Time-Updated Changes in Estimated GFR and Proteinuria and Major Adverse Cardiac Events: Findings from the Chronic Renal Insufficiency Cohort (CRIC) Study.

RATIONALE & OBJECTIVE: Evaluating repeated measures of estimated glomerular filtration rate (eGFR) and urinary protein-creatinine ratio (UPCR) over time may enhance our ability to understand the association between changes in kidney parameters and cardiovascular disease risk. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: Annual visit data from 2,438 participants in the Chronic Renal Insufficiency Cohort (CRIC). EXPOSURES: Average and slope of eGFR and UPCR in time-updated, 1-year exposure windows. OUTCOMES: Incident heart failure, atherosclerotic cardiovascular disease events, death, and a composite of incident heart failure, atherosclerotic cardiovascular disease events, and death. ANALYTICAL APPROACH: A landmark analysis, a dynamic approach to survival modeling that leverages longitudinal, iterative profiles of laboratory and clinical information to assess the time-updated 3-year risk of adverse cardiovascular outcomes. RESULTS: Adjusting for baseline and time-updated covariates, every standard deviation lower mean eGFR (19mL/min/1.73m2) and declining slope of eGFR (8mL/min/1.73m2 per year) were independently associated with higher risks of heart failure (hazard ratios [HRs] of 1.82 [95% CI, 1.39-2.44] and 1.28 [95% CI, 1.12-1.45], respectively) and the composite outcome (HRs of 1.32 [95% CI, 1.11-1.54] and 1.11 [95% CI, 1.03-1.20], respectively). Every standard deviation higher mean UPCR (136mg/g) and increasing UPCR (240mg/g per year) were also independently associated with higher risks of heart failure (HRs of 1.58 [95% CI, 1.28-1.97] and 1.20 [95% CI, 1.10-1.29], respectively) and the composite outcome (HRs of 1.33 [95% CI, 1.17-1.50] and 1.12 [95% CI, 1.06-1.18], respectively). LIMITATIONS: Limited generalizability of annual eGFR and UPCR assessments; several biomarkers for cardiovascular disease risk were not available annually. CONCLUSIONS: Using the landmark approach to account for time-updated patterns of kidney function, average and slope of eGFR and proteinuria were independently associated with 3-year cardiovascular risk. Short-term changes in kidney function provide information about cardiovascular risk incremental to level of kidney function, representing possible opportunities for more effective management of patients with chronic kidney disease.

Novel Risk Factors for Progression of Diabetic and Nondiabetic CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study.

RATIONALE & OBJECTIVE: Identification of novel risk factors for chronic kidney disease (CKD) progression may inform mechanistic investigations and improve identification of high-risk subgroups. The current study aimed to characterize CKD progression across levels of numerous risk factors and identify independent risk factors for CKD progression among those with and without diabetes. STUDY DESIGN: The Chronic Renal Insufficiency Cohort (CRIC) Study is a prospective cohort study of adults with CKD conducted at 7 US clinical centers. SETTING & PARTICIPANTS: Participants (N=3,379) had up to 12.3 years of follow-up; 47% had diabetes. PREDICTORS: 30 risk factors for CKD progression across sociodemographic, behavioral, clinical, and biochemical domains at baseline. OUTCOMES: Study outcomes were estimated glomerular filtration rate (eGFR) slope and the composite of halving of eGFR or initiation of kidney replacement therapy. ANALYTICAL APPROACH: Stepwise selection of independent risk factors was performed stratified by diabetes status using linear mixed-effects and Cox proportional hazards models. RESULTS: Among those without and with diabetes, respectively, mean eGFR slope was-1.4±3.3 and-2.7±4.7mL/min/1.73m2 per year. Among participants with diabetes, multivariable-adjusted hazard of the composite outcome was approximately 2-fold or greater with higher levels of the inflammatory chemokine CXCL12, the cardiac marker N-terminal pro-B-type natriuretic peptide (NT-proBNP), and the kidney injury marker urinary neutrophil gelatinase-associated lipocalin (NGAL). Among those without diabetes, low serum bicarbonate and higher high-sensitivity troponin T, NT-proBNP, and urinary NGAL levels were all significantly associated with a 1.5-fold or greater rate of the composite outcome. LIMITATIONS: The observational study design precludes causal inference. CONCLUSIONS: Strong associations for cardiac markers, plasma CXCL12, and urinary NGAL are comparable to that of systolic blood pressure≥140mm Hg, a well-established risk factor for CKD progression. This warrants further investigation into the potential mechanisms that these markers indicate and opportunities to use them to improve risk stratification.

Slope of Kidney Function and Its Association with Longitudinal Mortality and Cardiovascular Disease among Individuals with CKD.

BACKGROUND: Slopes of eGFR have been associated with increased risks of death and cardiovascular events in a U-shaped fashion. Poor outcomes in individuals with rising eGFR are potentially attributable to sarcopenia, hemodilution, and other indicators of clinical deterioration. METHODS: To investigate the association between eGFR slopes and risks of death or cardiovascular events, accounting for multiple confounders, we studied 2738 individuals with moderate to severe CKD participating in the multicenter Chronic Renal Insufficiency Cohort (CRIC) Study. We used linear, mixed-effects models to estimate slopes with up to four annual eGFR assessments, and Cox proportional hazards models to investigate the association between slopes and the risks of death and cardiovascular events. RESULTS: Slopes of eGFR had a bell-shaped distribution (mean [SD], -1.5 [-2] ml/min per 1.73 m2 per year). Declines of eGFR that were steeper than the average decline associated with progressively increasing risks of death (hazard ratio [HR], 1.23; 95% confidence interval [95% CI], 1.09 to 1.39; for a slope 1 SD below the average) and cardiovascular events (HR, 1.19; 95% CI, 1.03 to 1.38). Rises of eGFR or declines lower than the average decline were not associated with the risk of death or cardiovascular events. CONCLUSIONS: In a cohort of individuals with moderate to severe CKD, we observed steep declines of eGFR were associated with progressively increasing risks of death and cardiovascular events; however, we found no increased risks associated with eGFR improvement. These findings support the potential value of eGFR slopes in clinical assessment of adults with CKD.

A collaborative, individual-level analysis compared longitudinal outcomes across the International Network of Chronic Kidney Disease (iNETCKD) cohorts.

Rates of chronic kidney disease (CKD) progression, end stage kidney disease (ESKD), all-cause mortality, and cardiovascular (CVD) events among individuals with CKD vary widely across countries. Well-characterized demographic, comorbidity, and laboratory markers captured for prospective cohorts may explain, in part, such differences. To investigate whether core characteristics of individuals with CKD explain differences in rates of outcomes, we conducted an individual-level analysis of eight studies that are part of iNET-CKD, an international network of CKD cohort studies. Overall, the rate of CKD progression was 40 events/1000 person-year (95% confidence interval 39 - 41), 28 (27 - 29) for ESKD, 41 (40 - 42) for death, and 29 (28 - 30) for CVD events. However, standardized rates were highly heterogeneous across studies (over 92.5%). Interactions by study group on the association between baseline characteristics and outcomes were then identified. For example, the adjusted hazard ratio for CKD progression was 0.44 (95% confidence interval 0.35 - 0.56) for women vs. men among the Japanese (CKD-JAC), while it was 0.66 (0.59 - 0.75) among the Uruguayan (NRHP). The adjusted hazard ratio for ESKD was 2.02 (95% CI 1.88 - 2.17) per 10 units lower baseline eGFR among Americans (CRIC), while it was 3.01 (2.57 - 3.53) among Canadians (CanPREDDICT) (significant interaction for comparisons across all studies). The risks of CKD progression, ESKD, death, and CVD vary across countries even after accounting for the distributions of age, sex, comorbidities, and laboratory markers. Thus, our findings support the need for a better understanding of specific factors in different populations that explain this variation.

Hematuria as a risk factor for progression of chronic kidney disease and death: findings from the Chronic Renal Insufficiency Cohort (CRIC) Study.

BACKGROUND: Hematuria is associated with chronic kidney disease (CKD), but has rarely been examined as a risk factor for CKD progression. We explored whether individuals with hematuria had worse outcomes compared to those without hematuria in the CRIC Study. METHODS: Participants were a racially and ethnically diverse group of adults (21 to 74 years), with moderate CKD. Presence of hematuria (positive dipstick) from a single urine sample was the primary predictor. Outcomes included a 50% or greater reduction in eGFR from baseline, ESRD, and death, over a median follow-up of 7.3 years, analyzed using Cox Proportional Hazards models. Net reclassification indices (NRI) and C statistics were calculated to evaluate their predictive performance. RESULTS: Hematuria was observed in 1145 (29%) of a total of 3272 participants at baseline. Individuals with hematuria were more likely to be Hispanic (22% vs. 9.5%, respectively), have diabetes (56% vs. 48%), lower mean eGFR (40.2 vs. 45.3 ml/min/1.73 m2), and higher levels of urinary albumin > 1.0 g/day (36% vs. 10%). In multivariable-adjusted analysis, individuals with hematuria had a greater risk for all outcomes during the first 2 years of follow-up: Halving of eGFR or ESRD (HR Year 1: 1.68, Year 2: 1.36), ESRD (Year 1: 1.71, Year 2: 1.39) and death (Year 1:1.92, Year 2: 1.77), and these associations were attenuated, thereafter. Based on NRIs and C-statistics, no clear improvement in the ability to improve prediction of study outcomes was observed when hematuria was included in multivariable models. CONCLUSION: In a large adult cohort with CKD, hematuria was associated with a significantly higher risk of CKD progression and death in the first 2 years of follow-up but did not improve risk prediction.

International Network of Chronic Kidney Disease cohort studies (iNET-CKD): a global network of chronic kidney disease cohorts.

BACKGROUND: Chronic kidney disease (CKD) is a global health burden, yet it is still underrepresented within public health agendas in many countries. Studies focusing on the natural history of CKD are challenging to design and conduct, because of the long time-course of disease progression, a wide variation in etiologies, and a large amount of clinical variability among individuals with CKD. With the difference in health-related behaviors, healthcare delivery, genetics, and environmental exposures, this variability is greater across countries than within one locale and may not be captured effectively in a single study. METHODS: Studies were invited to join the network. Prerequisites for membership included: 1) observational designs with a priori hypotheses and defined study objectives, patient-level information, prospective data acquisition and collection of bio-samples, all focused on predialysis CKD patients; 2) target sample sizes of 1,000 patients for adult cohorts and 300 for pediatric cohorts; and 3) minimum follow-up of three years. Participating studies were surveyed regarding design, data, and biosample resources. RESULTS: Twelve prospective cohort studies and two registries covering 21 countries were included. Participants age ranges from >2 to >70 years at inclusion, CKD severity ranges from stage 2 to stage 5. Patient data and biosamples (not available in the registry studies) are measured yearly or biennially. Many studies included multiple ethnicities; cohort size ranges from 400 to more than 13,000 participants. Studies' areas of emphasis all include but are not limited to renal outcomes, such as progression to ESRD and death. CONCLUSIONS: iNET-CKD (International Network of CKD cohort studies) was established, to promote collaborative research, foster exchange of expertise, and create opportunities for research training. Participating studies have many commonalities that will facilitate comparative research; however, we also observed substantial differences. The diversity we observed across studies within this network will be able to be leveraged to identify genetic, behavioral, and health services factors associated with the course of CKD. With an emerging infrastructure to facilitate interactions among the investigators of iNET-CKD and a broadly defined research agenda, we are confident that there will be great opportunity for productive collaborative investigations involving cohorts of individuals with CKD.

Matrix Metalloproteinase-2 and CKD Progression: The Chronic Renal Insufficiency Cohort (CRIC) Study.

Rationale & Objective: Matrix metalloproteinase 2 (MMP-2) plays an important role in the development of fibrosis, the final common pathway of chronic kidney disease (CKD). This study aimed to assess the relationship between repeated measures of MMP-2 and CKD progression in a large, diverse prospective cohort. Study Design: In a prospective cohort of Chronic Renal Insufficiency Cohort (CRIC) participants (N = 3,827), MMP-2 was measured at baseline. In a case-cohort design, MMP-2 was additionally measured at year 2 in a randomly selected subcohort and cases of estimated glomerular filtration rate (eGFR) halving or kidney replacement therapy (KRT) (N = 1,439). Setting & Participants: CRIC is a multicenter prospective cohort of adults with CKD. Exposure: MMP-2 measured in plasma at baseline and at year 2. Outcomes: A composite kidney endpoint (KRT/eGFR halving). Analytical Approach: Weighted Cox proportional hazards models for case-cohort participants. Results: Participants were followed for a median of 4.6 years from year 2 and 6.9 years from the baseline. Persistently elevated MMP-2 (≥300 ng/mL at both baseline and year 2) increased the hazard of the composite kidney endpoint (HR, 1.61; 95% CI, 1.07-2.42; P = 0.09) after adjusting for covariates. The relationship of persistently elevated MMP-2 was modified by levels of inflammation, with a 2.6 times higher rate of the composite kidney endpoint in those with high-sensitivity C-reactive protein < 2.5 g/dL at study entry. Heterogeneity of effect was found with proteinuria, with a baseline MMP-2 level of ≥300 ng/mL associated with an increased risk of the composite kidney endpoint (HR, 1.30; 95% CI, 1.09-1.54) only with proteinuria ≥ 442 mg/g. Limitations: The observational study design limits causal interpretation. Conclusions: Elevated MMP-2 is associated with CKD progression, particularly among those with low inflammation and those with proteinuria. Future investigations are warranted to confirm the reduction in risk of CKD progression among these subgroups of patients with CKD.

Matrix metalloproteinase 2 (MMP-2) is a matrix-degrading protease involved in fibrosis and elevated in chronic kidney disease (CKD). Longitudinal patterns of MMP-2 have not previously been assessed as a predictor of CKD progression in a large prospective cohort. Here, we found that a higher baseline level and an increasing or persistently elevated 2-year pattern of MMP-2 were associated with CKD progression, independent of all covariates except proteinuria. The association of baseline MMP-2 with CKD progression differed by level of proteinuria, whereas levels of inflammation modified the associations of 2-year MMP-2 patterns with CKD progression.

[Misuse of benzodiazepines: a study among key informants in São Paulo city]. / Uso indevido de benzodiazepínicos: um estudo com informantes-chave no município de São Paulo.

The aim of this study was to understand the practice of prescription, dispensation and prolonged use of benzodiazepines, from the point of view of health care professionals and of chronic users of these substances. The sample group was formed using the snowball technique, totaling 19 key-informants. The semi-structured interviews were recorded and transcribed for analysis. Most of the interviewees reported frequent benzodiazepine prescriptions through requests made to doctors, without the need for a formal appointment. The users reported a history of prolonged use (between 2 and 8 years) for purposes other than the simple therapeutic purpose. They also emphasized the ease in acquiring the medication and the lack of medical counseling about the necessary precautions during treatment. The study suggests that the occurrence of misuse involves not only the dispensation control system, but also a series of other factors, including the attitudes of health care professionals.

Long-term outcomes of elderly kidney transplant recipients.

INTRODUCTION: The number of elderly patients with chronic kidney disease increases progressively, challenging the allocation algorithms in a scenario of organ shortage for transplantation. OBJECTIVE: To evaluate the impact of age on patient and graft survival. METHODS: Evolution of all 366 patients greater than 60 years transplanted between 1998 and 2010 was analyzed versus a control group of 366 younger patients matched for gender, type of donor (living or deceased) and year of transplantation. RESULTS: Diabetes mellitus (HR 1.8; IC 1.2-2.6; p = 0,003) and prioritization (HR 2.9; IC 1.2-2.6; p < 0,001), but not age, were independent factors for kidney graft loss. CONCLUSION: Advanced age was not related to negative outcomes after kidney transplantation, after excluding recipient death as a cause of allograft loss. Higher mortality rate in this group was associated to a higher frequency of comorbidities, especially diabetes mellitus.

Evolução a longo prazo no transplante renal de idosos / Long-term outcomes of elderly kidney transplant recipients

Resumo Introdução: O número de pacientes idosos portadores de doença renal crônica aumenta progressivamente, desafiando os algoritmos de alocação, em um cenário de escassez de órgãos para transplante. Objetivo: Avaliar o impacto da idade sobre os resultados do transplante renal. Métodos: Foram analisados todos os 366 pacientes > 60 anos transplantados entre 1998-2010 versus um grupo controle de 366 pacientes mais jovens pareados por gênero, tipo de doador (vivo/falecido) e ano do transplante. Resultados: Diabetes mellitus (HR 1,5; IC 1,0-2,2; p = 0,031) e doador falecido (HR 1,7; IC 1,2-2,7; p = 0,013) se associaram independentemente a maior risco de óbito. Diabetes mellitus (HR 1,8; IC 1,2-2,6; p = 0,003) e priorização por acesso vascular (HR 2,9; IC 1,2-2,6; p < 0,001), mas não idade, foram fatores independentes de perda do enxerto renal. Conclusão: A idade avançada não teve impacto negativo no resultado do transplante quando excluído óbito do paciente como causa de perda do enxerto. A maior mortalidade entre a população senil esteve associada à maior frequência de comorbidades, em especial diabetes mellitus. .

Abstract Introduction: The number of elderly patients with chronic kidney disease increases progressively, challenging the allocation algorithms in a scenario of organ shortage for transplantation. Objective: To evaluate the impact of age on patient and graft survival. Methods: Evolution of all 366 patients greater than 60 years transplanted between 1998 and 2010 was analyzed versus a control group of 366 younger patients matched for gender, type of donor (living or deceased) and year of transplantation. Results: Diabetes mellitus (HR 1.8; IC 1.2-2.6; p = 0,003) and prioritization (HR 2.9; IC 1.2-2.6; p < 0,001), but not age, were independent factors for kidney graft loss. Conclusion: Advanced age was not related to negative outcomes after kidney transplantation, after excluding recipient death as a cause of allograft loss. Higher mortality rate in this group was associated to a higher frequency of comorbidities, especially diabetes mellitus. .

Uso indevido de benzodiazepínicos: um estudo com informantes-chave no município de São Paulo / Misuse of benzodiazepines: a study among key informants in São Paulo city

Este estudo teve por objetivo compreender a prática de prescrição, dispensação e uso prolongado de benzodiazepínicos, a partir da visão de profissionais de saúde e de usuários crônicos dessas substâncias. A amostra foi composta por técnica de bola de neve, totalizando19 informantes-chave. As entrevistas semi-estruturadas foram gravadas e transcritas para análise. A maioria dos entrevistados relatou ser freqüente a obtenção de prescrição de benzodiazepínicos por solicitações junto aos médicos, sem necessidade de consulta formal. Os usuários relataram histórico de uso prolongado (entre 2 e 8 anos) com finalidades outras que não apenas a terapêutica. Enfatizaram também a facilidade em adquirir a medicação e a falta de orientação médica sobre os cuidados necessários durante o tratamento. O estudo sugere que a ocorrência de uso indevido envolve não apenas o sistema de controle da dispensação, mas uma série de outros fatores, entre os quais as atitudes dos profissionais de saúde.