Association between GFR, proteinuria, and adverse outcomes among White, Chinese, and South Asian individuals in Canada

Differential Associations of Cystatin C Versus Creatinine-Based Kidney Function With Risks of Cardiovascular Event and Mortality Among South Asian Individuals in the UK Biobank

Background South Asian individuals have increased cardiovascular disease and mortality risks. Reliance on creatinine- rather than cystatin C-based estimated glomerular filtration rate (eGFRcys) may underestimate the cardiovascular disease risk associated with chronic kidney disease. Methods and Results Among 7738 South Asian UK BioBank participants without prevalent heart failure (HF) or atherosclerotic cardiovascular disease, we investigated associations of 4 eGFRcys and creatinine-based estimated glomerular filtration rate categories (<45, 45-59, 60-89, and ≥90 mL/min per 1.73 m2) with risks of all-cause mortality, incident HF, and incident atherosclerotic cardiovascular disease. The mean age was 53±8 years; 4085 (53%) were women. Compared with creatinine, cystatin C identified triple the number of participants with estimated glomerular filtration <45 (n=35 versus n=113) and 6 times the number with estimated glomerular filtration 45 to 59 (n=80 versus n=481). After multivariable adjustment, the eGFRcys 45 to 59 category was associated with higher risks of mortality (hazard ratio [HR], 2.38 [95% CI, 1.55-3.65]) and incident HF (sub-HR [sHR], 1.87 [95% CI, 1.09-3.22]) versus the eGFRcys ≥90 category; the creatinine-based estimated glomerular filtration rate 45 to 59 category had no significant associations with outcomes. Of the 7623 participants with creatinine-based estimated glomerular filtration rate ≥60, 498 (6.5%) were reclassified into eGFRcys <60 categories. Participants who were reclassified as having eGFRcys <45 had higher risks of mortality (HR, 4.88 [95% CI, 2.56-9.31]), incident HF (sHR, 4.96 [95% CI, 2.21-11.16]), and incident atherosclerotic cardiovascular disease (sHR, 2.29 [95% CI, 1.14-4.61]) versus those with eGFRcys ≥90; those reclassified as having eGFRcys 45 to 59 had double the mortality risk (HR, 2.25 [95% CI, 1.45-3.51]). Conclusions Among South Asian individuals, cystatin C identified a high-risk chronic kidney disease population that was not detected by creatinine and enhanced estimated glomerular filtration rate-based risk stratification for mortality, incident HF, and incident atherosclerotic cardiovascular disease.

Evidence-Based Decision Making 6: Administrative Databases as Secondary Data Source for Epidemiologic and Health Service Research

Health-care systems require reliable information on which to base health-care planning and make decisions, as well as to evaluate their policy impact. Administrative data, predominantly captured for non-research purposes, provide important information about health services use, expenditures, and clinical outcomes and may be used to assess quality of care. With increased digitalization and accessibility of administrative databases, this data is more readily available for health service research purposes, aiding evidence-based decision making. This chapter discusses the utility of administrative data for population-based studies of health and health care.

Efficacy and safety of Shenyankangfu Tablet, a Chinese patent medicine, for primary glomerulonephritis: A multicenter randomized controlled trial

BACKGROUND

Shenyankangfu Tablet (SYKFT) is a Chinese patent medicine that has been used widely to decrease proteinuria and the progression of chronic kidney disease.

OBJECTIVE

This trial compared the efficacy and safety of SYKFT, for the control of proteinuria in primary glomerulonephritis patients, against the standard drug, losartan potassium.

DESIGN, SETTING, PARTICIPANTS AND INTERVENTION

This was a multicenter, double-blind, randomized, controlled clinical trial. Primary glomerulonephritis patients, aged 18-70 years, with blood pressure ≤ 140/90 mmHg, estimated glomerular filtration rate (eGFR) ≥ 45 mL/min per 1.73 m², and 24-hour proteinuria level of 0.5-3.0 g, were recruited in 41 hospitals across 19 provinces in China and were randomly divided into five groups: SYKFT, losartan potassium 50 mg or 100 mg, SYKFT plus losartan potassium 50 mg or 100 mg.

MAIN OUTCOME MEASURES

The primary outcome was change in the 24-hour proteinuria level, after 48 weeks of treatment.

RESULTS

A total of 735 participants were enrolled. The percent decline of urine protein quantification in the SYKFT group after 48 weeks was 8.78% ± 2.56% (P = 0.006) more than that in the losartan 50 mg group, which was 0.51% ± 2.54% (P = 1.000) less than that in the losartan 100 mg group. Compared with the losartan potassium 50 mg group, the SYKFT plus losartan potassium 50 mg group had a 13.39% ± 2.49% (P < 0.001) greater reduction in urine protein level. Compared with the losartan potassium 100 mg group, the SYKFT plus losartan potassium 100 mg group had a 9.77% ± 2.52% (P = 0.001) greater reduction in urine protein. With a superiority threshold of 15%, neither was statistically significant. eGFR, serum creatinine and serum albumin from the baseline did not change statistically significant. The average change in TCM syndrome score between the patients who took SYKFT (-3.00 [-6.00, -2.00]) and who did not take SYKFT (-2.00 [-5.00, 0]) was statistically significant (P = 0.003). No obvious adverse reactions were observed in any group.

CONCLUSION

SYKFT decreased the proteinuria and improved the TCM syndrome scores of primary glomerulonephritis patients, with no change in the rate of decrease in the eGFR. SYKFT plus losartan potassium therapy decreased proteinuria more than losartan potassium therapy alone.

TRIAL REGISTRATION NUMBER

NCT02063100 on ClinicalTrials.gov.

Ethnic minority disparities in progression and mortality of pre-dialysis chronic kidney disease: a systematic scoping review

Background

There are a growing number of studies on ethnic differences in progression and mortality for pre-dialysis chronic kidney disease (CKD), but this literature has yet to be synthesised, particularly for studies on mortality.

Methods

This scoping review synthesized existing literature on ethnic differences in progression and mortality for adults with pre-dialysis CKD, explored factors contributing to these differences, and identified gaps in the literature. A comprehensive search strategy using search terms for ethnicity and CKD was taken to identify potentially relevant studies. Nine databases were searched from 1992 to June 2017, with an updated search in February 2020.

Results

8059 articles were identified and screened. Fifty-five studies (2 systematic review, 7 non-systematic reviews, and 46 individual studies) were included in this review. Most were US studies and compared African-American/Afro-Caribbean and Caucasian populations, and fewer studies assessed outcomes for Hispanics and Asians. Most studies reported higher risk of CKD progression in Afro-Caribbean/African-Americans, Hispanics, and Asians, lower risk of mortality for Asians, and mixed findings on risk of mortality for Afro-Caribbean/African-Americans and Hispanics, compared to Caucasians. Biological factors such as hypertension, diabetes, and cardiovascular disease contributed to increased risk of progression for ethnic minorities but did not increase risk of mortality in these groups.

Conclusions

Higher rates of renal replacement therapy among ethnic minorities may be partly due to increased risk of progression and reduced mortality in these groups. The review identifies gaps in the literature and highlights a need for a more structured approach by researchers that would allow higher confidence in single studies and better harmonization of data across studies to advance our understanding of CKD progression and mortality.

Impact of Kidney Function on Cardiovascular Risk and Mortality: A Comparison of South Asian and European Cohorts

BACKGROUND

Evidence is limited on ethnic differences in associations between kidney function markers and mortality or cardiovascular disease (CVD).

METHODS

Baseline cross-sectional analysis and longitudinal follow-up study of a UK population-based cohort of 1,116 Europeans and 1,104 South Asians of predominantly Indian descent, age 52 ± 7 years at baseline (1988-1991). Kidney function was estimated using Cystatin C and creatinine-based chronic kidney disease (CKD) Epidemiology Collaboration estimated glomerular filtration rate (eGFR) equations, and urinary albumin-creatinine ratio (ACR). Mortality was captured at 27 years, and incident CVD at 22 years, from death certification, medical records and participant report. Longitudinal associations between eGFR/ACR and mortality/incident CVD were examined using Cox models.

RESULTS

eGFRcys was lower and ACR higher in South Asians than Europeans. eGFRcys and -eGFRcreat were more strongly associated with outcomes in Europeans than South Asians. Conversely, associations between ACR and outcomes were greater in South Asians than Europeans, for example, for CVD mortality: HRs (95% CI) adjusted for CVD risk factors and ACR/eGFRcys as appropriate, p for ethnicity interaction: eGFRcys: Europeans: 0.76 (0.62-0.92), South Asians: 0.92 (0.78-1.07), p = 0.05, eGFRcreat: Europeans 0.81 (0.67-0.99), South Asians 1.18 (0.97-1.41), p = 0.002, ACR: -Europeans: 1.24 (1.08-1.42), South Asians: 1.39 (1.25-1.57), p= 0.23. Addition of all CKD measures to a standard CVD risk factor model modestly improved prediction capability in -Europeans; in South Asians only ACR contributed to improvement.

CONCLUSIONS

Strong associations between ACR and outcomes in South Asians of predominantly Indian origin, and null associations for eGFRcys and eGFRcreat, suggest that ACR may have greater utility in CVD risk prediction in South Asians. Further work is needed to validate these -findings.

Validation of Self-Reported Race in a Canadian Provincial Renal Administrative Database

Background:

Administrative data are commonly used to study clinical outcomes in renal disease. Race is an important determinant of renal health delivery and outcomes in Canada but is not validated in most administrative data, and the correlation with census-based definitions of race is unknown.

Objectives:

Validation of self-reported race (SRR) in a Canadian provincial renal administrative database (Patient Records and Outcome Management Information System [PROMIS]) and comparison with the Canadian census categories of race.

Design:

Prospective patient survey study to validate SRR in PROMIS.

Setting:

British Columbia, Canada.

Patients:

Adult patients registered in PROMIS.

Measurements:

Survey SRR was used as gold standard to validate SRR in PROMIS. Self-reported race in PROMIS was compared with census race categories.

Methods:

This is a cross-sectional telephone survey of a random sample of all adults in PROMIS conducted between February 2016 and November 2016. Responders selected a race category from PROMIS and from the Canadian census. Sensitivity (Sn) and specificity (Sp) were calculated with 95% confidence intervals (CIs).

Results:

A total of 21 039 patients met inclusion criteria, 1677 were selected for the survey and 637 participated (38% response rate). There were no differences between the PROMIS, sampled, and responder populations. PROMIS SRR had an accuracy of 95.3% (95% CI: 94.2%-97.0%) when validated against the survey SRR with Sn and Sp ≥90% in all race groups except in Aboriginals (Sn 87.5%). The positive and negative predictive values were ≥95%, except in very low and high–prevalence groups, respectively. The Canadian census had an accuracy of 95.7% (95% CI: 94.4%-97.6%) when validated against PROMIS SRR with Sn and Sp ≥90%. The results did not differ in subgroups based on age, sex, birth outside Canada, or renal group (glomerulonephritis, chronic kidney disease, hemodialysis, peritoneal dialysis, transplant recipients, or live donors).

Limitations:

Analysis of minority groups and lower prevalence groups is limited by sample size. Results may not be generalizable to other administrative databases.

Conclusions:

We have shown high accuracy of PROMIS SRR that validates its use in the secondary analysis of administrative data for research. There is high correlation between PROMIS and census race categories which allows linkage with other data sources that use census-based definitions of race.

Association of estimated glomerular filtration rate and proteinuria with all-cause mortality in community-based population in China: A Result from Kailuan Study

This study was based on 95391 participants (18-98 years old) from the Kailuan study, which assessed all-cause mortality in a community-based population in northern China according to estimated glomerular filtration rate (eGFR) by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula and proteinuria estimated from urine dipstick results. Data were analysed based on Cox proportional hazards models with adjustment for relevant confounders, and the results were expressed as hazard ratios (HRs) with 95% confidence intervals (CIs). During eight years of follow-up, a total of 6024 participants died. The two indicators, eGFR < 45 ml/min/1.73 m² and the presence of proteinuria, were independently associated with all-cause mortality. Compared with eGFR ≥45 ml/min/1.73 m² with negative proteinuria, HRs of all-cause mortality were 1.26 (95% CI 1.10-1.44) for eGFR < 45 ml/min/1.73 m² without proteinuria, 1.95 (1.78-2.14) for eGFR ≥45 ml/min/1.73 m² with proteinuria, and 2.63 (2.14-3.23) for eGFR < 45 ml/min/1.73 m² with proteinuria. The all-cause mortality risk of eGFR and/or proteinuria was much higher in females than in males (P for interaction < 0.01). In conclusion, both severely decreased eGFR and proteinuria are independent predictors of all-cause mortality in the general northern Chinese population. A combination of severely decreased eGFR and proteinuria increases the risk of all-cause mortality, which is even over 5-fold higher in females.

Progression and outcomes of non-dialysis dependent chronic kidney disease patients: A single center longitudinal follow-up study

AIM

Despite increase global prevalence of End stage renal disease (ESRD) and subsequent need for renal replacement therapy (RRT), relatively little is known about disease progression and prognosis of earlier stages of CKD. Current study was conducted to examine rate of CKD progression, predictors of ESRD and death.

METHODS

A total 621 patients with estimated glomerular filtration rate (eGFR) of 15-59ml/min/1.73m² (CKD stage 3 & 4) were selected and followed up for 10 years or until ESRD or death, whichever occurred first. Subjects who did not meet inclusion criteria were excluded (n=1474).

RESULTS

Annual cumulative decline in eGFR was 3.01±0.40 ml/min/1.73m² . Overall disease progression was observed in 60% patients while 18% died. Among patients with CKD stage 3, 21% progressed to stage 4, 10% to stage 5ND (non-dialysis) and 31% to RRT while mortality was observed in 16% patients. On the other hand, 8% patients with CKD stage 4 progressed to stage 5ND, 31% to RRT and mortality was observed in 24% cases. Patients with CVD, higher systolic blood pressure, elevated phosphate levels, heavy proteinuria, microscopic hematuria and use of diuretics were more likely to develop ESRD. Advancing age, low eGFR, low systolic blood pressure, low hemoglobin and baseline diabetes were found to be significant predictors of mortality while being female reduced risk of mortality.

CONCLUSION

Our data suggest that, in this CKD cohort, patients were more likely to develop ESRD than death. Prime importance should be given to mild forms of CKD to retard and even reverse CKD progression.

The Glomerular Filtration Rate (GFR) at Dialysis Initiation and Mortality in Chronic Kidney Disease (CKD) in East Asian Populations: A Meta-analysis

Objective The impact of dialysis initiation on survival is still somewhat controversial. Given that race or ethnicity has been observed to be a predictor of mortality and the rate of progression of chronic kidney disease, we conducted a meta-analysis to investigate the effect of early vs. late dialysis initiation on mortality in East Asian populations. Methods All eligible cohort studies of target were selected from the MEDLINE (PubMed), EMBASE, The Cochrane Library and the Clinical Trials Registry databases from inception to October 2014. The data were extracted with all-cause mortality rates as the primary outcome, and pooled adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. Results Ten studies examined the association between early vs. late dialysis initiation and mortality. Compared to late dialysis initiation, patients who received early dialysis initiation had a higher overall mortality risk (adjusted HR, 1.36; 95% CI, 1.0-1.85; p<0.05) in East Asian populations. In a subgroup analysis, baseline characteristic differences (adjusted HR, 2.0; 95%CI, 1.56-2.57; p<0.001), initial dialysis modalities (adjusted HR, 2.12; 95% CI, 1.72-2.62; p<0.001) and follow up duration (adjusted HR, 1.59; 95% CI, 1.19-2.12; p=0.002), demonstrated that the association between early dialysis initiation and mortality were significant. Conclusion A higher glomerular filtration rate (early) at the initiation of dialysis is associated with a higher all-cause mortality risk in East Asian populations.

Mortality and Renal Replacement Therapy after Renal Artery Stent Placement for Atherosclerotic Renovascular Disease

PURPOSE

To identify risk factors for progression to renal replacement therapy (RRT) and all-cause mortality in patients who underwent renal artery (RA) stent placement for atherosclerotic renal artery stenosis (RAS).

MATERIALS AND METHODS

A retrospective study from June 1996 to June 2009 identified 1,052 patients who underwent RA stent placement. Glomerular filtration rate at time of RA stent placement was estimated from serum creatinine level and divided into chronic kidney disease (CKD) stages 1-5. Univariate and multivariable Cox proportional hazards models were used to determine which factors were associated with each endpoint.

RESULTS

Times to progression to all-cause mortality and RRT were similar for CKD stages 1/2/3A and served as the reference group. In multivariable analysis, high-grade proteinuria (P < .001) and higher CKD stage (5 vs 1/2/3A [P < .001], 4 vs 1/2/3A [P < .001], 3B vs 1/2/3A [P = .02]) remained independently associated with increased risk of progression to RRT. Angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) use was associated with decreased risk of progression to RRT (P = .03). Higher CKD stage (5 vs 1/2/3A [P < .001], 4 vs 1/2/3A [P = .004]), carotid artery disease (P < .001), diabetes mellitus (P = .002), and high-grade proteinuria (P < .001) remained independently associated with all-cause mortality. Statin use was associated with decreased risk of all-cause mortality (P < .001).

CONCLUSIONS

Patients with atherosclerotic RAS who undergo RA stent placement and have high-grade proteinuria and CKD stage 3B/4/5 have increased risk of progression to RRT. Patients with high-grade proteinuria, CKD stage 3B/4/5, carotid artery disease, or diabetes have increased risk for all-cause mortality after renal artery stent placement. Patients receiving ACEI/ARBs have a decreased risk of progression to RRT, and patients receiving statins have a decreased risk of all-cause mortality.

Ethnic Differences in Prevalence of Peripheral Artery Disease in Patients Undergoing Hemodialysis

BACKGROUND

Hemodialysis patients experience poor outcomes associated with the presence of atherosclerosis, particularly lower-extremity peripheral artery disease (PAD). Prevalence of PAD is known to vary between ethnic groups; however, no information on ethnic-specific PAD prevalence in a hemodialysis cohort is available.

METHODS

Data from the Canadian Kidney Dialysis Cohort Study was used in a secondary analysis of 1293 adults starting hemodialysis in three major Canadian centres. PAD diagnosis was determined through structured interview and supplemented by clinical record. Ethnicity was self-reported.

RESULTS

Overall PAD prevalence was 19.1 % with no significant difference between ethnic groups. Ethnic differences observed in diabetes prevalence in the full hemodialysis group were not present in the subset of PAD patients.

CONCLUSIONS

The prevalence of PAD in patients undergoing hemodialysis is high, however we found no apparent ethnic differences in prevalence between ethnic groups.

The impact of social disadvantage in moderate-to-severe chronic kidney disease: an equity-focused systematic review*

It is unclear whether a social gradient in health outcomes exists for people with moderate-to-severe chronic kidney disease (CKD). We critically review the literature for evidence of social gradients in health and investigate the ‘suitability’ of statistical analyses in the primary studies. In this equity-focused systematic review among adults with moderate-to-severe CKD, factors of disadvantage included gender, race/ethnicity, religion, education, socio-economic status or social capital, occupation and place of residence. Outcomes included access to healthcare, kidney disease progression, cardiovascular events, all-cause mortality and suitability of analyses. Twenty-four studies in the pre-dialysis population and 34 in the dialysis population representing 8.9 million people from 10 countries were included. In methodologically suitable studies among pre-dialysis patients, a significant social gradient was observed in access to healthcare for those with no health insurance and no home ownership. Low income and no home ownership were associated with higher cardiovascular event rates and higher mortality [HR 1.94, 95% confidence interval (CI) 1.27–2.98; HR 1.28, 95% CI 1.04–1.58], respectively. In methodologically suitable studies among dialysis patients, females, ethnic minorities, those with low education, no health insurance, low occupational level or no home ownership were significantly less likely to access cardiovascular healthcare than their more advantaged dialysis counterparts. Low education level and geographic remoteness were associated with higher cardiovascular event rates and higher mortality (HR 1.54, 95% CI 1.01–2.35; HR 1.21, 95% CI 1.08–1.37), respectively. Socially disadvantaged pre-dialysis and dialysis patients experience poorer access to specialist cardiovascular health services, and higher rates of cardiovascular events and mortality than their more advantaged counterparts.

Epidemiological study of chronic kidney disease progression: a large-scale population-based cohort study

The prognostic information about CKD progression, particularly for GFR categories 1 and 2, is still limited. This cohort was therefore conducted to determine the CKD progression using a competing risk approach. We conducted a retrospective cohort study linking community health screening with hospitals and death registry data in a province of Thailand, from 1997 to 2011. A competing risk model was applied by treating death as a competing risk factor to estimate 2-, 5-, and 10-year probability of kidney failure and median time for CKD progression from lower to higher GFR category. There were 17,074 non-diabetic and 15,032 diabetic CKD subjects. Diabetic subjects progressed more rapidly through GFR categories with the median times for CKD progression from GFR categories G1 to G2, G2 to G3a, G3a to G3b, G3b to G4, and G4 to G5 of 4.4, 6.1, 4.9, 6.3, and 9.0 years, respectively. Non-diabetic subjects took longer to progress with the corresponding median time of 9.4, 14.0, 11.0, 13.8, and >14.3 years. After adjusting for confounders, diabetic subjects were 49% (cause-specific hazard ratio ((c)HR) = 1.49, 95% CI: 1.37, 1.62) more likely to develop kidney failure than non-diabetic subjects. Albuminuria categories A3 and A2 were, respectively, 3.40 (95% CI: 3.07, 3.76) and 1.71 (95% CI: 1.53, 1.92) higher risk of kidney failure when compared to A1. For each albumin category, death rate increased as albuminuria increased particularly in diabetic subjects, which was approximately 2 times higher in A3 compared to A1. Considering GFR category, it gradually increased from G1 to G4 and sharply increased from G4 to G5 in both non-diabetic and diabetic subjects. This study has quantified CKD progression in an Asian population within ordinary practice. Diabetic subjects progress through GFR and albuminuria categories and reach kidney failure about twice as rapidly as non-diabetic subjects.

Evidence-based decision-making 6: Utilization of administrative databases for health services research

Health-care systems require reliable information on which to base health-care planning and make decisions, as well as to evaluate their policy impact. Administrative data provide important information about health services use, expenditures, clinical outcomes, and may be used to assess quality of care. With increased digitalization and accessibility of administrative databases, these data are more readily available for health service research purposes, aiding evidence-based decision-making. This chapter discusses the utility of administrative data for population-based studies of health and health care.

Efficacy and safety of Shenyankangfu tablets for primary glomerulonephritis: study protocol for a randomized controlled trial

BACKGROUND

Chronic kidney disease is a common disease. Most chronic kidney diseases evolve from primary glomerulonephritis. Proteinuria is an independent risk factor for the progression of chronic kidney disease. The general consensus is that therapy administered to decrease proteinuria should include steroids and/or immunosuppressants, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers. However, the side effects of, and adverse reactions to, these agents reduce the benefits to patients. In addition, the cost of these drugs is relatively high. Therefore, identification of inexpensive and effective drugs to decrease proteinuria is urgently needed. Shenyankangfu tablets have been a widely applied Chinese patent medicine for many years to decrease proteinuria. However, there is a lack of research-derived data regarding the clinical use. Therefore, we designed the present randomized controlled clinical trial to compare the efficacy and safety of Shenyankangfu tablets versus losartan potassium for control of proteinuria in patients with primary glomerulonephritis.

METHODS/DESIGN

This study will be a multicenter, prospective, double-blind, double-dummy, randomized controlled clinical trial. We will enroll 720 patients diagnosed with primary glomerulonephritis. The eligible patients will be randomly divided into the following groups at a 1:1:1:1:1 ratio: Shenyankangfu tablets group, losartan potassium 50 mg group, losartan potassium 100 mg group, Shenyankangfu tablets + losartan potassium 50 mg group, and Shenyankangfu tablets + losartan potassium 100 mg group. All groups will be followed up for 48 weeks; follow-up visits will be performed, at weeks 0, 4, 8, 12, 24, 36, and 48. The primary efficacy outcome will be the post-treatment change in the 24-hour proteinuria level, and the secondary efficacy outcomes will be the post-treatment changes in the serum creatinine level, estimated glomerular filtration rate, traditional Chinese medicine syndrome score, and serum albumin level.

DISCUSSION

The results of this trial will provide solid data for use in evidence-based medicine with respect to the efficacy and safety of Shenyankangfu tablets for control of proteinuria in patients with primary glomerulonephritis compared to those of losartan potassium. Moreover, we infer that therapy comprising Shenyankangfu tablets + losartan potassium can decrease proteinuria to a larger extent than Shenyankangfu tablets or losartan potassium can alone.

TRIAL REGISTRATION

This trial was registered on 12 February 2014 at ClinicalTrials.gov (ID number NCT02063100).

Relative risks of chronic kidney disease for mortality and end-stage renal disease across races are similar

Some suggest race-specific cutpoints for kidney measures to define and stage chronic kidney disease (CKD), but evidence for race-specific clinical impact is limited. To address this issue, we compared hazard ratios of estimated glomerular filtration rates (eGFR) and albuminuria across races using meta-regression in 1.1 million adults (75% Asians, 21% Whites, and 4% Blacks) from 45 cohorts. Results came mainly from 25 general population cohorts comprising 0.9 million individuals. The associations of lower eGFR and higher albuminuria with mortality and end-stage renal disease (ESRD) were largely similar across races. For example, in Asians, Whites, and Blacks, the adjusted hazard ratios (95% confidence interval) for eGFR 45-59 versus 90-104 ml/min per 1.73 m(2) were 1.3 (1.2-1.3), 1.1 (1.0-1.2), and 1.3 (1.1-1.7) for all-cause mortality, 1.6 (1.5-1.7), 1.4 (1.2-1.7), and 1.4 (0.7-2.9) for cardiovascular mortality, and 27.6 (11.1-68.7), 11.2 (6.0-20.9), and 4.1 (2.2-7.5) for ESRD, respectively. The corresponding hazard ratios for urine albumin-to-creatinine ratio 30-299 mg/g or dipstick 1+ versus an albumin-to-creatinine ratio under 10 or dipstick negative were 1.6 (1.4-1.8), 1.7 (1.5-1.9), and 1.8 (1.7-2.1) for all-cause mortality, 1.7 (1.4-2.0), 1.8 (1.5-2.1), and 2.8 (2.2-3.6) for cardiovascular mortality, and 7.4 (2.0-27.6), 4.0 (2.8-5.9), and 5.6 (3.4-9.2) for ESRD, respectively. Thus, the relative mortality or ESRD risks of lower eGFR and higher albuminuria were largely similar among three major races, supporting similar clinical approach to CKD definition and staging, across races.

Effect of dialysis initiation timing on clinical outcomes: a propensity-matched analysis of a prospective cohort study in Korea

BACKGROUND

Controversy persists regarding the appropriate initiation timing of renal replacement therapy for patients with end-stage renal disease. We evaluated the effect of dialysis initiation timing on clinical outcomes. Initiation times were classified according to glomerular filtration rate (GFR).

METHODS

We enrolled a total of 1691 adult patients who started dialysis between August 2008 and March 2013 in a multi-center, prospective cohort study at the Clinical Research Center for End Stage Renal Disease in the Republic of Korea. The patients were classified into the early-start group or the late-start group according to the mean estimated GFR value, which was 7.37 ml/min/1.73 m2. The primary outcome was patient survival, and the secondary outcomes were hospitalization, cardiovascular events, vascular access complications, change of dialysis modality, and peritonitis. The two groups were compared before and after matching with propensity scores.

RESULTS

Before propensity score matching, the early-start group had a poor survival rate (P<0.001). Hospitalization, cardiovascular events, vascular access complications, changes in dialysis modality, and peritonitis were not different between the groups. A total of 854 patients (427 in each group) were selected by propensity score matching. After matching, neither patient survival nor any of the other outcomes differed between groups.

CONCLUSIONS

There was no clinical benefit after adjustment by propensity scores comparing early versus late initiation of dialysis.

The long-term impact of eGFR reporting on referral patterns

BACKGROUND

The prognostic significance of CKD has driven the widespread introduction of automated estimated glomerular filtration rate (eGFR) reporting, and the incorporation of CKD in the revised Quality Outcomes Framework (QOF) of the General Medical Services (GMS) contract in the U.K.

AIMS

To assess the long-term impact of the introduction of these two initiatives, on patient referral numbers to a nephrology service.

METHODS

Data was collected on the numbers and basic characteristics of all new patients referred from April 2005 to March 2011, to one NHS Health Board.

RESULTS

Introduction of eGFR reporting and CKD QOF domains was associated with a significant increase in the number of referrals, which was sustained. The initiatives also led to a sustained increase in the mean age of the patients at referral, predominantly due to an increase in the age of female patients referred. There was also an increase in the proportion of female patients referred. In the immediate aftermath of the introduction of change there was a transient decrease in the average eGFR at referral, a decrease in age of patients referred with an eGFR <15ml/min and an increase in the eGFR of patients >70yrs of age.

CONCLUSIONS

The data demonstrates significant and sustained increase in numbers of referrals. In the short term this was associated with a reduction in referral of elderly patients with stage 5 CKD and an increase in elderly patients with mild renal impairment. In the longer term we saw an increase in referral of an older female population.

Incremental prognostic information from kidney function in patients with new onset coronary heart disease

BACKGROUND

Prognostic factors are usually evaluated by their statistical significance rather than by their clinical utility. Risk reclassification measures the extent to which a novel marker adds useful information to a prognostic model. The extent to which estimated glomerular filtration rate (eGFR) adds information about prognosis among patients with coronary heart disease is uncertain.

METHODS

We studied patients in an integrated health care delivery system with newly diagnosed coronary heart disease. We developed a model of the risk of death over 2 years of follow-up and then added eGFR to the model and measured changes in C-index, net reclassification improvement, and integrated discrimination improvement.

RESULTS

Almost half of the 31,533 study patients had reduced eGFR (<60 mL/min per 1.73 m(2)). Mortality was significantly higher among patients who had lower levels of eGFR, even after adjustment for baseline characteristics (P < .0001). The addition of eGFR to the prognostic model increased the C-index from 0.837 to 0.843, the net reclassification improvement by 3.2% (P < .0001), and integrated discrimination improvement by 1.3% (P = .007).

CONCLUSION

Estimated glomerular filtration rate is an informative prognostic factor among patients with incident coronary heart disease, independent of other clinical characteristics.

The impact of chronic kidney disease and cardiovascular comorbidity on mortality in a multiethnic population: a retrospective cohort study

OBJECTIVE

To assess the impact of chronic kidney disease (CKD) and cardiovascular comorbidity on mortality in a multiethnic primary care population.

DESIGN

Retrospective cohort study.

SETTING

Inner-city primary care trust in West Midlands, UK.

PARTICIPANTS

Individuals aged 40 years and older, of South Asian, black or white ethnicity, registered with a general practice and with their kidney function checked within the last 12 months (n=31 254).

OUTCOME MEASURE

All-cause mortality.

RESULTS

Reduced estimated glomerular filtration rate, higher albuminuria, older age, white ethnicity (vs South Asian or black ethnicity) and increasing cardiovascular comorbidities were independent determinants of a higher mortality risk. In the multivariate model including comorbidities and kidney function, the HR for mortality for South Asians was 0.697 (95% CI 0.56 to 0.868, p=0.001) and for blacks it was 0.533 (95% CI 0.403 to 0.704, p<0.001) compared to whites.

CONCLUSIONS

The HR for death is lower for South Asian and black individuals compared to white individuals. This is, in part, independent of age, gender, socioeconomic status, kidney function and comorbidities. Risk of death is higher in individuals with CKD and with a higher cumulative cardiovascular comorbidity.