Glycemic control and the risk of death in 1,484 patients receiving maintenance hemodialysis

Prevalence of cognitive impairment and its predictors among chronic kidney disease patients: A systematic review and meta-analysis

BACKGROUND

Cognitive impairment (CI) is common among patients with chronic kidney disease (CKD), and is associated with a poor prognosis. We assessed the prevalence and associated factors of CI in patients with CKD.

METHODS

A systematic review and meta-analysis were conducted by searching PubMed, Embase, and the Web of Science through December 1, 2023. Random effects models were performed with subgroup analyses to further explore the heterogeneity.

RESULTS

50 studies involving 25,289 CKD patients were included. The overall prevalence of CI was 40% (95% confidence interval 33-46). The pooled prevalence of CI was relatively higher in CKD patients from Africa (58%), Asia (44%) and America (37%). Attention and executive dysfunction appeared to be the most common manifestations. The prevalence of CI was higher among patients with hemodialysis (53%) and peritoneal dialysis (39%) than those without dialysis (32%) and post-kidney transplanted (26%). In addition, advanced age, the presence of diabetes and hypertension might increase the risk of CI in CKD patients.

CONCLUSIONS

People with CKD have a high prevalence of CI, especially in patients with hemodialysis. An early and comprehensive screening for CI in CKD patients is needed to improve clinical outcomes.

TRIAL REGISTRATION

Registration number: PROSPERO (CRD42023412864).

Glycemic Control and Adverse Clinical Outcomes in Patients with Chronic Kidney Disease and Type 2 Diabetes Mellitus: Results from KNOW-CKD

BACKGRUOUND

The optimal level of glycosylated hemoglobin (HbA1c) to prevent adverse clinical outcomes is unknown in patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM).

METHODS

We analyzed 707 patients with CKD G1-G5 without kidney replacement therapy and T2DM from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD), a nationwide prospective cohort study. The main predictor was time-varying HbA1c level at each visit. The primary outcome was a composite of development of major adverse cardiovascular events (MACEs) or all-cause mortality. Secondary outcomes included the individual endpoint of MACEs, all-cause mortality, and CKD progression. CKD progression was defined as a ≥50% decline in the estimated glomerular filtration rate from baseline or the onset of end-stage kidney disease.

RESULTS

During a median follow-up of 4.8 years, the primary outcome occurred in 129 (18.2%) patients. In time-varying Cox model, the adjusted hazard ratios (aHRs) for the primary outcome were 1.59 (95% confidence interval [CI], 1.01 to 2.49) and 1.99 (95% CI, 1.24 to 3.19) for HbA1c levels of 7.0%-7.9% and ≥8.0%, respectively, compared with <7.0%. Additional analysis of baseline HbA1c levels yielded a similar graded association. In secondary outcome analyses, the aHRs for the corresponding HbA1c categories were 2.17 (95% CI, 1.20 to 3.95) and 2.26 (95% CI, 1.17 to 4.37) for MACE, and 1.36 (95% CI, 0.68 to 2.72) and 2.08 (95% CI, 1.06 to 4.05) for all-cause mortality. However, the risk of CKD progression did not differ between the three groups.

CONCLUSION

This study showed that higher HbA1c levels were associated with an increased risk of MACE and mortality in patients with CKD and T2DM.

Making sense of glucose sensors in end-stage kidney disease: A review

Diabetes mellitus remains the leading cause of end-stage kidney disease worldwide. Inadequate glucose monitoring has been identified as one of the gaps in care for hemodialysis patients with diabetes, and lack of reliable methods to assess glycemia has contributed to uncertainty regarding the benefit of glycemic control in these individuals. Hemoglobin A1c, the standard metric to evaluate glycemic control, is inaccurate in patients with kidney failure, and does not capture the full range of glucose values for patients with diabetes. Recent advances in continuous glucose monitoring have established this technology as the new gold standard for glucose management in diabetes. Glucose fluctuations are uniquely challenging in patients dependent on intermittent hemodialysis, and lead to clinically significant glycemic variability. This review evaluates continuous glucose monitoring technology, its validity in the setting of kidney failure, and interpretation of glucose monitoring results for the nephrologist. Continuous glucose monitoring targets for patients on dialysis have yet to be established. While continuous glucose monitoring provides a more complete picture of the glycemic profile than hemoglobin A1c and can mitigate high-risk hypoglycemia and hyperglycemia in the context of the hemodialysis procedure itself, whether the technology can improve clinical outcomes merits further investigation.

The association between long-term glycemic control and all-cause mortality is different among older versus younger patients with diabetes mellitus and maintenance hemodialysis treatment

AIMS

Knowledge about association between glycated hemoglobin (HbA1c) and risk of all-cause mortality in patients with diabetes mellitus on maintenance hemodialysis (HD)-treatment is sparse. The study aims to investigate association between HbA1c and all-cause mortality in patients with diabetes and maintenance HD-treatment, separately for two age groups- above and below 75 years.

METHODS

2487 patients (mean age 66 years, 66 % men) were separated in two age groups: ≤75 years (n = 1810) and > 75 years (n = 677) and followed up between 2008 and 2018. Hazard ratios (HR) and 95 % confidence intervals (CI) for associations between HbA1c and all-cause mortality were calculated using Cox-regression-models.

RESULTS

1295 (52 %) patients died and 473 (70 %) among the patients above 75 years old. In the multivariate analysis, HbA1c5-6 % was used as reference. In patients ≤ 75 years old, only increased HbA1c > 9.7 %, HR2.03(CI1.43-2.89) was associated with increased risk of all-cause mortality. In patients > 75 years, HbA1c ≤ 5 %, HR1.67(CI1.16-2.40); HbA1c6.9-7.8 %, HR1.41(CI1.03-1.93) and HbA1c8.7-9.7 %, HR1.79 (CI1.08-2.96) were associated with increased risk of all-cause mortality.

CONCLUSIONS

We found a J-shaped association between HbA1c and mortality only in diabetic HD-patients > 75 years. This probably indicates that in an old population of diabetic HD-patients, both intensive glucose control and hyperglycemia could be harmful and associated with higher risk of death.

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.

Predictors of Health Deterioration Among Older New Zealanders Undergoing Dialysis: A Three-Year Accelerated Longitudinal Cohort Study

Background:

Patient involvement in dialysis decision-making is crucial, yet little is known about patient-reported outcomes over time on dialysis.

Objective:

To examine health-related outcomes over 24 and 36 months in an older cohort of dialysis patients.

Design:

The “Dialysis outcomes in those aged ≥65 years study” is a prospective longitudinal cohort study of New Zealanders with kidney failure.

Setting:

Three New Zealand nephrology units.

Patients:

Kidney failure (dialysis and predialysis) patients aged 65 or above. We have previously described outcomes after 12 months of dialysis therapy relative to baseline.

Measurements:

Patient-reported social and health factors using the SF-36, EQ-5D, and Kidney Symptom Score questionnaires.

Methods:

This article describes and compares characteristics of 120 older kidney failure patients according to whether they report “Same/better” or “Worse” health 24 and 36 months later, and identifies predictors of “worse health.” Modified Poisson regression modeling estimated relative risks (RR) of worse health.

Results:

Of 120 patients at 12 months, 47.5% had worse health or had died by 24 months. Of those surviving at 24 months (n = 80), 40% had “Worse health” or had died at 36 months. Variables independently associated with reduced risk of “Worse health” (24 months) were as follows: Māori ethnicity (RR = 0.44; 95% CI = 0.26-0.75), Pacific ethnicity (RR = 0.39; 95% CI = 0.33-0.46); greater social satisfaction (RR = 0.57; 95% CI = 0.46-0.7). Variables associated with an increased risk of “Worse health” were as follows: problems with usual activities (RR = 1.32; 95% CI = 1.04-1.37); pain or discomfort (RR = 1.48; 95% CI = 1.34, 1.63). At 36 months, lack of sense of community (RR = 1.41; 95% CI = 1.18-1.69), 2 or more comorbidities (RR = 1.21; 95% CI = 1.13-1.29), and problems with poor health (RR = 1.47; 95% CI = 1.41-1.54) were associated with “Worse health.”

Limitations:

Participant numbers restricted the number of variables able to be included in the multivariable model, and hence there may have been insufficient power to detect certain associations.

Conclusions:

In this study, the majority of older dialyzing patients report “Same/better health” at 24 and 36 months. Māori and Pacific people report better outcomes on dialysis. Social and/or clinical interventions aimed at improving social satisfaction, sense of community, and help with usual activities may impact favorably on the experiences for older dialysis patients.

Trial registration:

Australian and New Zealand clinical trials registry: ACTRN12611000024943.

Management of diabetes mellitus in dialysis patients: Obstacles and challenges

BACKGROUND AND AIMS

Diabetic kidney disease (DKD) is a major health issue that is associated with an increased risk of morbidity and mortality. The treatment of DKD is challenging given changes in blood glucose homeostasis, unclear accuracy of glucose metrics, and altered kinetics of the blood glucose-lowering medications. There is uncertainty surrounding the optimal glycemic target in this population although recent epidemiologic data suggest that HbA1c ranges of 6-8%, as well as 7-9%, are associated with increased survival rates among diabetic dialysis patients. Furthermore, the treatment of diabetes in patients maintained on dialysis is challenging, and many blood glucose-lowering medications are renally metabolized and excreted hence requiring dose adjustment or avoidance in dialysis patients.

METHOD

ology: PubMed, Google Scholar, and Medline were searched for all literature discussing the management of diabetes in dialysis patients.

RESULTS

The literature was discussed under many subheadings providing the latest evidence in the treatment of diabetes in dialysis patients.

CONCLUSION

The management of diabetes in dialysis is very complex requiring a multi-disciplinary team involving endocrinologists and nephrologists to achieve targets and reduce morbidity and mortality.

Glycemic Control and Infections Among US Hemodialysis Patients With Diabetes Mellitus

Introduction

Patients with diabetes mellitus (DM) on hemodialysis (HD) may be particularly vulnerable to infections.

Methods

We used merged data from the United States Renal Data System and electronic health records data from a large US dialysis provider to retrospectively examine the association between glycemic control and infections in these patients. Adult patients with DM aged ≥18 years who initiated in-center maintenance HD treatment from 2006 to 2011 and survived >90 days were included. Quarterly mean time-averaged hemoglobin A1c (HbA1c) values were categorized into <5.5%, 5.5 to <6.5%, 6.5 to <7.5%, 7.5 to <8.5%, and ≥8.5%. We used Medicare claims to ascertain infection-related outcomes and the ESRD Death Notification to identify death from infectious cause. We used Cox proportional hazards models to estimate multivariable-adjusted hazard ratios and 95% confidence intervals (CIs) for the associations between time-averaged HbA1c categories and infectious events.

Results

In a cohort of 33,753 eligible patients, those with higher HbA1c levels had higher rates of diabetic foot infections and skin and soft tissue infections, with patients with HbA1c ≥8.5% having 23% (95% CI, 5%, 45%) and 22% (95% CI, 5%, 42%) higher rates, respectively, compared with HbA1c 5.5 to <6.5%. Patients in the lower HbA1c categories had higher rates of infection-related and all-cause mortality (P-for-trend <0.001).

Conclusion

This study highlights the need for greater attention to foot evaluation and skin and soft tissue infections among patients on HD with less than optimal diabetes control.

Cognitive Impairment in CKD: Pathophysiology, Management, and Prevention

Patients with chronic kidney disease (CKD) are at substantially higher risk for developing cognitive impairment compared with the general population, and both lower glomerular filtration rate and the presence of albuminuria are associated with the development of cognitive impairment and poorer cognitive function. Given the excess of vascular disease seen in individuals with CKD, cerebrovascular disease is likely the predominant pathology underlying these associations, though impaired clearance of uremic metabolites, depression, sleep disturbance, anemia, and polypharmacy may also contribute. Modification of vascular disease risk factors may be helpful in limiting decline, though definite data are lacking. Specific to CKD, targeting a low blood pressure and reduction in albuminuria with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may slow cognitive decline, albeit modestly. Initiation of dialysis can improve severe impairment associated with uremia but does not appear to affect more subtle chronic cognitive impairment. In contrast, kidney transplantation appears to lead to improved cognitive function in many transplant recipients, suggesting that dialysis methods do not provide the same cognitive benefits as having a functioning kidney. Management of patients with both CKD and cognitive impairment should include a comprehensive plan including more frequent follow-up visits; involvement of family in shared decision making; measures to improve compliance, such as written instruction and pill counts; and a focus on advance directives in conjunction with an emphasis on understanding an individual patient's life goals. Further research is needed on novel therapies, including innovative dialysis methods, that aim to limit the development of cognitive impairment, slow decline in those with prevalent impairment, and improve cognitive function.

Risk Factors Before Dialysis Predominate as Mortality Predictors in Diabetic Maintenance Dialysis patients

Diabetic patients undergoing maintenance dialysis (MD) have a particularly high mortality rate. Many of the risk factors for mortality have been identified in diabetics who die before reaching end stage renal disease (ESRD), i.e. before dialysis (BD). In addition, many risk factors for mortality have been identified in diabetics after dialysis onset (AD). However, whether in the BD period there are long-term risk factors for AD mortality in diabetics is unknown. We therefore investigated a new concept, i.e. that clinical and biochemical risk factors during the BD stage affect long-term AD mortality. We performed a population based retrospective cohort study, in diabetic CKD patients in a single center in south Israel who initiated MD between the years 2003 and 2015. Clinical and biochemical data 12 months BD and 6 months AD were collected and evaluated for association with mortality AD using Cox’s proportional-hazards model. BD parameters that were found to be significant were adjusted for significant parameters AD, thus generating a “combined” regression model in order to isolate the contribution of BD factors on long term mortality. Six hundred and fifty two diabetic MD patients were included in the final analysis. Four independent BD parameters were found in the multivariate model to significantly predict AD mortality: age, BMI (inversely), pulse pressure (U-shaped) and cardiovascular comorbidity. AD independent risk factors for mortality were age, BMI (inversely) and albumin (inversely). Of note, BD factors remained dominantly significant even after additionally adjusting for AD factors. No association was found between either BD HbA1C levels or BD proteinuria and AD mortality. In diabetics who reach ESRD, BD parameters can predict long term AD mortality. Thus, some of the factors affecting the poor survival of diabetic MD patients appear to begin already in the BD period.

Insulin and glucose-lowering agents for treating people with diabetes and chronic kidney disease

BACKGROUND

Diabetes is the commonest cause of chronic kidney disease (CKD). Both conditions commonly co-exist. Glucometabolic changes and concurrent dialysis in diabetes and CKD make glucose-lowering challenging, increasing the risk of hypoglycaemia. Glucose-lowering agents have been mainly studied in people with near-normal kidney function. It is important to characterise existing knowledge of glucose-lowering agents in CKD to guide treatment.

OBJECTIVES

To examine the efficacy and safety of insulin and other pharmacological interventions for lowering glucose levels in people with diabetes and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs looking at head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in people with diabetes and CKD (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2) were eligible.

DATA COLLECTION AND ANALYSIS

Four authors independently assessed study eligibility, risk of bias, and quality of data and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Forty-four studies (128 records, 13,036 participants) were included. Nine studies compared sodium glucose co-transporter-2 (SGLT2) inhibitors to placebo; 13 studies compared dipeptidyl peptidase-4 (DPP-4) inhibitors to placebo; 2 studies compared glucagon-like peptide-1 (GLP-1) agonists to placebo; 8 studies compared glitazones to no glitazone treatment; 1 study compared glinide to no glinide treatment; and 4 studies compared different types, doses or modes of administration of insulin. In addition, 2 studies compared sitagliptin to glipizide; and 1 study compared each of sitagliptin to insulin, glitazars to pioglitazone, vildagliptin to sitagliptin, linagliptin to voglibose, and albiglutide to sitagliptin. Most studies had a high risk of bias due to funding and attrition bias, and an unclear risk of detection bias.Compared to placebo, SGLT2 inhibitors probably reduce HbA1c (7 studies, 1092 participants: MD -0.29%, -0.38 to -0.19 (-3.2 mmol/mol, -4.2 to -2.2); I2 = 0%), fasting blood glucose (FBG) (5 studies, 855 participants: MD -0.48 mmol/L, -0.78 to -0.19; I2 = 0%), systolic blood pressure (BP) (7 studies, 1198 participants: MD -4.68 mmHg, -6.69 to -2.68; I2 = 40%), diastolic BP (6 studies, 1142 participants: MD -1.72 mmHg, -2.77 to -0.66; I2 = 0%), heart failure (3 studies, 2519 participants: RR 0.59, 0.41 to 0.87; I2 = 0%), and hyperkalaemia (4 studies, 2788 participants: RR 0.58, 0.42 to 0.81; I2 = 0%); but probably increase genital infections (7 studies, 3086 participants: RR 2.50, 1.52 to 4.11; I2 = 0%), and creatinine (4 studies, 848 participants: MD 3.82 μmol/L, 1.45 to 6.19; I2 = 16%) (all effects of moderate certainty evidence). SGLT2 inhibitors may reduce weight (5 studies, 1029 participants: MD -1.41 kg, -1.8 to -1.02; I2 = 28%) and albuminuria (MD -8.14 mg/mmol creatinine, -14.51 to -1.77; I2 = 11%; low certainty evidence). SGLT2 inhibitors may have little or no effect on the risk of cardiovascular death, hypoglycaemia, acute kidney injury (AKI), and urinary tract infection (low certainty evidence). It is uncertain whether SGLT2 inhibitors have any effect on death, end-stage kidney disease (ESKD), hypovolaemia, fractures, diabetic ketoacidosis, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, DPP-4 inhibitors may reduce HbA1c (7 studies, 867 participants: MD -0.62%, -0.85 to -0.39 (-6.8 mmol/mol, -9.3 to -4.3); I2 = 59%) but may have little or no effect on FBG (low certainty evidence). DPP-4 inhibitors probably have little or no effect on cardiovascular death (2 studies, 5897 participants: RR 0.93, 0.77 to 1.11; I2 = 0%) and weight (2 studies, 210 participants: MD 0.16 kg, -0.58 to 0.90; I2 = 29%; moderate certainty evidence). Compared to placebo, DPP-4 inhibitors may have little or no effect on heart failure, upper respiratory tract infections, and liver impairment (low certainty evidence). Compared to placebo, it is uncertain whether DPP-4 inhibitors have any effect on eGFR, hypoglycaemia, pancreatitis, pancreatic cancer, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, GLP-1 agonists probably reduce HbA1c (7 studies, 867 participants: MD -0.53%, -1.01 to -0.06 (-5.8 mmol/mol, -11.0 to -0.7); I2 = 41%; moderate certainty evidence) and may reduce weight (low certainty evidence). GLP-1 agonists may have little or no effect on eGFR, hypoglycaemia, or discontinuation due to adverse effects (low certainty evidence). It is uncertain whether GLP-1 agonists reduce FBG, increase gastrointestinal symptoms, or affect the risk of pancreatitis (very low certainty evidence).Compared to placebo, it is uncertain whether glitazones have any effect on HbA1c, FBG, death, weight, and risk of hypoglycaemia (very low certainty evidence).Compared to glipizide, sitagliptin probably reduces hypoglycaemia (2 studies, 551 participants: RR 0.40, 0.23 to 0.69; I2 = 0%; moderate certainty evidence). Compared to glipizide, sitagliptin may have had little or no effect on HbA1c, FBG, weight, and eGFR (low certainty evidence). Compared to glipizide, it is uncertain if sitagliptin has any effect on death or discontinuation due to adverse effects (very low certainty).For types, dosages or modes of administration of insulin and other head-to-head comparisons only individual studies were available so no conclusions could be made.

AUTHORS' CONCLUSIONS

Evidence concerning the efficacy and safety of glucose-lowering agents in diabetes and CKD is limited. SGLT2 inhibitors and GLP-1 agonists are probably efficacious for glucose-lowering and DPP-4 inhibitors may be efficacious for glucose-lowering. Additionally, SGLT2 inhibitors probably reduce BP, heart failure, and hyperkalaemia but increase genital infections, and slightly increase creatinine. The safety profile for GLP-1 agonists is uncertain. No further conclusions could be made for the other classes of glucose-lowering agents including insulin. More high quality studies are required to help guide therapeutic choice for glucose-lowering in diabetes and CKD.

Usefulness of glycated albumin as a biomarker for glucose control and prognostic factor in chronic kidney disease patients on dialysis (CKD-G5D)

In chronic kidney disease patients on dialysis (CKD-G5D) accurate assessment of glycemic control is vital to improve their outcome and survival. The best glycemic marker for glucose control in these patients is still debated because several clinical and pharmacological factors may affect the ability of the available biomarkers to reflect the patient's glycemic status properly. This review discusses the role of glycated albumin (GA) both as a biomarker for glucose control and as a prognostic factor in CKD-G5D; it also looks at the pros and cons of GA in comparison to the other markers and its usefulness in hemodialysis and peritoneal dialysis.

Is the management of diabetes different in dialysis patients?

Diabetes is highly and increasingly prevalent in the dialysis population and negatively impacts both quality and quantity of life. Nevertheless, the best approach to these patients is still debatable. The question of whether the management of diabetes should be different in dialysis patients does not have a clear yes or no answer but is divided into too many sub-issues that should be carefully considered. In this review, lifestyle, cardiovascular risk, and hyperglycemia management are explored, emphasizing the possible pros and cons of a similar approach to diabetes in dialysis patients compared to the general population.

Vascular calcification: When should we interfere in chronic kidney disease patients and how?

Chronic kidney disease (CKD) patients are endangered with the highest mortality rate compared to other chronic diseases. Cardiovascular events account for up to 60% of the fatalities. Cardiovascular calcifications affect most of the CKD patients. Most of this calcification is related to disturbed renal phosphate handling. Fibroblast growth factor 23 and klotho deficiency were incriminated in the pathogenesis of vascular calcification through different mechanisms including their effects on endothelium and arterial wall smooth muscle cells. In addition, deficient klotho gene expression, a constant feature of CKD, promotes vascular pathology and shares in progression of the CKD. The role of gut in the etio-pathogenesis of systemic inflammation and vascular calcification is a newly discovered mechanism. This review will cover the medical history, prevalence, pathogenesis, clinical relevance, different tools used to diagnose, the ideal timing to prevent or to withhold the progression of vascular calcification and the different medications and medical procedures that can help to prolong the survival of CKD patients.

Diabetes mellitus and renal failure: Prevention and management

Nowadays, diabetes mellitus (DM) and hypertension are considered as the most common causes of end-stage renal disease (ESRD). In this paper, other than presenting the role of DM in ESRD, glucose metabolism and the management of hyperglycemia in these patients are reviewed. Although in several large studies there was no significant relationship found between tight glycemic control and the survival of ESRD patients, it is recommended that glycemic control be considered as the main therapeutic goal in the treatment of these patients to prevent damage to other organs. Glycemic control is perfect when fasting blood sugar is less than 140 mg/dL, 1-h postprandial blood glucose is less than 200 mg/dL, and glycosylated hemoglobin (HbA1c) is 6-7 in patients with type 1 diabetes and 7-8 in patients with type 2 diabetes. Administration of metformin should be avoided in chronic renal failure (CRF) because of lactic acidosis, the potentially fatal complication of metformin, but glipizide and repaglinide seem to be good choices.

What is the Role of HbA1c in Diabetic Hemodialysis Patients?

The definition of a good glycemic control in patients with diabetes mellitus on hemodialysis is far from settled. In the general population, hemoglobin A1c is highly correlated with the average glycemia of the last 8-12 weeks. However, in hemodialysis patients, the correlation of hbA1c with glycemia is weaker as it also reflects changes in hemoglobin characteristics and red blood cells half-life. As expected, studies show that the association between HbA1c and outcomes in these patients differ from the general population. Therefore, the value of HbA1c in the treatment of hemodialysis patients has been questioned. Guidelines are generally cautious in their recommendations about possible targets of HbA1c in this population. Indeed, the risk of not treating hyperglycemia should be weighed against the particularly high risk of precipitating hypoglycemia in dialysis patients. In this review, a critical analysis of the current role of HbA1c in the care of hemodialysis patients is presented.

High blood glucose independent of pre-existing diabetic status predicts mortality in patients initiating peritoneal dialysis therapy

PURPOSE

Poor glycemic control associates with increased mortality in diabetic (DM) dialysis patients, but it is less well established whether high blood glucose (BG) independent of pre-existing diabetic status associates with mortality in dialysis patients. We assessed factors affecting BG at the start of peritoneal dialysis (PD) and its mortality-predictive impact in Korean PD patients.

METHODS

In 174 PD patients (55 % males, 56 % DM), BG, nutritional status, comorbidity (CMD), and residual renal function (RRF) were assessed in conjunction with dialysis initiation. Determinants of BG and its association with mortality after a mean follow-up period of 30 ± 24 months were analyzed.

RESULTS

On Cox proportional hazards analysis comprising all patients, old age, high CMD score, presence of protein energy wasting, and low serum albumin (Salb) concentration were independent predictors of mortality but not a high-BG level, while in patients without pre-existing diabetic status, high BG, together with old age and high CMD score, was an independent predictor of mortality. After adjustment for age, CMD score, and Salb, the risk ratio for mortality increased by 12 % per 1 mg/dL increase in BG in the non-DM patients. Patient survival in patients without pre-existing diabetic status with high BG did not differ from DM patients, but the survival of patients with high BG was significantly lower than in patients with low BG. In patients without pre-existing diabetic status, in multiple regression analysis, high BG at initiation of PD associated with high age, high body mass index, and low RRF.

CONCLUSIONS

High blood glucose at initiation of PD associated with an increased mortality risk in PD patients without pre-existing diabetic status suggesting that blood glucose monitoring and surveillance of factors contributing to poor glycemic control are warranted in patients initiating PD therapy.

Glucose Serum Concentrations and Cardiovascular Disease in Patients on the End Stage of Renal Disease without Diabetes Mellitus

Background/Aim: It is still controversial whether tighter glycemic control is associated with better clinical outcomes in patients with kidney failure. We examined the association between glucose serum concentrations and cardiovascular disease in patients on the end stage of renal disease without diabetes mellitus. Methods: We studied 76 patients on on-line hemodiafiltration. Cardiovascular disease was defined by the existence of coronary disease (CD). Arterial stiffness was measured as carotid-femoral pulse wave velocity (c-fPWV) and carotid augmentation index (AIx). The concentrations of beta2-microglobulin (β2M) and insulin were measured by radioimmunoassays and insulin resistance by HOMA-IR. We built a logistic-regression analysis to examine the role of glucose on cardiovascular disease after adjustment for the traditional and specific risk factors for dialysis patients. Results: Serum glucose was positively correlated with beta2M, insulin and HOMA-IR (r = 0.361, p = 0.002, r = 0.581, p = 0.001 and r = 0.753, p = 0.001 respectively). Logistic-regression analysis did not show significant impact of glucose concentrations on cardiovascular disease after adjustment for traditional and specific risk factors. Conclusions: The association between elevated glucose serum concentrations and represented by coronary syndrome cardiovascular disease in patients on the end stage of renal disease without diabetes mellitus was not found significant.

The Benefit of a Glucose-Sparing PD Therapy on Glycemic Control Measured by Serum Fructosamine in Diabetic Patients in a Randomized, Controlled Trial (IMPENDIA)

BACKGROUND/AIMS

Poor glycemic control can lead to increased morbidity and mortality in peritoneal dialysis (PD) patients. Serum fructosamine may be a more reliable marker of glycemic control than HbA1c in dialysis patients.

METHODS

We evaluated the effects of a glucose-sparing PD regimen on serum fructosamine. In the multicenter, controlled IMPENDIA trial, eligible diabetic PD patients were randomized (1:1) to a 24-hour combination of a glucose sparing regimen (n = 89) or a glucose-based therapy (n = 91). Serum fructosamine and HbA1c were measured at baseline, 3 months and 6 months; fructosamine measurements were corrected for serum albumin (AlbF).

RESULTS

Serum fructosamine decreased from 297 to 253 µmol/l in the glucose-sparing group (95% confidence interval [CI] for the difference, -26 to -68, p < 0.001), and increased from 311 to 314 µmol/l in the glucose-only group (95% CI for the difference, -23 to +19, p = 0.87). The mean difference in change of fructosamine levels between groups at 6 months was 64 µmol/l (95% CI 29-99, p < 0.001). HbA1c decreased versus baseline in both groups (treatment difference 0.3%, p = 0.07). The correlation between AlbF and baseline fasting serum glucose was stronger than that seen between HbA1c and baseline fasting serum glucose (r = 0.47, p < 0.0001 and r = 0.31, p < 0.0001, respectively).

CONCLUSION

A glucose-sparing regimen (P-E-N) improved glycemic control as measured by serum fructosamine. Further studies are needed to establish fructosamine targets that will reduce the morbidity risk related to hyperglycemia in PD patients.

How do We Manage Coronary Artery Disease in Patients with CKD and ESRD?

Chronic kidney disease (CKD) has been shown to be an independent risk factor for cardiovascular events. In addition, patients with pre-dialysis CKD appear to be more likely to die of heart disease than of kidney disease. CKD accelerates coronary artery atherosclerosis by several mechanisms, notably hypertension and dyslipidemia, both of which are known risk factors for coronary artery disease. In addition, CKD alters calcium and phosphorus homeostasis, resulting in hypercalcemia and vascular calcification, including the coronary arteries. Mortality of patients on long-term dialysis therapy is high, with age-adjusted mortality rates of about 25% annually. Because the majority of deaths are caused by cardiovascular disease, routine cardiac catheterization of new dialysis patients was proposed as a means of improving the identification and treatment of high-risk patients. However, clinicians may be uncomfortable exposing asymptomatic patients to such invasive procedures like cardiac catheterization, thus noninvasive cardiac risk stratification was investigated widely as a more palatable alternative to routine diagnostic catheterization. The effective management of coronary artery disease is of paramount importance in uremic patients. The applicability of diagnostic, preventive, and treatment modalities developed in nonuremic populations to patients with kidney failure cannot necessarily be extrapolated from clinical studies in non-kidney failure populations. Noninvasive diagnostic testing in uremic patients is less accurate than in nonuremic populations. Initial data suggest that dobutamine echocardiography may be the preferred diagnostic method. PCI with stenting is a less favorable alternative to CABG, however, it has a faster recovery time, reduced invasiveness, and no overall mortality difference in nondiabetic and non-CKD patients compared with CABG. CABG is associated with reduced repeat revascularizations, greater relief of angina, and increased long term survival. However, CABG is associated with a higher incidence of post-operative risks. The treatment chosen for each patient should be an individualized decision based upon numerous risk factors. CKD is associated with higher rates of CAD, with 44% of all-cause mortality attributable to cardiac disease and about 20% from acute MI. Optimal treatment including aggressive lifestyle modifications and concomitant medical therapy should be implemented in all patients to maximize benefits from either PCI or CABG. Future prospective randomized controlled trials with newer second or third generation DES and bioabsorbable DES are necessary to determine if PCI may be non-inferior to CABG in the future.

The effects of comorbidity on the benefits and harms of treatment for chronic disease: a systematic review

Background

There are concerns about the potential for unintentional harms when clinical practice guidelines are applied to patients with multimorbidity. The objective was to summarize the evidence regarding the effect(s) of comorbidity on the outcomes of medication for an index chronic condition.

Methods

A systematic review was conducted of studies published in MEDLINE and Cochrane Trials before May 2012. The search strategy was constructed to identify articles indexed with “comorbidity” or a related term or by a given condition and one or more additional specified comorbid conditions. The search yielded 3252 articles, of which 37 passed the title/abstract screening process, and 22 were included after full-text review. An additional 23 articles were identified by screening the reference lists for included articles. Information was extracted on study design; population; therapy; comparison groups; outcome(s); main findings.

Findings

Indexing of articles was inconsistent, with no term for “multimorbidity,” and rare use of “comorbidity”. Only one article examined the effects of comorbidity per se, finding no benefit of tight control of DM among persons with high comorbidity, defined using a comorbidity index. The remainder examined pairs of conditions, the majority of which were post-hoc analyses of randomized controlled trials and which found no difference in outcomes according to whether a comorbid condition was present. Several demonstrated no difference or an increased risk of adverse outcome among persons with DM and tight control of HTN as compared to usual control. Several demonstrated lack of benefit of statins among persons with end-stage renal disease.

Conclusions

There is limited evidence regarding the effects of multiple comorbidities on treatment outcomes. The majority of studies demonstrated no effect of a single comorbid condition on outcomes. Additional studies examining a broad range of comorbidity are required, along with clear and consistent indexing to allow for improved synthesis of the evidence.

The Effect of Glycated Hemoglobin and Albumin-Corrected Glycated Serum Protein on Mortality in Diabetic Patients Receiving Continuous Peritoneal Dialysis

OBJECTIVE

To explore the effect of glycated hemoglobin (HbA1c) and albumin-corrected glycated serum proteins (Alb-GSP) on the mortality of diabetic patients receiving continuous peritoneal dialysis (PD).

METHODS

In this single-center retrospective cohort study, incident diabetic PD patients from January 1, 2006, to December 31, 2010, were recruited, and followed up until December 31, 2011. The effect of HbA1c and Alb-GSP on mortality was evaluated by Cox proportional hazards models.

RESULTS

A total of 200 patients (60% male, mean age 60.3 ± 10.6 years) with a mean follow-up of 29.0 months (range: 4.3 - 71.5 months) were recruited. Sixty-four patients died during the follow-up period, of whom 21 died of cardiovascular disease (CVD). Mean values for HbA1c, GSP and Alb-GSP were 6.7% (range: 4.1 - 12.5%), 202 μmol/L (range: 69 - 459 μmol/L), and 5.78 μmol/g (range: 2.16 - 14.98 μmol/g), respectively. The concentrations of GSP and Alb-GSP were closely correlated with HbA1c (r = 0.41, p < 0.001 and r = 0.45, p < 0.001, respectively). In multivariate Cox proportional hazards models, patients with HbA1c ≥ 8% were associated with increased risk of all-cause mortality (hazard ratio [HR] = 2.29, 95% confidence interval [CI]: 1.06 - 4.96, p = 0.04), but no increased mortality in patients with 6.0% ≤ HbA1c ≤ 7.9%. Patients with Alb-GSP ≤ 4.50 μmol/g had increased all-cause and non-cardiovascular mortality (HR = 2.42, 95% CI: 1.13 - 5.19, p = 0.02; and HR = 2.98, 95% CI: 1.05 - 8.48, p = 0.04 respectively).

CONCLUSIONS

Increased HbA1c and decreased Alb-GSP may be associated with poorer survival in diabetic PD patients, with a non-significant trend observed for poorer survival with the highest level of Alb-GSP.

HbA1c and survival in maintenance hemodialysis patients with diabetes in Han Chinese population

BACKGROUND

Previous observational studies using differing methodologies have yielded inconsistent results regarding the association between glycemic control and outcomes in diabetic patients receiving maintenance hemodialysis (MHD). The aim of this study was to investigate the association between HbA1c and survival in diabetic MHD patients in Han Chinese population.

METHODS

A 5-year cohort (October 2007-December 2013) of 236 diabetic MHD patients with HbA1c data was examined for associations between HbA1c and mortality. Death hazard ratios (HR) were estimated using Cox regressions.

RESULTS

Two hundred and thirty-six diabetes patients undergoing MHD in clinics over 5 years were included in our study. Unadjusted survival analyses indicated paradoxically lower death HRs with higher HbA1c values. However, after adjusting for potential confounders (demographics, dialysis vintage, comorbidity, anemia, and inflammation), higher HbA1c values were incrementally associated with higher death risks.

CONCLUSIONS

Poor glycemic control (HbA1c ≥ 8 %) appears to be associated with decreased survival in the general population of diabetic MHD patients. Our study suggests that moderate hyperglycemia increases the risk for all-cause mortality of diabetic MHD patients in Han Chinese population.

Updates on the management of diabetes in dialysis patients

Diabetes mellitus is the leading cause of end-stage renal disease (ESRD) in the U.S. and many countries globally. The role of improved glycemic control in ameliorating the exceedingly high mortality risk of diabetic dialysis patients is unclear. The treatment of diabetes in ESRD patients is challenging, given changes in glucose homeostasis, the unclear accuracy of glycemic control metrics, and the altered pharmacokinetics of glucose-lowering drugs by kidney dysfunction, the uremic milieu, and dialysis therapy. Up to one-third of diabetic dialysis patients may experience spontaneous resolution of hyperglycemia with hemoglobin A1c (HbA1c) levels <6%, a phenomenon known as "Burnt-Out Diabetes," which remains with unclear biologic plausibility and undetermined clinical implications. Conventional methods of glycemic control assessment are confounded by the laboratory abnormalities and comorbidities associated with ESRD. Similar to more recent approaches in the general population, there is concern that glucose normalization may be harmful in ESRD patients. There is uncertainty surrounding the optimal glycemic target in this population, although recent epidemiologic data suggest that HbA1c ranges of 6% to 8%, as well as 7% to 9%, are associated with increased survival rates among diabetic dialysis patients. Lastly, many glucose-lowering drugs and their active metabolites are renally metabolized and excreted, and hence, require dose adjustment or avoidance in dialysis patients.

Randomized, controlled trial of glucose-sparing peritoneal dialysis in diabetic patients

Glucose-containing peritoneal dialysis solutions may exacerbate metabolic abnormalities and increase cardiovascular risk in diabetic patients. Here, we examined whether a low-glucose regimen improves metabolic control in diabetic patients undergoing peritoneal dialysis. Eligible patients were randomly assigned in a 1:1 manner to the control group (dextrose solutions only) or to the low-glucose intervention group (IMPENDIA trial: combination of dextrose-based solution, icodextrin and amino acids; EDEN trial: a different dextrose-based solution, icodextrin and amino acids) and followed for 6 months. Combining both studies, 251 patients were allocated to control (n=127) or intervention (n=124) across 11 countries. The primary endpoint was change in glycated hemoglobin from baseline. Mean glycated hemoglobin at baseline was similar in both groups. In the intention-to-treat population, the mean glycated hemoglobin profile improved in the intervention group but remained unchanged in the control group (0.5% difference between groups; 95% confidence interval, 0.1% to 0.8%; P=0.006). Serum triglyceride, very-low-density lipoprotein, and apolipoprotein B levels also improved in the intervention group. Deaths and serious adverse events, including several related to extracellular fluid volume expansion, increased in the intervention group, however. These data suggest that a low-glucose dialysis regimen improves metabolic indices in diabetic patients receiving peritoneal dialysis but may be associated with an increased risk of extracellular fluid volume expansion. Thus, use of glucose-sparing regimens in peritoneal dialysis patients should be accompanied by close monitoring of fluid volume status.

Improved glucose tolerance after high-load strength training in patients undergoing dialysis

BACKGROUND/AIMS

The aim of this controlled study was to investigate the effect of high-load strength training on glucose tolerance in patients undergoing dialysis.

METHODS

23 patients treated by dialysis underwent a 16-week control period followed by 16 weeks of strength training three times a week. Muscle fiber size, composition and capillary density were analyzed in biopsies obtained in the vastus lateralis muscle. Glucose tolerance and the insulin response were measured by a 2-hour oral glucose tolerance test.

RESULTS

All outcome measures remained unchanged during the control period. After strength training the relative area of type 2X fibers was decreased. Muscle fiber size and capillary density remained unchanged. After the strength training, insulin concentrations were significantly lower in patients with impaired glucose tolerance or type 2 diabetes (n = 14) (fasting insulin from 68 ± 12 (46-96) to 54 ± 10 (37-77) pmol/l, p < 0.05, 2-hour insulin from 533 ± 104 (356-776) to 344 ± 68 (226-510) pmol/l, p < 0.05, total insulin area under the curve from 1,868 ± 334 (1,268-2,536) to 1,465 ± 222 (1,094-1,913), p < 0.05). Insulin concentrations were unchanged in patients with normal glucose tolerance (n = 9).

CONCLUSION

The conducted strength training was associated with a significant improvement in glucose tolerance in patients with impaired glucose tolerance or type 2 diabetes undergoing dialysis. The effect was apparently not associated with muscle hypertrophy, whereas the muscle fiber type composition was changed.

Serum fructosamine and glycated albumin and risk of mortality and clinical outcomes in hemodialysis patients

OBJECTIVE

Assays for serum total glycated proteins (fructosamine) and the more specific glycated albumin may be useful indicators of hyperglycemia in dialysis patients, either as substitutes or adjuncts to standard markers such as hemoglobin A1c, as they are not affected by erythrocyte turnover. However, their relationship with long-term outcomes in dialysis patients is not well described.

RESEARCH DESIGN AND METHODS

We measured fructosamine and glycated albumin in baseline samples from 503 incident hemodialysis participants of a national prospective cohort study, with enrollment from 1995-1998 and median follow-up of 3.5 years. Outcomes were all-cause and cardiovascular disease (CVD) mortality and morbidity (first CVD event and first sepsis hospitalization) analyzed using Cox regression adjusted for demographic and clinical characteristics, and comorbidities.

RESULTS

Mean age was 58 years, 64% were white, 54% were male, and 57% had diabetes. There were 354 deaths (159 from CVD), 302 CVD events, and 118 sepsis hospitalizations over follow-up. Both fructosamine and glycated albumin were associated with all-cause mortality; adjusted HR per doubling of the biomarker was 1.96 (95% CI 1.38-2.79) for fructosamine and 1.40 (1.09-1.80) for glycated albumin. Both markers were also associated with CVD mortality [fructosamine 2.13 (1.28-3.54); glycated albumin 1.55 (1.09-2.21)]. Higher values of both markers were associated with trends toward a higher risk of hospitalization with sepsis [fructosamine 1.75 (1.01-3.02); glycated albumin 1.39 (0.94-2.06)].

CONCLUSIONS

Serum fructosamine and glycated albumin are risk factors for mortality and morbidity in hemodialysis patients.

KDOQI Clinical Practice Guideline for Diabetes and CKD: 2012 Update

The 2012 update of the Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Diabetes and Chronic Kidney Disease (CKD) is intended to assist the practitioner caring for patients with diabetes and CKD. Substantial high-quality new evidence has emerged since the original 2007 KDOQI guideline that could significantly change recommendations for clinical practice. As such, revisions of prior guidelines are offered that specifically address hemoglobin A(1c) (HbA(1c)) targets, treatments to lower low-density lipoprotein cholesterol (LDL-C) levels, and use of angiotensin-converting enzyme inhibitor (ACE-I) and angiotensin receptor blocker (ARB) treatment in diabetic patients with and without albuminuria. Treatment approaches are addressed in each section and the stated guideline recommendations are based on systematic reviews of relevant trials. Appraisal of the quality of the evidence and the strength of recommendations followed the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Limitations of the evidence are discussed and specific suggestions are provided for future research.

Hemoglobin A(1c) levels and mortality in the diabetic hemodialysis population: findings from the Dialysis Outcomes and Practice Patterns Study (DOPPS)

OBJECTIVE

Lowering hemoglobin A(1c) to <7% reduces the risk of microvascular complications of diabetes, but the importance of maintaining this target in diabetes patients with kidney failure is unclear. We evaluated the relationship between A(1c) levels and mortality in an international prospective cohort study of hemodialysis patients.

RESEARCH DESIGN AND METHODS

Included were 9,201 hemodialysis patients from 12 countries (Dialysis Outcomes and Practice Patterns Study 3 and 4, 2006-2010) with type 1 or type 2 diabetes and at least one A(1c) measurement during the first 8 months after study entry. Associations between A(1c) and mortality were assessed with Cox regression, adjusting for potential confounders.

RESULTS

The association between A(1c) and mortality was U-shaped. Compared with an A(1c) of 7-7.9%, the hazard ratios (95% CI) for A(1c) levels were 1.35 (1.09-1.67) for <5%, 1.18 (1.01-1.37) for 5-5.9%, 1.21 (1.05-1.41) for 6-6.9%, 1.16 (0.94-1.43) for 8-8.9%, and 1.38 (1.11-1.71) for ≥9.0%, after adjustment for age, sex, race, BMI, serum albumin, years of dialysis, serum creatinine, 12 comorbid conditions, insulin use, hemoglobin, LDL cholesterol, country, and study phase. Diabetes medications were prescribed for 35% of patients with A(1c) <6% and not prescribed for 29% of those with A(1c) ≥9%.

CONCLUSIONS

A(1c) levels strongly predicted mortality in hemodialysis patients with type 1 or type 2 diabetes. Mortality increased as A(1c) moved further from 7-7.9%; thus, target A(1c) in hemodialysis patients may encompass values higher than those recommended by current guidelines. Modifying glucose-lowering medicines for dialysis patients to target A(1c) levels within this range may be a modifiable practice to improve outcomes.

Glycated albumin, not hemoglobin A1c, predicts cardiovascular hospitalization and length of stay in diabetic patients on dialysis

BACKGROUND

The utility of glycated hemoglobin (HbA1c) and glycated albumin (GA) in diabetic dialysis patients remains unknown. GA was previously associated with all-cause hospitalization and patient survival. Relationships between GA, HbA1c, and casual plasma glucose (PG) with cause-specific cardiovascular (CV) disease, infectious disease (ID), and vascular access- (VA) related hospitalization rates and length of stay (LOS) were assessed.

METHODS

444 prevalent diabetic dialysis patients had monthly PG, quarterly GA, and all HbA1c values recorded for 2.33 years; hospitalizations within 17 and 30 days of testing were evaluated. Best-fit, time-dependent Cox models were constructed in unadjusted, case-mix-adjusted (age, sex, race, BMI, diabetes duration, dialysis vintage), and case-mix- plus lab-adjusted (hemoglobin, albumin, phosphorus) models.

RESULTS

Mean ± SD diabetes duration was 18.5 ± 10.8 years and dialysis vintage 2.9 ± 2.6 years. In fully adjusted models, CV hospitalization rates were associated with increasing GA (HR 1.32; 95% CI 1.11-1.57; p = 0.002 at 17 days; HR 1.21; p = 0.02 at 30 days) and PG (HR 1.10; 95% CI 1.02-1.17; p = 0.01 at 17 days; HR 1.07; p = 0.03 at 30 days), not HbA1c (HR 1.24; 95% CI 0.89-1.73; p = 0.21 at 17 days; HR 1.26; p = 0.10 at 30 days). LOS for CV admissions was positively associated with GA (HR 1.18; 95% CI 1.01-1.39; p = 0.03), not PG (HR 1.04; 95% CI 0.99-1.10; p = 0.15) or HbA1c (HR 1.03; 95% CI 0.92-1.15; p = 0.21). Admissions due to ID and VA complications (and LOS) did not correlate with these assays.

CONCLUSIONS

Improved glycemic control based on GA and PG predicted CV-related hospitalizations; GA also predicted CV hospitalization LOS. HbA1c did not predict cause-specific hospitalizations in dialysis populations.

Glycemic control in diabetic dialysis patients and the burnt-out diabetes phenomenon

Diabetes mellitus (DM) is the most common cause of end-stage kidney disease and a major risk of morbidity and mortality. It is not clear whether medical management of DM has any significant beneficial effect on clinical outcomes at the end-stage of diabetic nephropathy with full-blown micro- and macro-angiopathic complications. Both loss of kidney function and dialysis treatment interfere with glucose homeostasis and confound glycemic control. Given the unique nature of uremic milieu and dialysis therapy related alterations, there have been some debates about reliance on the conventional measures of glycemic control, in particular the clinical relevance of hemoglobin A1c and its recommended target range of <7 % in diabetic dialysis patients. Moreover, a so-called burnt-out diabetes phenomenon has been described, in that many diabetic dialysis patients experience frequent hypoglycemic episodes prompting cessation of their anti-diabetic therapies transiently or even permanently. By reviewing the recent literature we argue that the use of A1c for management of diabetic dialysis patients should be encouraged if appropriate target ranges specific for these patients (e.g. 6 to 8 %) are used. We also argue that "burnt-out diabetes" is a true biologic phenomenon and highly prevalent in dialysis patients with established history and end-stage diabetic nephropathy and explore the role of protein-energy wasting to this end. Similarly, the J- or U-shaped associations between A1c or blood glucose concentrations and mortality are likely biologically plausible phenomena that should be taken into consideration in the management of diabetic dialysis patients to avoid hypoglycemia and its fatal consequences in diabetic dialysis patients.

A critical evaluation of glycated protein parameters in advanced nephropathy: a matter of life or death: A1C remains the gold standard outcome predictor in diabetic dialysis patients. Counterpoint

Chronic kidney disease remains as one of the major complications for individuals with diabetes and contributes to considerable morbidity. Individuals subjected to dialysis therapy, half of whom are diabetic, experience a mortality of ~20% per year. Understanding factors related to mortality remains a priority. Outside of dialysis units, A1C is unquestioned as the "gold standard" for glycemic control. In the recent past, however, there is evidence in large cohorts of diabetic dialysis patients that A1C at both the higher and lower levels was associated with mortality. Given the unique conditions associated with the metabolic dysregulation in dialysis patients, there is a critical need to identify accurate assays to monitor glycemic control to relate to cardiovascular endpoints. In this two-part point-counterpoint narrative, Drs. Freedman and Kalantar-Zadeh take opposing views on the utility of A1C in relation to cardiovascular disease and survival and as to consideration of use of other short-term markers in glycemia. In the narrative preceeding this counterpoint, Dr. Freedman suggests that glycated albumin may be the preferred glycemic marker in dialysis subjects. In the counterpoint narrative below, Dr. Kalantar-Zadeh defends the use of A1C as the unquestioned gold standard for glycemic management in dialysis subjects.

A critical evaluation of glycated protein parameters in advanced nephropathy: a matter of life or death: time to dispense with the hemoglobin A1C in end-stage kidney disease

Chronic kidney disease remains as one of the major complications for individuals with diabetes and contributes to considerable morbidity. Individuals subjected to dialysis therapy, half of whom are diabetic, experience a mortality of ~20% per year. Understanding factors related to mortality remains a priority. Outside of dialysis units, A1C is unquestioned as the "gold standard" for glycemic control. In the recent past, however, there is evidence in large cohorts of diabetic dialysis patients that A1C at both the higher and lower levels was associated with mortality. Given the unique conditions associated with the metabolic dysregulation in dialysis patients, there is a critical need to identify accurate assays to monitor glycemic control to relate to cardiovascular endpoints. In this two-part point-counterpoint narrative, Drs. Freedman and Kalantar-Zadeh take opposing views on the utility of A1C in relation to cardiovascular disease and survival and as to consideration of use of other short-term markers in glycemia. In the narrative below, Dr. Freedman suggests that glycated albumin may be the preferred glycemic marker in dialysis subjects. In the counterpoint narrative following Dr. Freedman's contribution, Dr. Kalantar-Zadeh defends the use of A1C as the unquestioned gold standard for glycemic management in dialysis subjects.

Glycemic control and survival in peritoneal dialysis patients with diabetes mellitus

PURPOSE

The optimal target for glycated hemoglobin (HbA1c) has not been well defined in peritoneal dialysis (PD) patients with diabetes mellitus.

METHODS

The objective of our study was to examine the predictive value of predialysis and time-averaged follow-up HbA1c values on technique and patient survival in diabetic PD patients treated in the Toronto General Hospital Home Peritoneal Dialysis Unit, between January 1, 2003 and December 31, 2008 with a median follow-up period of 30±23 months.

RESULTS

Ninety-one patients (mean age 64±13 years-old) were included in this retrospective study. Patients were followed between 3 and 91 months (mean duration 30±23 months). During this period, 40 patients died. We found no statistically significant correlation between baseline predialysis HbA1c values and technique and patient survival. Time-averaged follow-up HbA1c in increments<6.5%, 6.5-8%, and >8% showed no significant survival difference among groups.

CONCLUSIONS

There was no significant correlation of baseline and time-averaged follow-up HbA1c values with patient and PD technique survival.

Glycemic control and cardiovascular mortality in hemodialysis patients with diabetes: a 6-year cohort study

Previous observational studies using differing methodologies have yielded inconsistent results regarding the association between glycemic control and outcomes in diabetic patients receiving maintenance hemodialysis (MHD). We examined mortality predictability of A1C and random serum glucose over time in a contemporary cohort of 54,757 diabetic MHD patients (age 63 ± 13 years, 51% men, 30% African Americans, 19% Hispanics). Adjusted all-cause death hazard ratio (HR) for baseline A1C increments of 8.0-8.9, 9.0-9.9, and ≥10%, compared with 7.0-7.9% (reference), was 1.06 (95% CI 1.01-1.12), 1.05 (0.99-1.12), and 1.19 (1.12-1.28), respectively, and for time-averaged A1C was 1.11 (1.05-1.16), 1.36 (1.27-1.45), and 1.59 (1.46-1.72). A symmetric increase in mortality also occurred with time-averaged A1C levels in the low range (6.0-6.9%, HR 1.05 [95% CI 1.01-1.08]; 5.0-5.9%, 1.08 [1.04-1.11], and ≤5%, 1.35 [1.29-1.42]) compared with 7.0-7.9% in fully adjusted models. Adjusted all-cause death HR for time-averaged blood glucose 175-199, 200-249, 250-299, and ≥300 mg/dL, compared with 150-175 mg/dL (reference), was 1.03 (95% CI 0.99-1.07), 1.14 (1.10-1.19), 1.30 (1.23-1.37), and 1.66 (1.56-1.76), respectively. Hence, poor glycemic control (A1C ≥8% or serum glucose ≥200 mg/dL) appears to be associated with high all-cause and cardiovascular death in MHD patients. Very low glycemic levels are also associated with high mortality risk.

Good glycemic control is associated with better survival in diabetic patients on peritoneal dialysis: a prospective observational study

BACKGROUND

The effect of glycemic control after starting peritoneal dialysis (PD) on the survival of diabetic PD patients has largely been unexplored, especially in Asian population.

METHODS

We conducted a prospective observational study, in which 140 incident PD patients with diabetes were recruited. Patients were divided into tertiles according to the means of quarterly HbA1C levels measured during the first year after starting PD. We examined the association between HbA1C and all-cause mortality using Cox proportional hazards models.

RESULTS

The mean age was 58.7 years, 59.3% were male, and the mean follow-up duration was 3.5 years (range 0.4-9.5 years). The mean HbA1C levels were 6.3%, 7.1%, and 8.5% in the 1(st), 2(nd), and 3(rd) tertiles, respectively. Compared to the 1(st) tertile, the all-cause mortality rates were higher in the 2(nd) [hazard ratio (HR), 4.16; 95% confidence interval (CI), 0.91-18.94; p = 0.065] and significantly higher in the 3(rd) (HR, 13.16; 95% CI, 2.67-64.92; p = 0.002) tertiles (p for trend = 0.005), after adjusting for confounding factors. Cardiovascular mortality, however, did not differ significantly among the tertiles (p for trend = 0.682). In contrast, non-cardiovascular deaths, most of which were caused by infection, were more frequent in the 2(nd) (HR, 7.67; 95% CI, 0.68-86.37; p = 0.099) and the 3(rd) (HR, 51.24; 95% CI, 3.85-681.35; p = 0.003) tertiles than the 1(st) tertile (p for trend = 0.007).

CONCLUSIONS

Poor glycemic control is associated with high mortality rates in diabetic PD patients, suggesting that better glycemic control may improve the outcomes of these patients.

Association of pretransplant glycemic control with posttransplant outcomes in diabetic kidney transplant recipients

OBJECTIVE

Observational studies have yielded inconsistent findings regarding the association of hemoglobin A(1c) (HbA(1c)) with survival in diabetic patients on dialysis. The association between pretransplant glycemic control and short- and long-term posttransplant outcomes in kidney transplant recipients is not clear.

RESEARCH DESIGN AND METHODS

Linking the 5-year patient data of a large dialysis organization (DaVita) to the Scientific Registry of Transplant Recipients, we identified 2,872 diabetic dialysis patients who underwent first kidney transplantation. Mortality or graft failure and delayed graft function (DGF) risks were estimated by Cox regression (hazard ratio [HR]) and logistic regression (odds ratio), respectively.

RESULTS

Patients were 53 ± 11 years old and included 36% women and 24% African Americans. In our fully adjusted model, allograft failure-censored, all-cause death HR and 95% CI for time-averaged pretransplant HbA(1c) categories of 7 to <8%, 8 to <9%, 9 to 10%, and ≥10%, compared with 6 to <7% (reference), were 0.89 (0.59-1.36), 2.06 (1.31-3.24), 1.41 (0.73-2.74), and 3.43 (1.56-7.56), respectively; and graft failure-censored cardiovascular death HR was 0.38 (0.13-1.05), 1.78 (0.69-4.55), 1.59 (0.44-5.76), and 4.28 (0.85-21.64), respectively. We did not find any difference in risk of death-censored graft failure or DGF with different pretransplant HbA(1c) levels.

CONCLUSIONS

Poor pretransplant glycemic control appears associated with decreased posttransplant survival in kidney transplant recipients, whereas allograft outcomes may not be affected.

Glycated albumin is the preferred marker for assessing glycaemic control in advanced chronic kidney disease

Diabetic nephropathy is the most common aetiology of end-stage kidney disease (ESKD). Strict glycaemic control reduces the development and progression of diabetes-related complications, and there is evidence that improved metabolic control improves outcomes in diabetic subjects with advanced chronic kidney disease (CKD). Glycaemic control in people with kidney disease is complex. Changes in glucose and insulin homeostasis may occur as a consequence of loss of kidney function and dialysis. The reliability of measures of long-term glycaemic control is affected by CKD and the accuracy of glycated haemoglobin (HbA1c) in the setting of CKD and ESKD is questioned. Despite the altered character of diabetes in CKD, current guidelines for diabetes management are not specifically adjusted to this patient group. The validity of indicators of longer term glycaemic control has been the focus of increased recent research. This review discusses the current understanding of commonly used indicators of metabolic control (HbA1c, fructosamine, glycated albumin) in the setting of advanced CKD (Stages 4 and 5, glomerular filtration rate <30 mL/min/1.73m(2)).

Genetic variation in APOL1 associates with younger age at hemodialysis initiation

African Americans have a markedly higher incidence of ESRD compared with other racial groups. Two variants in the APOL1 gene, to date observed only among individuals of recent African ancestry, associate with increased risk for renal disease among African Americans. Here, we investigated whether these risk alleles also associate with age at initiation of chronic hemodialysis. We performed a cross-sectional study of 407 nondiabetic African Americans with ESRD who participated in the Accelerated Mortality on Renal Replacement (ArMORR) study, a prospective cohort of incident chronic hemodialysis patients. African Americans carrying two copies of the G1 risk allele initiated chronic hemodialysis at a mean age of 49.0 ± 14.9 years, which was significantly younger than both subjects with one copy of the G1 allele (55.9 ± 16.7 years; P = 0.014) and subjects without either risk allele (61.8 ± 17.1 years; P = 6.2 × 10(-7)). The association between the presence of the G1 allele and age at initiation of hemodialysis remained statistically significant after adjusting for sociodemographic and other potential confounders. We did not detect an association between the G2 risk allele and age at initiation of hemodialysis, but the sample size was limited. In conclusion, genetic variations in APOL1 identify African Americans that initiate chronic hemodialysis at a younger age. Early interventions to prevent progression of kidney disease may benefit this high-risk population.