (aOR 2.85; 95% CI 2.11-3.80 in cardiac and aOR 2.00; 95% CI 1.55-2.59 in liver transplant hospitalizations) and adverse discharge [discharge other than home] (aOR 1.97; 95% CI 1.53-2.55 in cardiac and 1.91; 95% CI 1.57-2.30 in liver transplant hospitalizations).

Conclusions

This study highlights the growing burden of AKI-D in non-renal solid organ transplant recipients and its devastating impact, and emphasizes the need to develop strategies to reduce the risk of AKI to improve health outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0657-8) contains supplementary material, which is available to authorized users.

Apolipoprotein L1 Variants and Blood Pressure Traits in African Americans

BACKGROUND

African Americans (AA) are disproportionately affected by hypertension-related health disparities. Apolipoprotein L1 (APOL1) risk variants are associated with kidney disease in hypertensive AAs.

OBJECTIVES

This study assessed the APOL1 risk alleles' association with blood pressure traits in AAs.

METHODS

The discovery cohort included 5,204 AA participants from Mount Sinai's BioMe biobank. Replication cohorts included additional BioMe (n = 1,623), Vanderbilt BioVU (n = 1,809), and Northwestern NUgene (n = 567) AA biobank participants. Single nucleotide polymorphisms determining APOL1 G1 and G2 risk alleles were genotyped in BioMe and imputed in BioVU/NUgene participants. APOL1 risk alleles' association with blood pressure-related traits was tested in the discovery cohort, a meta-analysis of replication cohorts, and a combined meta-analysis under recessive and additive models after adjusting for age, sex, body mass index, and estimated glomerular filtration rate.

RESULTS

There were 14% to 16% of APOL1 variant allele homozygotes (2 copies of G1/G2) across cohorts. APOL1 risk alleles were associated under an additive model with systolic blood pressure (SBP) and age at diagnosis of hypertension, which was 2 to 5 years younger in the APOL1 variant allele homozygotes (Cox proportional hazards analysis, p value for combined meta-analysis [p_com] = 1.9 × 10^-5). APOL1 risk alleles were associated with overall SBP (p_com = 7.0 × 10^-8) and diastolic blood pressure (p_com = 2.8 × 10^-4). After adjustment for all covariates, those in the 20- to 29-year age range showed an increase in SBP of 0.94 ± 0.44 mm Hg (p_com = 0.01) per risk variant copy. APOL1-associated estimated glomerular filtration rate decline was observed starting a decade later in life in the 30- to 39-year age range.

CONCLUSIONS

APOL1 risk alleles are associated with higher SBP and earlier hypertension diagnoses in young AAs; this relationship appears to follow an additive model.

Urinalysis findings and urinary kidney injury biomarker concentrations

Introduction

Urinary biomarkers of kidney injury are presumed to reflect renal tubular damage. However, their concentrations may be influenced by other factors, such as hematuria or pyuria. We sought to examine what non-injury related urinalysis factors are associated with urinary biomarker levels.

Methods

We examined 714 adults who underwent cardiac surgery in the TRIBE-AKI cohort that did not experience post-operative clinical AKI (patients with serum creatinine change of ≥ 20% were excluded). We examined the association between urinalysis findings and the pre- and first post-operative urinary concentrations of 4 urinary biomarkers: neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), and liver fatty acid binding protein (L-FABP).

Results

The presence of leukocyte esterase and nitrites on urinalysis was associated with increased urinary NGAL (R² 0.16, p < 0.001 and R² 0.07, p < 0.001, respectively) in pre-operative samples. Hematuria was associated with increased levels of all 4 biomarkers, with a much stronger association seen in post-operative samples (R² between 0.02 and 0.21). Dipstick proteinuria concentrations correlated with levels of all 4 urinary biomarkers in pre-operative and post-operative samples (R² between 0.113 and 0.194 in pre-operative and between 0.122 and 0.322 in post-operative samples). Adjusting the AUC of post-operative AKI for dipstick proteinuria lowered the AUC for all 4 biomarkers at the pre-operative time point and for 2 of the 4 biomarkers at the post-operative time point.

Conclusions

Several factors available through urine dipstick testing are associated with increased urinary biomarker concentrations that are independent of clinical kidney injury. Future studies should explore the impact of these factors on the prognostic and diagnostic performance of these AKI biomarkers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0629-z) contains supplementary material, which is available to authorized users.

Plasma Biomarkers and Kidney Function Decline in Early and Established Diabetic Kidney Disease

Biomarkers of diverse pathophysiologic mechanisms may improve risk stratification for incident or progressive diabetic kidney disease (DKD) in persons with type 2 diabetes. To evaluate such biomarkers, we performed a nested case-control study (n=190 cases of incident DKD and 190 matched controls) and a prospective cohort study (n=1156) using banked baseline plasma samples from participants of randomized, controlled trials of early (ACCORD) and advanced (VA NEPHRON-D) DKD. We assessed the association and discrimination obtained with baseline levels of plasma TNF receptor-1 (TNFR-1), TNFR-2, and kidney injury molecule-1 (KIM-1) for the outcomes of incident DKD (ACCORD) and progressive DKD (VA-NEPHRON-D). At baseline, median concentrations of TNFR-1, TNFR-2, and KIM-1 were roughly two-fold higher in the advanced DKD population (NEPHRON-D) than in the early DKD population (ACCORD). In both cohorts, patients who reached the renal outcome had higher baseline levels than those who did not reach the outcome. Associations between doubling in TNFR-1, TNFR-2, and KIM-1 levels and risk of the renal outcomes were significant for both cohorts. Inclusion of these biomarkers in clinical models increased the area under the curve (SEM) for predicting the renal outcome from 0.68 (0.02) to 0.75 (0.02) in NEPHRON-D. Systematic review of the literature illustrated high consistency in the association between these biomarkers of inflammation and renal outcomes in DKD. In conclusion, TNFR-1, TNFR-2, and KIM-1 independently associated with higher risk of eGFR decline in persons with early or advanced DKD. Moreover, addition of these biomarkers to clinical prognostic models significantly improved discrimination for the renal outcome.

Representation and reporting of kidney disease in cerebrovascular disease: A systematic review of randomized controlled trials

Patients with kidney disease (KD) are at increased risk for cerebrovascular disease (CVD) and CVD patients with KD have worse outcomes. We aimed to determine the representation of KD patients in major randomized controlled trials (RCTs) of CVD interventions. We searched MEDLINE for reports of major CVD trials published through February 9, 2017. We excluded trials that did not report mortality outcomes, enrolled fewer than 100 participants, or were subgroup, follow-up, or post-hoc analyses. Two independent reviewers performed study selection and data extraction. We included 135 RCTs randomizing 194,977 participants. KD patients were excluded in 48 (35.6%) trials, but were less likely to be excluded from trials of class I/II recommended interventions (n = 7; 15.9%; p = 0.001) and more likely to be excluded in trials with registered protocols (45.5% vs. 22.4%; p = 0.007). Exclusion was lower in trials supported by academic or governmental grants compared to industry or combined funding (21.2% vs. 42.0% and 47.8%; p = 0.033 and 0.028, respectively). Among trials excluding KD patients, 24 (50.0%) used serum creatinine, 7 (14.6%) used estimated glomerular filtration rate or creatinine clearance, 7 (14.6%) used renal replacement therapy, and 19 (39.6%) used non-specific kidney-related criteria. Only 4 (3.0%) trials reported baseline renal function. No trials prespecified or reported subgroup analyses by baseline renal function. Although 19 (14.1%) trials reported the incidence of acute kidney injury, no trial examined adverse event rates according to renal function. In summary, more than one third of major CVD trials excluded patients with KD, primarily based on serum creatinine or non-specific criteria, and outcomes were not stratified by renal parameters. Therefore, purposeful efforts to increase inclusion of KD patients in CVD trials and evaluate the impact of renal function on efficacy and safety are needed to improve the quality of evidence for interventions in this vulnerable population.

The Effect of Depression in Chronic Hemodialysis Patients on Inpatient Hospitalization Outcomes

BACKGROUND/AIMS

Depression is common in patients with end-stage renal disease (ESRD) on hemodialysis (HD). Although, depression is associated with mortality, the effect of depression on in-hospital outcomes has not been studied as yet.

METHODS

We analyzed the National Inpatient Sample for trends and outcomes of hospitalizations with depression in patients with ESRD.

RESULTS

The proportion of ESRD hospitalizations with depression doubled from 2005 to 2013 (5.01-11.78%). Hospitalized patients on HD with depression were younger (60.47 vs. 62.70 years, p < 0.0001), female (56.93 vs. 47.81%, p < 0.0001), white (44.92 vs. 34.01%, p < 0.0001), and had higher proportion of comorbidities. However, there was a statistically significant lower risk of mortality in HD patients within the top 5 reasons for admissions.

CONCLUSION

There were significant differences in demographics and comorbidities for hospitalized HD patients with depression. Depression was associated with an increased rate of adverse effects in discharged patients, and decreased in-hospital mortality.

National Trends and Impact of Acute Kidney Injury Requiring Hemodialysis in Hospitalizations With Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is a common cause for hospitalization, but there are limited data regarding acute kidney injury requiring dialysis (AKI-D) in AF hospitalizations. We aimed to assess temporal trends and outcomes in AF hospitalizations complicated by AKI-D utilizing a nationally representative database.

METHODS AND RESULTS

Utilizing the Nationwide Inpatient Sample, AF hospitalizations and AKI-D were identified using diagnostic and procedure codes. Trends were analyzed overall and within subgroups and utilized multivariable logistic regression to generate adjusted odds ratios (aOR) for predictors and outcomes including mortality and adverse discharge. Between 2003 and 2012, 3751 (0.11%) of 3 497 677 AF hospitalizations were complicated by AKI-D. The trend increased from 0.3/1000 hospitalizations in 2003 to 1.5/1000 hospitalizations in 2012, with higher increases in males and black patients. Temporal changes in demographics and comorbidities explained a substantial proportion but not the entire trend. Significant comorbidities associated with AKI-D included mechanical ventilation (aOR 13.12; 95% CI 9.88-17.43); sepsis (aOR 8.20; 95% CI 6.00-11.20); and liver failure (aOR 3.72; 95% CI 2.92-4.75). AKI-D was associated with higher risk of in-hospital mortality (aOR 3.54; 95% CI 2.81-4.47) and adverse discharge (aOR 4.01; 95% CI 3.12-5.17). Although percentage mortality within AKI-D decreased over the decade, attributable risk percentage mortality remained stable.

CONCLUSIONS

AF hospitalizations complicated by AKI-D have quintupled over the last decade with differential increase by demographic groups. AKI-D is associated with significant morbidity and mortality. Without effective AKI-D therapies, focus should be on early risk stratification and prevention to avoid this devastating complication.

Geographical Variation in Peritoneal Dialysis Catheter Insertion and Initiation within the United States

Peritoneal dialysis (PD) is an effective but underutilized renal replacement therapy modality. There are limited data regarding geographical variation in PD catheter insertion and utilization of PD as a first renal replacement therapy in the United States. We explored the variation in catheter insertion and initiation of PD utilizing 2 large, nationally representative databases. The incidence of catheter insertion differed significantly by geographical region, being highest in the South (7.30/100 end-stage renal disease [ESRD] patients; 95% confidence [CI] interval 6.78 - 7.81) and lowest in the West (5.91/100 ESRD patients; 95% CI 5.43 - 6.38). Peritoneal dialysis initiation also differed by region, being highest in the West (7.10/100 ESRD patients; 95% CI 6.83 - 7.30) and lowest in the Northeast (5.12/100 ESRD patients; 95% CI 4.87 - 5.30). Interestingly, the Northeast region, with the lowest rate of PD utilization, had the highest number of nephrologists per population (3.95/100,000 persons), and the West, with the highest PD utilization, had the lowest number of nephrologists (2.54/100,000 persons). Reasons for this variation should be explored further and efforts should be made to standardize PD implementation throughout the United States.

Oral AGE restriction ameliorates insulin resistance in obese individuals with the metabolic syndrome: a randomised controlled trial

AIMS/HYPOTHESIS

We previously reported that obese individuals with the metabolic syndrome (at risk), compared with obese individuals without the metabolic syndrome (healthy obese), have elevated serum AGEs that strongly correlate with insulin resistance, oxidative stress and inflammation. We hypothesised that a diet low in AGEs (L-AGE) would improve components of the metabolic syndrome in obese individuals, confirming high AGEs as a new risk factor for the metabolic syndrome.

METHODS

A randomised 1 year trial was conducted in obese individuals with the metabolic syndrome in two parallel groups: L-AGE diet vs a regular diet, habitually high in AGEs (Reg-AGE). Participants were allocated to each group by randomisation using random permuted blocks. At baseline and at the end of the trial, we obtained anthropometric variables, blood and urine samples, and performed OGTTs and MRI measurements of visceral and subcutaneous abdominal tissue and carotid artery. Only investigators involved in laboratory determinations were blinded to dietary assignment. Effects on insulin resistance (HOMA-IR) were the primary outcome.

RESULTS

Sixty-one individuals were randomised to a Reg-AGE diet and 77 to an L-AGE diet; the data of 49 and 51, respectively, were analysed at the study end in 2014. The L-AGE diet markedly improved insulin resistance; modestly decreased body weight; lowered AGEs, oxidative stress and inflammation; and enhanced the protective factors sirtuin 1, AGE receptor 1 and glyoxalase I. The Reg-AGE diet raised AGEs and markers of insulin resistance, oxidative stress and inflammation. There were no effects on MRI-assessed measurements. No side effects from the intervention were identified. HOMA-IR came down from 3.1 ± 1.8 to 1.9 ± 1.3 (p < 0.001) in the L-AGE group, while it increased from 2.9 ± 1.2 to 3.6 ± 1.7 (p < 0.002) in the Reg-AGE group.

CONCLUSIONS/INTERPRETATION

L-AGE ameliorates insulin resistance in obese people with the metabolic syndrome, and may reduce the risk of type 2 diabetes, without necessitating a major reduction in adiposity. Elevated serum AGEs may be used to diagnose and treat 'at-risk' obesity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01363141 FUNDING: The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases (DK091231).

First Post-Operative Urinary Kidney Injury Biomarkers and Association with the Duration of AKI in the TRIBE-AKI Cohort

Background

We previously demonstrated that assessment of the duration of AKI, in addition to magnitude of rise in creatinine alone, adds prognostic information for long-term survival. We evaluated whether post-operative kidney injury biomarkers in urine collected immediately after cardiac surgery associate with duration of serum creatinine elevation.

Methods

We studied 1199 adults undergoing cardiac surgery in a prospective cohort study (TRIBE-AKI) and examined the association between the levels of five urinary biomarkers individually at 0–6 hours after surgery: interleukin-18 (IL-18), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), liver fatty acid binding protein (L-FABP) and albumin with duration of serum creatinine-based AKIN criteria for AKI (0 (no AKI), 1–2, 3–6, ≥7 days).

Results

Overall, 407 (34%) patients had at least stage 1 AKI, of whom 251 (61.7%) had duration of 1–2 days, 118 (28.9%) had duration 3–6 days, and 38 (9.3%) had duration of ≥7 days. Higher concentrations of all biomarkers (per log increase) were independently associated with a greater odds of a longer duration of AKI; odds ratios and 95% confidence intervals using ordinal logistic regression were the following: IL-18: 1.22, 1.13–1.32; KIM-1: 1.36, 1.21–1.52; albumin 1.20, 1.09–1.32; L-FABP 1.11, 1.04–1.19; NGAL 1.06, 1.00–1.14). AKI duration of 7 days or longer was associated with a 5-fold adjusted risk of mortality at 3 years.

Conclusions

There was an independent dose-response association between urinary levels of injury biomarkers immediately after cardiac surgery and longer duration of AKI. Duration of AKI was also associated with long term mortality. Future studies should explore the potential utility of these urinary kidney injury biomarkers to enrich enrollment of patients at risk for longer duration of AKI into trials of interventions to prevent or treat post-operative AKI.

Association of Urinary Biomarkers of Inflammation, Injury, and Fibrosis with Renal Function Decline: The ACCORD Trial

BACKGROUND AND OBJECTIVES

Current measures for predicting renal functional decline in patients with type 2 diabetes with preserved renal function are unsatisfactory, and multiple markers assessing various biologic axes may improve prediction. We examined the association of four biomarker-to-creatinine ratio levels (monocyte chemotactic protein-1, IL-18, kidney injury molecule-1, and YKL-40) with renal outcome.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used a nested case-control design in the Action to Control Cardiovascular Disease Trial by matching 190 participants with ≥40% sustained eGFR decline over the 5-year follow-up period to 190 participants with ≤10% eGFR decline in a 1:1 fashion on key characteristics (age within 5 years, sex, race, baseline albumin-to-creatinine ratio within 20 μg/mg, and baseline eGFR within 10 ml/min per 1.73 m(2)), with ≤10% decline. We used a Mesoscale Multiplex Platform and measured biomarkers in baseline and 24-month specimens, and we examined biomarker associations with outcome using conditional logistic regression.

RESULTS

Baseline and 24-month levels of monocyte chemotactic protein-1-to-creatinine ratio levels were higher for cases versus controls. The highest quartile of baseline monocyte chemotactic protein-1-to-creatinine ratio had fivefold greater odds, and each log increment had 2.27-fold higher odds for outcome (odds ratio, 5.27; 95% confidence interval, 2.19 to 12.71 and odds ratio, 2.27; 95% confidence interval, 1.44 to 3.58, respectively). IL-18-to-creatinine ratio, kidney injury molecule-1-to-creatinine ratio, and YKL-40-to-creatinine ratio were not consistently associated with outcome. C statistic for traditional predictors of eGFR decline was 0.70, which improved significantly to 0.74 with monocyte chemotactic protein-1-to-creatinine ratio.

CONCLUSIONS

Urinary monocyte chemotactic protein-1-to-creatinine ratio concentrations were strongly associated with sustained renal decline in patients with type 2 diabetes with preserved renal function.

Genomics in CKD: Is This the Path Forward?

Recent advances in genomics and sequencing technology have led to a better understanding of genetic risk in CKD. Genetics could account in part for racial differences in treatment response for medications including antihypertensives and immunosuppressive medications due to its correlation with ancestry. However, there is still a substantial lag between generation of this knowledge and its adoption in routine clinical care. This review summarizes the recent advances in genomics and CKD, discusses potential reasons for its underutilization, and highlights potential avenues for application of genomic information to improve clinical care and outcomes in this particularly vulnerable population.

Kidney-Failure Risk Projection for the Living Kidney-Donor Candidate

BACKGROUND

Evaluation of candidates to serve as living kidney donors relies on screening for individual risk factors for end-stage renal disease (ESRD). To support an empirical approach to donor selection, we developed a tool that simultaneously incorporates multiple health characteristics to estimate a person's probable long-term risk of ESRD if that person does not donate a kidney.

METHODS

We used risk associations from a meta-analysis of seven general population cohorts, calibrated to the population-level incidence of ESRD and mortality in the United States, to project the estimated long-term incidence of ESRD among persons who do not donate a kidney, according to 10 demographic and health characteristics. We then compared 15-year projections with the observed risk among 52,998 living kidney donors in the United States.

RESULTS

A total of 4,933,314 participants from seven cohorts were followed for a median of 4 to 16 years. For a 40-year-old person with health characteristics that were similar to those of age-matched kidney donors, the 15-year projections of the risk of ESRD in the absence of donation varied according to race and sex; the risk was 0.24% among black men, 0.15% among black women, 0.06% among white men, and 0.04% among white women. Risk projections were higher in the presence of a lower estimated glomerular filtration rate, higher albuminuria, hypertension, current or former smoking, diabetes, and obesity. In the model-based lifetime projections, the risk of ESRD was highest among persons in the youngest age group, particularly among young blacks. The 15-year observed risks after donation among kidney donors in the United States were 3.5 to 5.3 times as high as the projected risks in the absence of donation.

CONCLUSIONS

Multiple demographic and health characteristics may be used together to estimate the projected long-term risk of ESRD among living kidney-donor candidates and to inform acceptance criteria for kidney donors. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.).

National trends of acute kidney injury requiring dialysis in decompensated cirrhosis hospitalizations in the United States

BACKGROUND AND AIMS

Cirrhosis affects 5.5 million patients with estimated costs of US$4 billion. Previous studies about dialysis requiring acute kidney injury (AKI-D) in decompensated cirrhosis (DC) are from a single center/year. We aimed to describe national trends of incidence and impact of AKI-D in DC hospitalizations.

METHODS

We extracted our cohort from the Nationwide Inpatient Sample (NIS) from 2006-2012. We identified hospitalizations with DC and AKI-D by validated ICD9 codes. We analyzed temporal changes in DC hospitalizations complicated by AKI-D and utilized multivariable logistic regression models to estimate AKI-D impact on hospital mortality.

RESULTS

We identified a total of 3,655,700 adult DC hospitalizations from 2006 to 2012 of which 78,015 (2.1 %) had AKI-D. The proportion with AKI-D increased from 1.5 % in 2006 to 2.23 % in 2012; it was stable between 2009 and 2012 despite an increase in absolute numbers from 6773 to 13,930. The overall hospital mortality was significantly higher in hospitalizations with AKI-D versus those without (40.87 vs. 6.96 %; p < 0.001). In an adjusted multivariable analysis, adjusted odds ratio for mortality was 2.17 (95 % CI 2.06-2.28; p < 0.01) with AKI-D, which was stable from 2006 to 2012. Changes in demographics and increases in acute/chronic comorbidities and procedures explained temporal changes in AKI-D.

CONCLUSIONS

Proportion of DC hospitalizations with AKI-D increased from 2006 to 2009, and although this was stable from 2009 to 2012, there was an increase in absolute cases. These results elucidate the burden of AKI-D on DC hospitalizations and excess associated mortality, as well as highlight the importance of prevention, early diagnosis and testing of novel interventions in this vulnerable population.

Association between probiotic and yogurt consumption and kidney disease: insights from NHANES

Background

Data from experimental animals suggest that probiotic supplements may retard CKD progression. However, the relationship between probiotic use, frequent yogurt consumption (as a natural probiotic source), and kidney parameters have not been evaluated in humans.

Findings

We utilized NHANES data, and analyzed the association of probiotic alone (1999–2012) and yogurt/probiotic (2003–2006) use with albuminuria and eGFR after adjustment for demographic and clinical parameters. Frequent yogurt consumption was defined as thrice or more weekly over the year prior to the interview. Frequent yogurt/probiotic consumers had lower adjusted odds of developing combined outcome (albuminuria and/or eGFR < 60 ml/min/1.73 m²) compared to infrequent consumers (OR = 0.76; 95 % CI = 0.61-0.94). When evaluated separately, frequent consumers had lower odds of albuminuria and nonsignificant trend towards decreased odds of low eGFR compared to infrequent consumers. In the probiotic cohort, probiotic consumers were found to have a lower adjusted odds of albuminuria compared to nonusers (OR = 0.59; 95 % CI = 0.37–0.94).

Conclusion

Frequent yogurt and/or probiotics use is associated with decreased odds of proteinuric kidney disease. These hypothesis-generating results warrant further translational studies to further delineate the relationship between yogurt/probiotics with kidney dysfunction, as well as microbiome and dysbiosis as potential mediators.

Electronic supplementary material

The online version of this article (doi:10.1186/s12937-016-0127-3) contains supplementary material, which is available to authorized users.

Outcomes of dialysis catheters placed by the Y-TEC peritoneoscopic technique: a single-center surgical experience

BACKGROUND

In the last few years, peritoneal dialysis (PD) catheter placement techniques and outcomes have become important because of the growing population of PD patients. Although there are a growing number of catheters placed by the minimally invasive Y-TEC peritoneoscopic technique, there are still limited data on outcomes for these catheters, especially those placed by a surgeon. We aimed to conduct a retrospective study of our experience with PD catheters placed by the Y-TEC peritoneoscopic technique in our institution.

METHODS

We reviewed patients with peritoneoscopic PD catheter insertion over the last decade and described their complications and outcomes. In a secondary analysis, we compared the outcomes and complications of these catheters with those with open placement placed by the same surgeon.

RESULTS

We had complete data on 62 patients with peritoneoscopic catheter placement during the study period. The mean age was 55 years, 48.4% were females and the most common cause of end-stage renal disease was diabetes mellitus (33%). Surgical complications were seen in only 6/62 (9.6%) and peritonitis in 16/62 (26%) of peritoneoscopic catheters. Most catheters were used after 2 months of placement, while 12.3% were used within 2 months. When compared with 93 patients with open placement of catheters as a secondary analysis, peritoneoscopic catheters were found to have a higher 2-year survival.

CONCLUSION

Our large series of peritoneoscopically placed catheters by a surgeon demonstrate low surgical complications and peritonitis rates as well as superior 2-year survival compared with open placement of catheters.

Multinational Assessment of Accuracy of Equations for Predicting Risk of Kidney Failure: A Meta-analysis

IMPORTANCE

Identifying patients at risk of chronic kidney disease (CKD) progression may facilitate more optimal nephrology care. Kidney failure risk equations, including such factors as age, sex, estimated glomerular filtration rate, and calcium and phosphate concentrations, were previously developed and validated in 2 Canadian cohorts. Validation in other regions and in CKD populations not under the care of a nephrologist is needed.

OBJECTIVE

To evaluate the accuracy of the risk equations across different geographic regions and patient populations through individual participant data meta-analysis.

DATA SOURCES

Thirty-one cohorts, including 721,357 participants with CKD stages 3 to 5 in more than 30 countries spanning 4 continents, were studied. These cohorts collected data from 1982 through 2014.

STUDY SELECTION

Cohorts participating in the CKD Prognosis Consortium with data on end-stage renal disease.

DATA EXTRACTION AND SYNTHESIS

Data were obtained and statistical analyses were performed between July 2012 and June 2015. Using the risk factors from the original risk equations, cohort-specific hazard ratios were estimated and combined using random-effects meta-analysis to form new pooled kidney failure risk equations. Original and pooled kidney failure risk equation performance was compared, and the need for regional calibration factors was assessed.

MAIN OUTCOMES AND MEASURES

Kidney failure (treatment by dialysis or kidney transplant).

RESULTS

During a median follow-up of 4 years of 721,357 participants with CKD, 23,829 cases kidney failure were observed. The original risk equations achieved excellent discrimination (ability to differentiate those who developed kidney failure from those who did not) across all cohorts (overall C statistic, 0.90; 95% CI, 0.89-0.92 at 2 years; C statistic at 5 years, 0.88; 95% CI, 0.86-0.90); discrimination in subgroups by age, race, and diabetes status was similar. There was no improvement with the pooled equations. Calibration (the difference between observed and predicted risk) was adequate in North American cohorts, but the original risk equations overestimated risk in some non-North American cohorts. Addition of a calibration factor that lowered the baseline risk by 32.9% at 2 years and 16.5% at 5 years improved the calibration in 12 of 15 and 10 of 13 non-North American cohorts at 2 and 5 years, respectively (P = .04 and P = .02).

CONCLUSIONS AND RELEVANCE

Kidney failure risk equations developed in a Canadian population showed high discrimination and adequate calibration when validated in 31 multinational cohorts. However, in some regions the addition of a calibration factor may be necessary.

A National Perspective of Do-Not-Resuscitate Order Utilization Predictors in Intracerebral Hemorrhage

Nontraumatic intracerebral hemorrhage (ICH) is associated with substantial morbidity and mortality. Do-not-resuscitate (DNR) orders are linked to poorer outcomes in patients with ICH, possibly due to less active management. Demographic, regional, and social factors, not related to ICH severity, have not been adequately looked at as significant predictors of DNR utilization. We reviewed the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample (NIS) database in 2011 for adult ICH admissions and DNR status. We generated hierarchical 2-level multivariate regression models to estimate adjusted odds ratios. We analyzed 25 768 ICH hospitalizations, 18% of which (4620 hospitalizations) had DNR orders, corresponding to national estimates of 126 254 and 22 668, respectively. In multivariable regression, female gender, white or Hispanic/Latino ethnicity, no insurance coverage, and teaching hospitals were significantly associated with increased DNR utilization after adjusting for confounders. There was also significantly more interhospital variability in the lowest quartile of hospital volume. In conclusion, demographic factors and insurance status are significantly associated with increased DNR utilization, with more individual hospital variability in low-volume hospitals. The reasons for this are likely qualitative and linked to patient, provider, and hospital practices.

Incidence, Risk Factors, and Outcome Trends of Acute Kidney Injury in Elective Total Hip and Knee Arthroplasty

Over the past decade, there has been a marked increase in the number of primary and revision total hip and knee arthroplasties performed in the United States. Acute kidney injury (AKI) is a common complication of these procedures; however, little is known about its epidemiology in the elective arthroplasty population. We conducted a study to determine the incidence, risk factors, and outcomes of AKI after elective joint arthroplasty. Drawing on the Nationwide Inpatient Sample database, we found that the proportion of hospitalizations complicated by AKI increased rapidly from 0.5% in 2002 to 1.8% to 1.9% in 2012. Multivariate analysis revealed that the key risk factors for AKI were chronic kidney disease and the postoperative events of sepsis, acute myocardial infarction, and blood transfusion. Moreover, codiagnosis with chronic kidney disease increased the risk for AKI associated with all 3 postoperative events. After adjusting for confounders, we found an association between AKI and a significantly increased risk for in-hospital mortality and discharge to long-term facilities. AKI serves as an important quality indicator in elective hip and knee surgeries. With elective arthroplasties expected to rise, carefully planned approach to interdisciplinary perioperative care is essential to reduce both the risk and consequences of AKI.

Dialysis-requiring acute kidney injury among hospitalized adults with documented hepatitis C Virus infection: a nationwide inpatient sample analysis

Chronic hepatitis C virus (HCV) infection may cause kidney injury, particularly in the setting of cryoglobulinemia or cirrhosis; however, few studies have evaluated the epidemiology of acute kidney injury in patients with HCV. We aimed to describe national temporal trends of incidence and impact of severe acute kidney injury (AKI) requiring renal replacement 'dialysis-requiring AKI' in hospitalized adults with HCV. We extracted our study cohort from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project using data from 2004 to 2012. We defined HCV and dialysis-requiring acute kidney injury based on previously validated ICD-9-CM codes. We analysed temporal changes in the proportion of hospitalizations complicated by dialysis-requiring AKI and utilized survey multivariable logistic regression models to estimate its impact on in-hospital mortality. We identified a total of 4,603,718 adult hospitalizations with an associated diagnosis of HCV from 2004 to 2012, of which 51,434 (1.12%) were complicated by dialysis-requiring acute kidney injury. The proportion of hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly from 0.86% in 2004 to 1.28% in 2012. In-hospital mortality was significantly higher in hospitalizations complicated by dialysis-requiring acute kidney injury vs those without (27.38% vs 2.95%; adjusted odds ratio: 2.09; 95% confidence interval: 1.74-2.51). The proportion of HCV hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly between 2004 and 2012. Similar to observations in the general population, dialysis-requiring acute kidney injury was associated with a twofold increase in odds of in-hospital mortality in adults with HCV. These results highlight the burden of acute kidney injury in hospitalized adults with HCV infection.

Dialysis Requiring Acute Kidney Injury in Acute Cerebrovascular Accident Hospitalizations

BACKGROUND AND PURPOSE

The epidemiology of dialysis requiring acute kidney injury (AKI-D) in acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) admissions is poorly understood with previous studies being from a single center or year.

METHODS

We used the Nationwide Inpatient Sample to evaluate the yearly incidence trends of AKI-D in hospitalizations with AIS and ICH from 2002 to 2011. We also evaluated the trend of impact of AKI-D on in-hospital mortality and adverse discharge using adjusted odds ratios (aOR) after adjusting for demographics and comorbidity indices.

RESULTS

We extracted a total of 3,937,928 and 696,754 hospitalizations with AIS and ICH, respectively. AKI-D occurred in 1.5 and 3.5 per 1000 in AIS and ICH admissions, respectively. Incidence of admissions complicated by AKI-D doubled from 0.9/1000 to 1.7/1000 in AIS and from 2.1/1000 to 4.3/1000 in ICH admissions. In AIS admissions, AKI-D was associated with 30% higher odds of mortality (aOR, 1.30; 95% confidence interval, 1.12-1.48; P<0.001) and 18% higher odds of adverse discharge (aOR, 1.18; 95% confidence interval, 1.02-1.37; P<0.001). Similarly, in ICH admissions, AKI-D was associated with twice the odds of mortality (aOR, 1.95; 95% confidence interval, 1.61-2.36; P<0.01) and 74% higher odds of adverse discharge (aOR, 1.74; 95% confidence interval, 1.34-2.24; P<0.01). Attributable risk percent of mortality was high with AKI-D (98%-99%) and did not change significantly over the study period.

CONCLUSIONS

Incidence of AKI-D complicating hospitalizations with cerebrovascular accident continues to grow and is associated with increased mortality and adverse discharge. This highlights the need for early diagnosis, better risk stratification, and preparedness for need for complex long-term care in this vulnerable population.

Systematic oral hydration with water is similar to parenteral hydration for prevention of contrast-induced nephropathy: an updated meta-analysis of randomised clinical data

Background

Contrast-induced nephropathy (CIN) is the third most common cause of hospital-acquired kidney injury and is related to increased long-term morbidity and mortality. Adequate intravenous (IV) hydration has been demonstrated to lessen its occurrence. Oral (PO) hydration with water is inexpensive and readily available but its role for CIN prevention is yet to be determined.

Methods

PubMed, EMBASE and the Cochrane Central register of controlled trials (CENTRAL) databases were searched until April 2015 and studies were selected using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. All randomised clinical trials with head-to-head comparison between PO and IV hydration were included.

Results

A total of 5 studies with 477 patients were included in the analysis, 255 of those receiving PO water. The incidence of CIN was statistically similar in the IV and PO arms (7.7% and 8.2%, respectively; relative risk 0.97; 95% CI 0.36 to 2.94; p=0.95). The incidence of CIN was statistically similar in the IV and PO arms in patients with chronic kidney disease and with normal renal function. Rise in creatinine at 48–72 h was lower in the PO hydration group compared with IV hydration (pooled standard mean difference 0.04; 95% CI 0.03 to 0.06; p<0.001; I²=62%).

Conclusions

Our meta-analysis shows that systematic PO hydration with water is at least as effective as IV hydration with saline to prevent CIN. PO hydration is cheaper and more easily administered than IV hydration, thus making it more attractive and just as effective.

A Nationwide Analysis of Outcomes of Weekend Admissions for Intracerebral Hemorrhage Shows Disparities Based on Hospital Teaching Status

BACKGROUND AND PURPOSE

With the "weekend effect" being well described, the Brain Attack Coalition released a set of "best practice" guidelines in 2005, with the goal to uniformly provide standard of care to patients with stroke. We attempted to define a "weekend effect" in outcomes among patients with intracranial hemorrhage (ICH) over the last decade, utilizing the Nationwide Inpatient Sample (NIS) data. We also attempted to analyze the trend of such an effect.

MATERIALS AND METHODS

We determined the association of ICH weekend admissions with hospital outcomes including mortality, adverse discharge, length of stay, and cost compared to weekday admissions using multivariable logistic regression. We extracted our study cohort from the NIS, the largest all-payer data set in the United States.

RESULTS

Of 485 329 ICH admissions from 2002 to 2011, 27.5% were weekend admissions. Overall, weekend admissions were associated with 11% higher odds of in-hospital mortality. When analyzed in 3-year groups, excess mortality of weekend admissions showed temporal decline. There was higher mortality with weekend admissions in nonteaching hospitals persisted (odds ratios 1.16, 1.13, and 1.09, respectively, for 3-year subgroups). Patients admitted during weekends were also 9% more likely to have an adverse discharge (odds ratio 1.09; 95% confidence interval: 1.07-1.11; P < .001) with no variation by hospital status. There was no effect of a weekend admission on either length of stay or cost of care.

CONCLUSION

Nontraumatic ICH admissions on weekends have higher in-hospital mortality and adverse discharge. This demonstrates need for in-depth review for elucidating this discrepancy and stricter adherence to standard-of-care guidelines to ensure uniform care.

Update on glycemic control for the treatment of diabetic kidney disease

Diabetic kidney disease (DKD) is a common, complex condition that has become a significant public health problem. The beneficial effects of intensive glycemic control in type 1 diabetes mellitus on development of DKD are proven; however, the evidence for nephroprotection in patients with type 2 diabetes is conflicting. Moreover, a strategy of intensive glycemic control increases the risk for adverse effects (hypoglycemic episodes) with no obvious impact on macrovascular events or mortality in recent large randomized controlled trials. The risk for hypoglycemia with intensive therapy is heightened in patients with significant renal dysfunction, due to decreased renal clearance of insulin. Establishing an ideal level of glycemic control in patients requires an individualized approach taking into account duration of diabetes and presence of coexisting comorbidities and pre-existing DKD. In this article, we review the available evidence from both observational studies and randomized controlled trials and provide suggestions about evaluating the potential benefits and harm from intensive glycemic control in patients. We also discuss how in the future, a personalized approach using biomarkers might help identify patients most likely to respond as well as those most susceptible to harm. We believe that using the optimal level of glycemic control in diabetic patients using a multi-pronged strategy will improve individual patient outcomes and decrease the overall burden of morbidity and mortality.

Incidence of cardiovascular events and gastrointestinal bleeding in patients receiving clopidogrel with and without proton pump inhibitors: an updated meta-analysis

Background

Dual antiplatelet therapy is the standard of care after coronary stent placement but increases the bleeding risk. The effects of proton pump inhibitors (PPIs) on clopidogrel metabolism have been described, but the clinical significance is not yet definitive. We aimed to do an updated meta-analysis comparing outcomes in patients receiving clopidogrel with and without PPIs.

Methods

We systematically searched PubMed, Scopus and the Cochrane Central Register of Controlled Trials for randomised controlled trials (RCTs) and controlled observational studies in patients taking clopidogrel stratified by concomitant PPI use. Heterogeneity was examined with the Cochran Q test and I² statistics; p values inferior to 0.10 and I² >25% were considered significant for heterogeneity.

Results

We included 39 studies with a total of 214 851 patients, of whom 73 731 (34.3%) received the combination of clopidogrel and a PPI. In pooled analysis, all-cause mortality, myocardial infarction, stent thrombosis and cerebrovascular accidents were more common in patients receiving both drugs. However, among 23 552 patients from eight RCTs and propensity-matched studies, there were no significant differences in mortality or ischaemic events between groups. The use of PPIs in patients taking clopidogrel was associated with a significant reduction in the risk of gastrointestinal bleeding.

Conclusions

The results of our meta-analysis suggest that PPIs are a marker of increased cardiovascular risk in patients taking clopidogrel, rather than a direct cause of worse outcomes. The pharmacodynamic interaction between PPIs and clopidogrel most likely has no clinical significance. Furthermore, PPIs have the potential to decrease gastrointestinal bleeding in clopidogrel users.

Trimetazidine Decreases Risk of Contrast-Induced Nephropathy in Patients With Chronic Kidney Disease

Objectives:

We sought to synthesize and analyze the available data from randomized controlled trials (RCTs) for trimetazidine (TMZ) in the prevention of contrast-induced nephropathy (CIN).

Background:

Contrast-induced nephropathy after coronary angiography is associated with poor outcomes. Trimetazidine is an anti-ischemic drug that might reduce incidence of CIN, but current data are inconclusive.

Methods:

We searched MEDLINE/PubMed, EMBASE, Scopus, Cochrane Library, Web of Science, and ScienceDirect electronic databases for RCTs comparing intravenous hydration with normal saline (NS) and/or N-acetyl cysteine (NAC) versus TMZ plus NS ± NAC for prevention of CIN. We used RevMan 5.2 for statistical analysis with the fixed effects model.

Results:

Of the 808 studies, 3 RCTs met criteria with 290 patients in the TMZ plus NS ± NAC group and 292 patients in the NS ± NAC group. The mean age of patients was 59.5 years, and baseline serum creatinine ranged from 1.3 to 2 mg/dL. Trimetazidine significantly reduced the incidence of CIN by 11% (risk difference 0.11; 95% confidence interval, 0.16-0.06; P < .01). There was no significant heterogeneity between the studies (I2 statistic = 0). The number needed to treat to prevent 1 episode of CIN was 9.

Conclusions:

The addition of TMZ to NS ± NAC significantly decreased the incidence of CIN in patients undergoing coronary angiography. In conclusion, TMZ could be considered as a potential tool for prevention of CIN in patients with renal dysfunction.

Abstract W P421: Trend in Concurrent Hospitalization for Moyamoya and Sickle Cell Disease: An Analysis of Nationwide Inpatient Sample Data

BACKGROUND: The association between Moyamoya disease and sickle cell disease is well recognized in the literature. However, there is limited data on inpatient admission of concurrent sickle cell disease and Moyamoya disease. We sought to determine the trend in incidence of admissions of concurrent Moyamoya and sickle cell disease as well as the most common presentation of these admissions.

METHODS: We reviewed the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample (NIS) database from 2000-2011 for concurrent Moyamoya and sickle cell admissions using the ICD 9-CM codes We obtained data on gender, clinical presentation, procedures, co-morbidities and patient outcomes

RESULTS: From 2000 to 2011, an estimated patients 756 (weighted (n)=3692) with co-existing Moyamoya disease and sickle cell disease were admitted. The incidence of admission for concurrent disease increased significantly from 0.04/100,000 admissions in 2000 to 0.21/100,000 admissions in 2011(figure 1). This was very significant using the Cochrane Armitage trend test(p<0.001). The most likely reasons for admissions were ischemic stroke(7.2)% followed by hemorrhagic stroke(2.8 and transient ischemic attack(1.2%) (p = 0.0116). The most commonly performed treatment procedures included packed cell transfusion(33.7%) followed by exchange transfusion (8.8%). However there was no significant change in mortality from 2000-2011.

CONCLUSION: The number of hospitalizations due to concurrent Moyamoya and sickle cell disease has increased significantly over the last decade and are likely to present with a cerebrovascular accident. Thus, it is important to maintain a high degree of suspicion for Moyamoya disease in sickle cell disease patients presenting with neurological symptoms since this could potentially impact their management.

Development and validation of an electronic phenotyping algorithm for chronic kidney disease

Twenty-six million Americans are estimated to have chronic kidney disease (CKD) with increased risk for cardiovascular disease and end stage renal disease. CKD is frequently undiagnosed and patients are unaware, hampering intervention. A tool for accurate and timely identification of CKD from electronic medical records (EMR) could improve healthcare quality and identify patients for research. As members of eMERGE (electronic medical records and genomics) Network, we developed an automated phenotyping algorithm that can be deployed to identify rapidly diabetic and/or hypertensive CKD cases and controls in health systems with EMRs It uses diagnostic codes, laboratory results, medication and blood pressure records, and textual information culled from notes. Validation statistics demonstrated positive predictive values of 96% and negative predictive values of 93.3. Similar results were obtained on implementation by two independent eMERGE member institutions. The algorithm dramatically outperformed identification by ICD-9-CM codes with 63% positive and 54% negative predictive values, respectively.

Cilostazol increases patency and reduces adverse outcomes in percutaneous femoropopliteal revascularisation: a meta-analysis of randomised controlled trials

Background

Cilostazol is an oral antiplatelet agent currently indicated for treatment of intermittent claudication. There is evidence that cilostazol may reduce femoropopliteal restenosis after percutaneous endovascular intervention.

Methods

We searched PubMed, Scopus and Cochrane databases from 1966 through September 2013 for randomised controlled trials (RCTs) evaluating the addition of cilostazol to standard care in patients receiving femoropopliteal endovascular treatment. Restenosis, target lesion revascularisation and combined adverse outcomes (death, revascularisation and amputation) within 1–2 years postprocedure were evaluated.

Results

Of 205 articles, three RCTs were included in the analysis. The pooled data provided a total of 396 patients, 195 of whom received cilostazol. When compared to standard medical therapy alone, cilostazol significantly reduced the risk of restenosis (risk difference −0.20; 95% CI −0.29 to −0.11; p<0.0001; number needed to treat 5), target lesion revascularisation (risk difference −0.17; 95% CI −0.25 to −0.09; p<0.0001; number needed to treat 6). Death and amputation were not different in between groups.

Conclusions and limitation

Cilostazol significantly increases femoropopliteal patency and decreases adverse outcomes in percutaneous endovascular intervention. However, further RCTs are needed because of limited sample size; this meta-analysis represents the best current evidence.

Effect of Genetic African Ancestry on eGFR and Kidney Disease

Self-reported ancestry, genetically determined ancestry, and APOL1 polymorphisms are associated with variation in kidney function and related disease risk, but the relative importance of these factors remains unclear. We estimated the global proportion of African ancestry for 9048 individuals at Mount Sinai Medical Center in Manhattan (3189 African Americans, 1721 European Americans, and 4138 Hispanic/Latino Americans by self-report) using genome-wide genotype data. CKD-EPI eGFR and genotypes of three APOL1 coding variants were available. In admixed African Americans and Hispanic/Latino Americans, serum creatinine values increased as African ancestry increased (per 10% increase in African ancestry, creatinine values increased 1% in African Americans and 0.9% in Hispanic/Latino Americans; P≤1x10(-7)). eGFR was likewise significantly associated with African genetic ancestry in both populations. In contrast, APOL1 risk haplotypes were significantly associated with CKD, eGFR<45 ml/min per 1.73 m(2), and ESRD, with effects increasing with worsening disease states and the contribution of genetic African ancestry decreasing in parallel. Using genetic ancestry in the eGFR equation to reclassify patients as black on the basis of ≥50% African ancestry resulted in higher eGFR for 14.7% of Hispanic/Latino Americans and lower eGFR for 4.1% of African Americans, affecting CKD staging in 4.3% and 1% of participants, respectively. Reclassified individuals had electrolyte values consistent with their newly assigned CKD stage. In summary, proportion of African ancestry was significantly associated with normal-range creatinine and eGFR, whereas APOL1 risk haplotypes drove the associations with CKD. Recalculation of eGFR on the basis of genetic ancestry affected CKD staging and warrants additional investigation.

Patient satisfaction and resident postgraduate year status

Purpose

– Patient satisfaction has been recognized as an important variable affecting healthcare behavior. However, there are limited data on the relationship between doctor post-graduate year (PGY) status and patient satisfaction with provider interpersonal skills and humanistic qualities. The authors aims to assess this relationship using an American Board of Internal Medicine (ABIM) questionnaire.

Design/methodology/approach

– Participants were: patients attending a primary care clinic at a large urban academic hospital; and physicians treating them. The survey questionnaire was the ABIM patient satisfaction instrument; ten questions pertaining to humanistic qualities and communication skills with responses from poor to excellent. Mann Whitney U test and multi-variable logistic regression analyses were used to explore score differences by PGY level.

Findings

– The postgraduate year one (PGY1) had higher patient-satisfaction levels compared to PGY2/PGY3 residents. The PGY1 level residents were more likely to score in the 90th percentile and this remained constant even after adjusting for confounders.

Research limitations/implications

– The research was a single-center study and may have been subject to confounding factors such as patient personality types and a survey ceiling effect. The survey's cross-sectional nature may also be a potential limitation.

Practical implications

– Patient satisfaction varies significantly with PGY status. Though clinical skills may improve with increasing experience, findings imply that interpersonal and humanistic qualities may deteriorate.

Originality/value

– The study is the first to assess patient satisfaction with PGY status and provides evidence that advanced trainees may need support to keep their communication skills and humanistic qualities from deteriorating as stressors increase to ensure optimal patient satisfaction.

Internal medicine residents' perspectives on effects of 2011 ACGME work hour regulations on patient care

BACKGROUND

The Accreditation Council for Graduate Medical Education (ACGME) introduced new work hour limitations in July 2011.

PURPOSES

The aim is to assess internal medicine residents' perspectives on the impact of these limitations on their ability to discharge patient care duties.

METHODS

An anonymous survey was administered to 158 medicine residents in an urban university-affiliated internal medicine residency program. Residents' perspectives on various aspects of patient care were recorded on a 5-point Likert-type scale.

RESULTS

The response rate was 62%. The majority of residents (80%) agreed that patients had adequate continuity of care. Most residents agreed that they had enough time to follow up on consult notes (64% agreed) and investigations (80% agreed) daily. Most PGY-1 residents (59%) reported having enough time to prepare sign-outs. Most (60%) residents felt that reducing handoffs would improve patient care.

CONCLUSIONS

Most residents believe that the new work hour limitations would continue to uphold patient safety, but handoffs in care must be restricted.

Phosphorus and the kidney: What is known and what is needed

A major role of the kidneys is to maintain phosphorus homeostasis. High serum phosphorus has been linked to all-cause and cardiovascular mortality in chronic kidney disease (CKD) both before and after initiation of renal replacement therapy. Considering the clinical implications of uncontrolled hyperphosphatemia, maintenance of phosphorus concentrations within an optimum range is standard of care in this patient population. Recently, the epidemiologic associations between serum phosphorus and worse outcome have been extended to the general population. This becomes even more important in view of the increasing dietary phosphorus intake in the American diet due in large part to the greater consumption of foods processed with phosphate additives. A greater understanding of mechanisms and epidemiology of altered phosphorus metabolism and disease in CKD may help clarify the possible role of excess dietary phosphorus as a health risk factor in the general population.

Efficacy and safety of dual calcium channel blockade for the treatment of hypertension: a meta-analysis

BACKGROUND

Dual calcium-channel blocker (CCB) with a dihydropyridine (DHP) and a nondihydropyridine (NDHP) has been proposed for hypertension treatment. However, the safety and efficacy of this approach is not well known.

METHODS

A MEDLINE/EMBASE/CENTRAL search for randomized clinical trials published on this topic from 1966 to February 2012 was performed. Efficacy outcomes of decrease in systolic (SBP) and diastolic (DBP) blood pressures from baseline, changes in heart rate (HR), and adverse effects were compared between dual CCB therapy vs. DHP or NDHP. SBP, DBP, and HR were expressed as weighted mean deviation (WMD).

RESULTS

A total of 6 studies with 153 patients were included. Dual CCB produced a significantly greater reduction in SBP (21.6±9.2 mmHg) from baseline than DHP (10.3±6.3 mmHg (WMD = 10.9 mmHg, P < 0.0001)) or NDHP (8.9±4.2 mmHg (WMD = 14.1 mmHg, P = 0.002)). Dual CCB therapy reduced DBP from baseline more than either monotherapy (dual CCB = 17.5±10.2 mmHg vs. DHP = 11.6±8.7 mmHg, WMD = 5.5 mmHg, P < 0.001; and NDHP = 10.5±5.6 mmHg, WMD = 5.3 mmHg, P = 0.03). Dual CCB therapy had significantly lower HR compared to DHP (P < 0.001) but was comparable to NDHP (P = 0.12) (Delta change dual CCB = -4.0±3.5 vs. DHP = -2.0±1.5 and NDHP = -6.0±5.0 beats/min). Dual CCB therapy did not increase adverse effects.

CONCLUSIONS

Dual CCB therapy lowers blood pressure significantly better than CCB monotherapy, without an increase in adverse events. However, given the lack of long-term outcome data on efficacy and safety, dual CCB therapy should be used with restraint, if at all. Large-scale long-term trials are needed to further evaluate such a strategy.

Severe bradycardia caused by a single dose of lithium

Lithium is used as a mood stabilizer in patients with manic-depressive disorder. It is a drug that requires close monitoring due to its narrow therapeutic window and many side effects. There are several case reports of lithium side effects and toxicity occurring even at the therapeutic levels. Cardiac toxicity is observed in approximately 5% of patients; however, severe bradycardia caused by a single dose of lithium is exceedingly rare. We herein report a case of severe symptomatic bradycardia in a young man that occurred after a single dose of lithium. This case emphasizes the need to closely monitor patients when initiating therapy, even before the lithium levels are high enough to be detected.

The Austrian syndrome: a case report and review of the literature

A 61-year-old man presented with fever and altered mental status. He was intubated for respiratory distress and was found to have multilobar pneumonia for which antibiotic therapy was instituted. However, his mental status continued to deteriorate despite appropriate antibiotic therapy for his pneumonia. The results from lumar puncture revealed meningitis and endocarditis was evident on a trans-esophageal echocardiogram. His blood and respiratory cultures grew Streptococcus pneumoniae. The patient was diagnosed with Austrian syndrome. After appropriate changes to his antibiotic regimen and an aortic valve replacement, he recovered and was discharged.

Association of hypertension and bone mineral density in an elderly African American female population

BACKGROUND

Recent studies have shown that hypertension is inversely correlated with bone mineral density (BMD) as determined by dual energy x-ray absorptiometery (DXA) in different ethnic groups. But in most published studies, either the sample size was small or the study was limited by different measurement methods. These limitations leave this association controversial and inconclusive. The current study utilizes a sample of African American females referred for clinical screening of osteoporosis in our center to find out if any association of high blood pressure and BMD in this ethnic group exists. The secondary endpoint was to determine the effect of thiazide diuretics on BMD of the elderly African American females because, theoretically, thiazides are considered to have a positive impact on BMD.

METHODS

In this retrospective, cross-sectional study, 10 years of data were reviewed from 1113 medical records of African American females aged 65 years and older whose BMD values were measured by DXA at the lumbar spine (L1-L4) and both femoral necks (the standard sites for BMD determination) along with their T scores and Z scores (used to determine osteopenia vs osteoporosis). Our exclusion criteria included patients who: (1) were current smokers, (2) had a previous oophorectomy, (3) had a history of corticosteroid use, (4) had a history of biphosphonate use, (5) were on hormone replacement therapy, and (6) were diabetic and taking either pioglitazones or roziglitazones. A total of 148 patients were excluded from the analysis due to either incomplete data or exclusion criteria. The remaining sample was then divided into 2 groups based on their hypertensive status. For the subanalysis, the hypertensive group was further divided into 2 additional groups based on their thiazide usage.

RESULTS

We had complete data on 965 participants, of which 631 (65.3%) had a history of hypertension and 334 (34.7%) did not. Out of 631 hypertensive patients, 173 were found to be using thiazide diuretics as antihypertensive medication, while 458 were without thiazide diurectic use. The proportion of patients with both osteopenia and osteoporosis was similar in those with and without hypertension (50% vs 50%, p = .95 for osteopenia; 18% vs 19%, p = .95 for osteoporosis). There was no significant difference between the BMD at the lumbar spine, and right and left femoral necks between patients with and without hypertension. This lack of association held true when comparing the mean T scores and Z scores at the above sites. Within patients with a history of hypertension, there were no significant differences in the BMD, T score or Z score at any site with and without a history of thiazide diuretic use.

CONCLUSION

Hypertension in elderly African American females aged at least 65 years was not found to be correlated with low BMD at either the lumbar spine (L1-L4) or both femoral necks when confounding factors were taken into consideration. Mean BMD of the hypertensive cohort taking thiazide diuretics was found lower at the lumbar spine as compared to the hypertensive patients not taking thiazide diuretics.

Abstract P80: Lack of English Comprehension is Associated with Delays in Hospital Presentation in Patients with ST-Segment Elevation Myocardial Infarction

Background: Prior studies have demonstrated an association between ethnicity and symptom onset to presentation time (S2PT) among patients presenting with ST elevation MI (STEMI) in the USA, with a shorter S2PT among Caucasians when compared with other ethnicities. However, little is known regarding whether or not a patient's ability to comprehend English impacts the S2PT.

Methods: Consecutive patients presenting to 4 hospitals in NYC with STEMI referred for primary angioplasty were included in the analysis. S2PT was recorded on the day of the infarct based on the patient's account of the onset of symptoms. We assessed a patient's ability to comprehend English through telephone interviews conducted during routine follow-up.

Results: Among 210 patients, 83.8% (176 of 210) had either some English comprehension or were fluent in English (E) and 16.2% (34 of 210) reported no English comprehension (non-E). Of the non-E patients, 65% (22 of 34) spoke Spanish, 6% (2 of 34) spoke Russian, 6% (2 of 34) spoke Chinese and 23% (8 of 34) spoke another language. The baseline variables and mean S2PT are depicted in the table. Non-E patients had a significantly higher S2PT compared to E patients even after adjusting for differences in baseline variables. Increased odds were also observed among non-E patients with a longer S2PT (adjusted odds ratio for S2PT > 120 minutes 2.17; 95% CI 01.03-4.54; p=0.04). This association remained constant even after adjusting for confounders like age, sex, ethnicity, level of education and comorbidities (diabetes, previous history of MI and PCI).

Conclusions: S2PT is strongly influenced by a patient's ability to comprehend English. This information emphasizes the need for more aggressive “multi-lingual” educational outreach and the use of multi-lingual emergency lines in an effort to decrease total ischemic time during STEMI.

English Comprehension Fair or Good (N=176) No English Comprehension (N=34) P Age Mean (SD) 62 (14.2) 65 (11) 0.22 Male sex n (%) 129 (73) 26 (76) 0.70 Diabetes n (%) 25 (14) 9 (27) 0.09 Hypertension n (%) 107 (66) 20 (62.5) 0.70 Prior MI n (%) 21 (12) 2 (6) 0.284 Prior PCI or CABG n (%) 12 (6.8) 2 (6) 0.960 Education: n (%) 40 (23) 12 (35) 0.09 Less than HS 62 (35) 8 (23) HS Diploma 8 (4) 0 (0) College Diploma Unknown 66 (38) 14 (42) Mean S2P time (SD) 225 (315) 387 (820.6) 0.05 S2P time > 120 minutes n (%) 70 (40) 20 (62.5) 0.04

Polyomavirus-associated nephropathy: a comparison of 2 different strategies for immunosuppression reduction

Polyomavirus-associated nephropathy (PVAN) is an increasing cause of renal allograft dysfunction, but the optimal management of immunosuppression for these patients is unclear. We examined the clinical course of 58 patients with biopsy-proven PVAN diagnosed from 1997 to 2008 at Johns Hopkins Medical Institutions. Immunosuppression management was analyzed as 2 different immunosuppression reduction strategies, the first centered on eliminating a single immunosuppressive drug and reducing the doses of all other immunosuppressive drugs (Strategy A, n = 40), compared with the second, centered on reducing the doses of all immunosuppressive drugs and eliminating none (Strategy B, n = 18). Primary outcome was graft failure, defined as a 50% reduction in estimated glomerular filtration rate, or the need for dialysis within 2 years of PVAN diagnosis. Graft failure developed in 17 (29%) patients during follow-up. In unadjusted and adjusted Cox models, both strategies of immunosuppression reduction had similar efficacy in preventing graft failure (hazard ratio [HR], 0.61; 95% confidence interval, 0.18-2.06; p = 0.43). Rejection after PVAN occurred in 24 of 58 patients and was associated with a 3-fold higher risk of graft failure (HR, 2.99; p = 0.005). Ancillary therapies (cidofovir or leflunomide) were associated with a trend toward faster clearance of viremia (p = 0.65) but were not predictive of outcome.In conclusion, the 2 strategies of immunosuppression reduction had similar efficacy in preventing graft failure. Post-PVAN rejection leads to graft failure. Early repeat allograft biopsy should be considered in the management of PVAN with persistent graft dysfunction.