Association of Glycemic Status During Progression of Chronic Kidney Disease With Early Dialysis Mortality in Patients With Diabetes

Safety of SGLT2 inhibitors, DPP-4 inhibitors, and GLP-1 receptor agonists in US veterans with and without chronic kidney disease: a population-based study

Background

We examined the real-world comparative safety of sodium-glucose cotransporter-2 inhibitors (SGLT2i) vs. other newer anti-glycemic medications (dipeptidyl peptidase-4 inhibitors [DPP4i], glucagon-like peptide-1 receptor agonists [GLP1a]) in patients with and without chronic kidney disease (CKD).

Methods

Among US Veterans with diabetes receiving care from the Veterans Affairs (VA) healthcare system over 2004-19, we identified incident users of SGLT2i vs. DPP4i vs. GLP1a monotherapy. In analyses stratified by CKD status, defined by estimated glomerular filtration rate and albuminuria, we examined associations of SGLT2i vs. DPP4i vs. GLP1a use with risk of infection-related (primary outcome) and genitourinary infection hospitalizations (secondary outcome) using multivariable Cox models.

Findings

Among 92,269 patients who met eligibility criteria, 52% did not have CKD, whereas 48% had CKD. In the overall and non-CKD cohorts, compared to DPP4i use, SGLT2i use was associated with lower infection-related hospitalization risk (HRs [95% CIs] 0.74 [0.67-0.81] and 0.77 [0.67, 0.88], respectively), whereas GLP1a use demonstrated comparable risk. However, in the CKD cohort SGLT2i and GLP1a use were each associated with lower risk (HRs [95% CIs] 0.70 [0.61, 0.81] and 0.91 [0.84, 0.99], respectively). Propensity score-matched analyses showed similar findings in the non-CKD and CKD cohorts. In the overall, non-CKD, and CKD cohorts, SGLT2i use was associated with lower genitourinary infection hospitalization risk whereas GLP1a use showed comparable risk vs. DPP4i use.

Interpretation

In a national cohort of Veterans with diabetes, compared with DPP4i use, SGLT2i use was associated with lower infection-related and genitourinary infection hospitalization risk.

Funding

VA Health Services Research and Development, USA.

One-Year Efficacy and Safety of Dulaglutide in Patients With Type 2 Diabetes and Chronic Kidney Disease: A Retrospective Study of Asian Patients

PURPOSE

Dulaglutide is a long-acting glucagon-like peptide-1 receptor agonist that is not cleared by the kidneys and has proven efficacy and safety in patients with diabetic kidney disease. We aimed to evaluate the 1-year efficacy of dulaglutide in patients with diabetic kidney disease who have used the drug for more than 1 year.

METHODS

This retrospective, observational study comprised 131 patients with an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m2 who had received dulaglutide for more than one year between June 2016 and May 2023. The primary outcome measures were changes in glycosylated hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and body weight from baseline to the 12-month follow-up, with assessments performed at six-month intervals. Subgroup analyses were conducted based on age, sex, baseline body mass index, FPG, and HbA1c, and insulin administration at baseline and last follow-up.

FINDINGS

The mean age was 60.0 ± 10.2 years, and 61.1% of the participants were males. Baseline HbA1c, FPG, and body weight were 9.1% (76.0 mmol/mol), 186.8 mg/dL, and 79.3 kg, respectively. Dulaglutide significantly reduced HbA1c, FPG, and body weight from baseline to the 12-month follow-up (mean ± standard error: -1.2 ± 0.1%, -34.8 ± 6.9 mg/dL, and -2.3 ± 0.5 kg, respectively; P < 0.001). Subgroup analysis revealed significant differences in HbA1c reduction based on baseline HbA1c.

IMPLICATIONS

Dulaglutide exhibited sustained glucose-lowering and weight-reduction effects during the initial 1 year of treatment in patients with diabetic kidney disease. Altogether, dulaglutide could serve as a favorable long-term therapeutic option for patients with diabetic kidney disease in real-world clinical settings.

Use of Analog and Human Insulin in a European Hemodialysis Cohort With Type 2 Diabetes: Associations With Mortality, Hospitalization, MACE, and Hypoglycemia

RATIONALE & OBJECTIVE

Poor glycemic control may contribute to the high mortality rate in patients with type 2 diabetes receiving hemodialysis. Insulin type may influence glycemic control, and its choice may be an opportunity to improve outcomes. This study assessed whether treatment with analog insulin compared with human insulin is associated with different outcomes in people with type 2 diabetes and kidney failure receiving hemodialysis.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

People in the Analyzing Data, Recognizing Excellence and Optimizing Outcomes (AROii) study with kidney failure commencing hemodialysis and type 2 diabetes being treated with insulin within 288 dialysis facilities between 2007 and 2009 across 7 European countries. Study participants were followed for 3 years. People with type 1 diabetes were excluded using an established administrative data algorithm.

EXPOSURE

Treatment with an insulin analog or human insulin.

OUTCOME

All-cause mortality, major adverse cardiovascular events (MACE), all-cause hospitalization, and confirmed hypoglycemia (blood glucose<3.0mmol/L sampled during hemodialysis).

ANALYTICAL APPROACH

Inverse probability weighted Cox proportional hazards models to estimate hazard ratios for analog insulin compared with human insulin.

RESULTS

There were 713 insulin analog and 733 human insulin users. Significant variation in insulin type by country was observed. Comparing analog with human insulin at 3 years, the percentage of patients experiencing end points and adjusted hazard ratios (AHR) were 22.0% versus 31.4% (AHR, 0.808 [95% CI, 0.66-0.99], P=0.04) for all-cause mortality, 26.8% versus 35.9% (AHR, 0.817 [95% CI, 0.68-0.98], P=0.03) for MACE, and 58.2% versus 75.0% (AHR, 0.757 [95% CI, 0.67-0.86], P<0.001) for hospitalization. Hypoglycemia was comparable between insulin types at 14.1% versus 15.0% (AHR, 1.169 [95% CI, 0.80-1.72], P=0.4). Consistent strength and direction of the associations were observed across sensitivity analyses.

LIMITATIONS

Residual confounding, lack of more detailed glycemia data.

CONCLUSIONS

In this large multinational cohort of people with type 2 diabetes and kidney failure receiving maintenance hemodialysis, treatment with analog insulins was associated with better clinical outcomes when compared with human insulin.

PLAIN-LANGUAGE SUMMARY

People with diabetes who are receiving dialysis for kidney failure are at high risk of cardiovascular disease and death. This study uses information from 1,446 people with kidney failure from 7 European countries who are receiving dialysis, have type 2 diabetes, and are prescribed either insulin identical to that made in the body (human insulin) or insulins with engineered extra features (insulin analog). After 3 years, fewer participants receiving analog insulins had died, had been admitted to the hospital, or had a cardiovascular event (heart attack, stroke, heart failure, or peripheral vascular disease). These findings suggest that analog insulins should be further explored as a treatment leading to better outcomes for people with diabetes on dialysis.

Challenges of Glycemic Control in People With Diabetes and Advanced Kidney Disease and the Potential of Automated Insulin Delivery

Diabetes is the leading cause of chronic kidney disease (CKD) and end-stage kidney disease in the world. It is known that maintaining optimal glycemic control can slow the progression of CKD. However, the failing kidney impacts glucose and insulin metabolism and contributes to increased glucose variability. Conventional methods of insulin delivery are not well equipped to adapt to this increased glycemic lability. Automated insulin delivery (AID) has been established as an effective treatment in patients with type 1 diabetes mellitus, and there is emerging evidence for their use in type 2 diabetes mellitus. However, few studies have examined their role in diabetes with concurrent advanced CKD. We discuss the potential benefits and challenges of AID use in patients with diabetes and advanced CKD, including those on dialysis.

Inferior Nutritional Status Significantly Differentiates Dialysis Patients with Type 1 and Type 2 Diabetes

Diabetes mellitus is currently the leading cause of end-stage renal disease. Assessing nutritional status is an important component of care in this group. This prospective observational study aimed to assess the nutritional status of type 1 and type 2 diabetes patients on hemodialysis or peritoneal dialysis and its relationship with hospitalizations and all-cause death. Adult patients with end-stage renal disease, treated with dialysis, and suffering from type 1 or type 2 diabetes, being treated with insulin, were included in the study. Exclusion criteria comprised other types of diabetes, the patient's refusal to participate in the study, and severe disorders impacting verbal-logical communication. The nutritional status based on the Nutritional Risk Index, the Geriatric Nutritional Risk Index, fat distribution measures, and the Charlson Comorbidity Index was estimated for 95 Caucasian dialysis patients with type 1 (n = 25) or type 2 (n = 70) diabetes. Patients with type 1 diabetes exhibited significantly inferior nutritional status and increased nutritional risk than those with type 2 diabetes. Lower values of nutritional indices significantly differentiated patients with type 1 from those with type 2 diabetes, with ≥84% sensitivity and specificity. Inferior nutritional status was related to all-cause hospitalizations, whereas higher comorbidity was associated with a greater likelihood of cardiovascular hospitalizations and all-cause death. The significant difference between patients with type 1 and type 2 diabetes being treated with dialysis indicates that these patients should not be considered as a homogeneous group, while also considering the greater age of patients with type 2 diabetes.

Glycated hemoglobin levels and risk of all-cause and cause-specific mortality in hemodialysis patients with diabetes

AIM

Adequate glycemic control is fundamental for improving clinical outcomes in hemodialysis patients with diabetes. However, the target for glycated hemoglobin (HbA1c) level and whether cause-specific mortality differs based on HbA1c levels remain unclear.

METHODS

A total of 24,243 HD patients with diabetes were enrolled from a multicenter, nationwide registry. We examined the association between HbA1c levels and the risk of all-cause and cause-specific mortality.

RESULTS

Compared to patients with HbA1c 6.5%-7.5%, patients with HbA_1c 8.5-9.5% and ≥9.5% were associated with a 1.26-fold (95% CI, 1.12-1.42) and 1.56-fold (95% CI, 1.37-1.77) risk for all-cause mortality. The risk of all-cause mortality did not increase in patients with HbA1c < 5.5%. In cause-specific mortality, the risk of cardiovascular deaths significantly increased from small increase of HbA1c levels. However, the risk of other causes of death increased only in patients with HbA1c > 9.5%. The slope of HR increase with increasing HbA1c levels was significantly faster for cardiovascular causes than for other causes.

CONCLUSIONS

There was a linear relationship between HbA1c levels and risk of all-cause mortality in hemodialysis patients, and the risk of cardiovascular death increased earlier and more rapidly, with increasing HbA1c levels, compared with other causes of death.

NAD(P)H: quinone oxidoreductase 1 attenuates oxidative stress and apoptosis by regulating Sirt1 in diabetic nephropathy

Background

Diabetic nephropathy (DN) is one of the main complications of diabetes, and oxidative stress plays an important role in its progression. NAD(P)H: quinone oxidoreductase 1 (NQO1) protects cells from oxidative stress and toxic quinone damage. In the present study, we aimed to investigate the protective effects and underlying mechanisms of NQO1 on diabetes-induced renal tubular epithelial cell oxidative stress and apoptosis.

Methods

In vivo, the kidneys of db/db mice, which are a type 2 diabetes model, were infected with adeno-associated virus to induce NQO1 overexpression. In vitro, human renal tubular epithelial cells (HK-2 cells) were transfected with NQO1 pcDNA3.1(+) and cultured in high glucose (HG). Gene and protein expression was assessed by quantitative real-time PCR, western blotting, immunofluorescence analysis, and immunohistochemical staining. Reactive oxygen species (ROS) were examined by MitoSox red and flow cytometry. TUNEL assays were used to measure apoptosis.

Result

In vivo, NQO1 overexpression reduced the urinary albumin/creatinine ratio (UACR) and blood urea nitrogen (BUN) level in db/db mice. Our results revealed that NQO1 overexpression could significantly increase the ratio of NAD+/NADH and silencing information regulator 1 (Sirt1) expression and block tubular oxidative stress and apoptosis in diabetic kidneys. In vitro, NQO1 overexpression reduced the generation of ROS, NADPH oxidase 1 (Nox1) and Nox4, the Bax/Bcl-2 ratio and the expression of Cleaved Caspase-3 and increased NAD+/NADH levels and Sirt1 expression in HK-2 cells under HG conditions. However, these effects were reversed by the Sirt1 inhibitor EX527.

Conclusions

All these data suggest that NQO1 has a protective effect against oxidative stress and apoptosis in DN, which may be mediated by the regulation of Sirt1 through increasing intracellular NAD+/NADH levels. Therefore, NQO1 may be a new therapeutic target for DN.

Novel approaches to hypoglycemia and burnt-out diabetes in chronic kidney disease

PURPOSE OF REVIEW

Diabetes mellitus is a leading cause of chronic kidney disease (CKD) that confers faster kidney disease progression, higher mortality, and various metabolic derangements including hypoglycemia.

RECENT FINDINGS

Even in the absence of diabetes mellitus, growing research demonstrates that CKD patients are at heightened risk for hypoglycemia via multiple pathways. In CKD patients transitioning to end-stage renal disease (ESRD), spontaneous resolution of hyperglycemia and frequent hypoglycemia resulting in reduction and/or cessation of glucose-lowering medications are frequently observed in a phenomenon described as 'burnt-out diabetes'. In non-CKD patients, it is well established that hypoglycemia is causally associated with mortality, with pathways including arrhythmias, sudden cardiac death, stroke, and seizures. Increasing evidence shows that, in CKD and ESRD patients with and without diabetes mellitus, hypoglycemia is associated with cardiovascular complications and mortality risk.

SUMMARY

Given the high prevalence of hypoglycemia in CKD patients and the morbidity and mortality associated with this metabolic complication, a multimodal strategy is needed to prevent dysglycemia, including individualization of glycemic targets, selection of glucose-lowering medications less likely to induce hypoglycemia, medical nutrition therapy administered by trained dietitians, and accurate and precise hypoglycemia detection methods, such as self-monitored blood glucose or continuous glucose monitoring including during dialysis treatment.

An easy-to-operate web-based calculator for predicting the progression of chronic kidney disease

BACKGROUND

This study aimed to establish and validate an easy-to-operate novel scoring system based on simple and readily available clinical indices for predicting the progression of chronic kidney disease (CKD).

METHODS

We retrospectively evaluated 1045 eligible CKD patients from a publicly available database. Factors included in the model were determined by univariate and multiple Cox proportional hazard analyses based on the training set.

RESULTS

Independent prognostic factors including etiology, hemoglobin level, creatinine level, proteinuria, and urinary protein/creatinine ratio were determined and contained in the model. The model showed good calibration and discrimination. The area under the curve (AUC) values generated to predict 1-, 2-, and 3-year progression-free survival in the training set were 0.947, 0.931, and 0.939, respectively. In the validation set, the model still revealed excellent calibration and discrimination, and the AUC values generated to predict 1-, 2-, and 3-year progression-free survival were 0.948, 0.933, and 0.915, respectively. In addition, decision curve analysis demonstrated that the model was clinically beneficial. Moreover, to visualize the prediction results, we established a web-based calculator ( https://ncutool.shinyapps.io/CKDprogression/ ).

CONCLUSION

An easy-to-operate model based on five relevant factors was developed and validated as a conventional tool to assist doctors with clinical decision-making and personalized treatment.

Glucose Homeostasis, Hypoglycemia, and the Burnt-Out Diabetes Phenomenon in Kidney Disease

Chronic kidney disease (CKD) is among the most prevalent and dire complications of diabetes mellitus in adults across the world. Diabetes substantially contributes to the burden of kidney disease, such that one third to one half of CKD in the United States and many other countries is attributable to diabetic kidney disease (DKD). As DKD progresses to end-stage renal disease (ESRD), patients are at heightened risk for atypical glycemic complications, including the development of burnt-out diabetes, manifested by hypoglycemic bouts and poor outcomes. Furthermore, even in the absence of diabetes, hypoglycemia is a frequent occurrence in CKD patients that may contribute to their high burden of cardiovascular disease and death. Extrapolation of data from clinical trials in high-cardiovascular-risk populations and observational studies in patients with non-dialysis-dependent (NDD) CKD and ESRD suggest that moderate glycemic targets defined by glycated hemoglobin levels of 6% to 8% and glucose levels of 100 to 150 mg/dL are associated with better survival in DKD patients. However, given the imprecision of glycated hemoglobin levels in kidney disease, further research is needed to determine the optimal glycemic metric and target in diabetic NDD-CKD and ESRD patients. Given their exceedingly high cardiovascular morbidity and mortality, there is a compelling need for further investigation of how to optimally manage dysglycemia in the NDD-CKD and ESRD populations.

Diabetes mellitus in chronic kidney disease: Biomarkers beyond HbA1c to estimate glycemic control and diabetes-dependent morbidity and mortality

Diabetes mellitus (DM) is the leading cause of chronic kidney disease (CKD). Optimal glycemic control contributes to improved outcomes in patients with DM, particularly for microvascular damage, but blood glucose levels are too variable to provide an accurate assessment and instead markers averaging long-term glycemic load are used. The most established glycemic biomarker of long-term glycemic control is HbA1c. Nevertheless, HbA1c has pitfalls that limit its accuracy to estimate glycemic control, including the presence of altered red blood cell survival, hemoglobin glycation and suboptimal performance of HbA1c assays. Alternative methods to evaluate glycemic control in patients with DM include glycated albumin, fructosamine, 1-5 anhydroglucitol, continuous glucose measurement, self-monitoring of blood glucose and random blood glucose concentration measurements. Accordingly, our aim was to review the advantages and pitfalls of these methods in the context of CKD.

Association of Glomerular Complement C4c Deposition With the Progression of Diabetic Kidney Disease in Patients With Type 2 Diabetes

Objectives: As accumulating data supporting the potential role of the complement system in the pathogenesis of diabetic kidney disease (DKD), the present study aimed to explore the association of glomerular complement C4c deposition with the baseline clinicopathological characteristics and the prognosis of DKD in type 2 diabetes (T2DM) patients.

Methods: A total of 79 T2DM patients with biopsy-proven DKD were enrolled. Clinicopathological features and renal outcomes were compared between groups divided by the glomerular C4c deposition patterns and median values of serum C4. Renal outcomes were defined by doubling of serum creatinine level or progression to end-stage renal disease (ESRD). A Cox proportional hazards model was employed to identify the risk factors associated with renal events.

Results: Patients with glomerular C4c deposition had worse renal insufficiency than those without C4c deposits, along with higher 24-h urinary protein, triglyceride, but lower serum albumin and higher interstitial inflammation score. Besides, serum C4 levels positively correlated with urinary protein and serum C3 levels. During 21.85 ± 16.32 months of follow-up, Kaplan-Meier curve analysis showed significantly faster deterioration of renal function for patients with positive glomerular C4c deposition as well as higher levels of serum C4. More specifically, more than 50% of the patients with glomerular C4c had co-deposition of C3c or C1q, and patients with glomerular complement complex of C4c and one or two of C3/C1q deposition had more severe proteinuria and a higher rate of DKD progression than those with negative C4c deposits. The univariate Cox regression indicated that factors of combined serum and glomerular C4, urinary protein, serum creatinine, serum C3, combined glomerular C4c and IgM and interstitial inflammation were associated with an increased risk of DKD, but only glomerular C4c intensity (HR 1.584, 95% CI [1.001, 2.508], p = 0.0497), as well as baseline age and diabetic neuropathy, were independent risk factors for renal survival by the multivariate Cox analysis.

Conclusions: Glomerular C4c deposition was associated with deteriorated renal function and outcomes in patients with T2DKD. Glomerular C4c deposition was an independent risk factor for DKD progression.

Mortality Risk in Chronic Kidney Disease Patients Transitioning to Dialysis: Impact of Opiate and Non-Opiate Use

BACKGROUND

Population-based studies show there is a high prevalence of chronic kidney disease (CKD) patients suffering from chronic pain. While opiates are frequently prescribed in non-dialysis-dependent CKD (NDD-CKD) patients, there may be toxic accumulation of metabolites, particularly among those progressing to end-stage renal disease (ESRD). We examined the association of opiate versus other analgesic use during the pre-ESRD period with post-ESRD mortality among NDD-CKD patients transitioning to dialysis.

METHODS

We examined a national cohort of US Veterans with NDD-CKD who transitioned to dialysis over 2007-14. Among patients who received ≥1 prescription(s) in the Veterans Affairs (VA) Healthcare System within 1 year of transitioning to dialysis, we examined associations of pre-ESRD analgesic status, defined as opiate, gabapentin/pregabalin, other non-opiate analgesic, versus no analgesic use, with post-ESRD mortality using multivariable Cox models.

RESULTS

Among 57,764 patients who met eligibility criteria, pre-ESRD opiate and gabapentin/pregabalin use were each associated with higher post-ESRD mortality (ref: no analgesic use), whereas non-opiate analgesic use was not associated with higher mortality in expanded case-mix analyses: HRs (95% CIs) 1.07 (1.05-1.10), 1.07 (1.01-1.13), and 1.00 (0.94-1.06), respectively. In secondary analyses, increasing frequency of opiate prescriptions exceeding 1 opiate prescription in the 1-year pre-ESRD period was associated with incrementally higher post-ESRD mortality (ref: no analgesic use).

CONCLUSIONS

In NDD-CKD patients transitioning to dialysis, pre-ESRD opiate and gabapentin/pregabalin use were associated with higher post-ESRD mortality, whereas non-opiate analgesic use was not associated with death. There was a graded association between increasing frequency of pre-ESRD opiate use and incrementally higher mortality.

Dencichine ameliorates renal injury by improving oxidative stress, apoptosis and fibrosis in diabetic rats

OBJECTIVE

To investigate protective efficacies and mechanisms of dencichine on diabetic kidney injury via in vitro and in vivo assays.

METHODS

Effects of dencichine on hydrogen peroxide (H₂O₂) induced oxidative damage in HK-2 renal cells were assessed by CCK-8 method. Forty streptozotocin (STZ)-induced diabetic rats with kidney injury were randomly divided into negative control group, three doses of dencichine (40, 80 and 160 mg/kg) groups. Blood biochemical and kidney related indexes as well adrenal morphological changes, apoptosis and autophagy related markers of diabetic rats were measured.

RESULTS

Cell viability of HK-2 cells with oxidative damage induced by H₂O₂ was significantly improved by dencichine with 160 μg/mL for 43.7% and 320 μg/mL for 52.9% compared with control. Moreover, the decreased reactive oxygen species (ROS), and increased intracellular antioxidant enzymes including GPX1, SOD2 and GSH were showed in dencichine groups. In addition, incubation of dencichine in HK-2 cells promoted the increase of p-AMPK, BCL2, LC3, decreased activation of p-mTOR, BAX and Caspase 3. Chronic treatment of dencichine improved the STZ-induced diabetic characteristics of model rats. Further histopathological examination of renal tissues revealed 12-week treatment of dencichine effectively improved the morphology of nephropathy in diabetic rats. Moreover, dencichine also ameliorated excessive oxidation stress, down-regulated renal cell apoptosis and fibrosis related proteins, thereby protected renal tissues in diabetic rats.

CONCLUSION

Dencichine ameliorated STZ-induced kidney injury mainly through inhibiting oxidative stress, reducing renal fibrosis, increasing autophagy, and reducing the renal cell apoptosis related proteins to protect nephrocytes and decrease renal tissue damage.

Evidence-based treatment of hyperglycaemia with incretin therapies in patients with type 2 diabetes and advanced chronic kidney disease

Type 2 diabetes is the leading cause of chronic kidney disease (CKD). The prevalence of CKD is growing in parallel with the rising number of patients with type 2 diabetes globally. At present, the optimal approach to glycaemic control in patients with type 2 diabetes and advanced CKD (categories 4 and 5) remains uncertain, as these patients were largely excluded from clinical trials of glucose-lowering therapies. Nonetheless, clinical trial data are available for the use of incretin therapies, dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists, for patients with type 2 diabetes and advanced CKD. This review discusses the role of incretin therapies in the management of these patients. Because the presence of advanced CKD in patients with type 2 diabetes is associated with a markedly elevated risk of cardiovascular disease (CVD), treatment strategies must include the reduction of both CKD and CVD risks because death, particularly from cardiovascular causes, is more probable than progression to end-stage kidney disease. The management of hyperglycaemia is essential for good diabetes care even in advanced CKD. Current evidence supports an individualized approach to glycaemic management in patients with type 2 diabetes and advanced CKD, taking account of the needs of each patient, including the presence of co-morbidities and concomitant therapies. Although additional studies are needed to establish optimal strategies for glycaemic control in patients with type 2 diabetes and advanced CKD, treatment regimens with currently available pharmacotherapy can be individually tailored to meet the needs of this growing patient population.

Race and Mortality in CKD and Dialysis: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVES

Few studies have investigated racial disparities in survival among dialysis patients in a manner that considers risk factors and mortality during the phase of kidney disease before maintenance dialysis. Our objective was to explore racial variations in survival among dialysis patients and relate them to racial differences in comorbid conditions and rates of death in the setting of kidney disease not yet requiring dialysis therapy.

STUDY DESIGN

Retrospective cohort study.

SETTINGS & PARTICIPANTS

3,288 black and white participants in the Chronic Renal Insufficiency Cohort (CRIC), none of whom were receiving dialysis at enrollment.

EXPOSURE

Race.

OUTCOME

Mortality.

ANALYTIC APPROACH

Cox proportional hazards regression was used to examine the association between race and mortality starting at: (1) time of dialysis initiation and (2) entry into the CRIC.

RESULTS

During 7.1 years of median follow-up, 678 CRIC participants started dialysis. Starting from the time of dialysis initiation, blacks had lower risk for death (unadjusted HR, 0.67; 95% CI, 0.51-0.87) compared with whites. Starting from baseline CRIC enrollment, the strength of the association between some risk factors and dialysis was notably stronger for whites than blacks. For example, the HR for dialysis onset in the presence (vs absence) of heart failure at CRIC enrollment was 1.30 (95% CI, 1.01-1.68) for blacks versus 2.78 (95% CI, 1.90-4.50) for whites, suggesting differential severity of these risk factors by race. When we included deaths occurring both before and after dialysis, risk for death was higher among blacks (vs whites) starting from CRIC enrollment (HR, 1.41; 95% CI, 1.22-1.64), but this finding was attenuated in adjusted models (HR, 1.08; 95% CI, 0.91-1.28).

LIMITATIONS

Residual confounding.

CONCLUSIONS

The apparent survival advantage among blacks over whites treated with dialysis may be attributed to selected transition of a subset of whites with more severe comorbid conditions onto dialysis.

Association of Continuation of Statin Therapy Initiated Before Transition to Chronic Dialysis Therapy With Mortality After Dialysis Initiation

IMPORTANCE

De novo statin therapy in patients receiving chronic dialysis has failed to demonstrate cardiovascular (CV) protection in randomized clinical trials and thus is not recommended by current guidelines. However, current guidelines recommend the continuation of statin therapy if initiated before transition to dialysis.

OBJECTIVE

To investigate whether the continuation of statins from advanced chronic kidney disease into the dialysis therapy period is associated with improved survival.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of US veterans transitioning to dialysis between October 1, 2007, and March 30, 2014. Participants were 14 298 US veterans who were receiving statins during the 12-month period before transition to dialysis and survived the first year of dialysis. Data analysis was conducted between August 2, 2017, and June 28, 2018.

EXPOSURES

Patients were characterized as statin continuers (n = 11 936) if statin therapy was continued for at least 6 months during the first year after dialysis initiation and as statin discontinuers (n = 2362) if therapy with statins was stopped or no statin therapy was received in the year posttransition.

MAIN OUTCOMES AND MEASURES

Associations of statin continuation with 12-month all-cause mortality and CV mortality after 1 year of dialysis initiation were examined using Cox proportional hazards regression models adjusted for demographics and comorbidities.

RESULTS

The mean (SD) age of the cohort was 71 (10) years; the cohort was 96.7% (n = 13 828) male and 21.3% (n = 3043) African American, and 74.6% (n = 10 627) had diabetes. The 12-month all-cause mortality and CV mortality rates after 1 year of transition to dialysis were lower in statin continuers: deaths per 100 person-years were 21.9 (95% CI, 20.9-22.8) and 8.1 (95% CI, 7.5-8.6) in statin continuers vs 30.3 (95% CI, 27.8-32.8) and 9.8 (95% CI, 8.3-11.2) in statin discontinuers. Moreover, lower all-cause mortality and CV mortality risks with statin continuation persisted in adjusted analyses, with hazard ratios of 0.72 (95% CI, 0.66-0.79) and 0.82 (95% CI, 0.69-0.96), respectively. Associations were similar across subgroups, including age, race, and diabetes status.

CONCLUSIONS AND RELEVANCE

In this study, the continuation of statin therapy after transition to dialysis was associated with reduced all-cause mortality and CV mortality. The study findings suggest that future studies are needed to examine potential CV benefits of continuing statin therapy after dialysis initiation.