Stringent glycaemic control prolongs survival in diabetic patients with end-stage renal disease on haemodialysis

Effects of DPP-4 Inhibitors on Blood Glucose Variability in Japanese Patients with Type 2 Diabetes on Maintenance Hemodialysis: A Prospective Observational Exploratory Study

INTRODUCTION

The precise blood glucose (BG) profile of hemodialysis patients is unclear, as is the effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors in hemodialysis patients with type 2 diabetes. Here, we used continuous glucose monitoring (CGM) to evaluate BG variability in these patients and to assess the efficacy of DPP-4 inhibitors, particularly during hemodialysis sessions and at nighttime (UMIN000012638).

METHODS

We examined BG profiles using CGM in 31 maintenance hemodialysis patients with type 2 diabetes. Differences between patients with and without DPP-4 inhibitors (n = 15 and 16, respectively) were analyzed using a linear mixed-effects model to assess changes in glucose levels in 5-min intervals.

RESULTS

The model revealed that DPP-4 inhibitor use was significantly associated with suppression of a rapid drop in glucose levels, both with and without adjustment for BG levels at the start of hemodialysis. Moreover, the model revealed that the two groups differed significantly in the pattern of changes in BG levels from 0:00 to 6:55 am. DPP-4 inhibitors suppressed the tendency for subsequent nocturnal hypoglycemia.

CONCLUSIONS

This prospective observational exploratory study showed that DPP-4 inhibitors could suppress BG variability during hemodialysis sessions as well as subsequent nocturnal changes in patients with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, UMIN000012638.

Modified creatinine index and risk for cardiovascular events and all-cause mortality in patients undergoing hemodialysis: The Q-Cohort study

BACKGROUND AND AIMS

The modified creatinine (Cr) index, calculated by age, sex, pre-dialysis serum Cr levels, and Kt/V for urea, reflects skeletal muscle mass in patients on hemodialysis. Whether the modified Cr index is associated with cardiovascular events and all-cause mortality remains unknown.

METHODS

A total of 3027 patients registered in the Q-Cohort Study, a multicenter, prospective study of patients on hemodialysis in Japan, were analyzed. The main outcomes were cardiovascular events and all-cause mortality. Associations between sex-specific quartiles of the modified Cr index and outcomes were analyzed by the Cox proportional hazard models and the Fine-Gray proportional subdistribution hazards model.

RESULTS

The modified Cr index was correlated with known nutritional and inflammatory markers. During a 4-year follow-up, 499 patients died of any cause, 372 experienced heart disease, and 194 developed stroke. The risk for all-cause mortality was significantly higher in the lower quartiles (Q1 and Q2) than in the highest quartile (Q4) as the reference group (hazard ratios and 95% confidence intervals: Q1, 2.65 [1.69-4.25], Q2, 1.92 [1.27-2.94], and Q3, 1.31 [0.87-2.02]). The risk of heart disease was significantly higher in Q1 than in Q4 (hazard ratios and 95% confidence intervals: Q1, 1.64 [1.04-2.61], Q2, 1.34 [0.91-2.00], and Q3, 1.04 [0.71-1.52]). The risk of stroke was not associated with the modified Cr index.

CONCLUSIONS

A lower modified Cr index is associated with an increased risk for heart disease and all-cause mortality, but not with the risk for stroke in patients on hemodialysis.

Distinct biomarker roles for HbA1c and glycated albumin in patients with type 2 diabetes on hemodialysis

AIMS

HbA_1c and glycated albumin (GA) are used to monitor glycemia, but their accuracy to represent glycemic profiles in hemodialysis remains controversial.

METHODS

Continuous glucose monitoring in 97 patients with type 2 diabetes (41 on hemodialysis [HD] and 56 without nephropathy) was analyzed to evaluate whether HbA_1c and/or GA serve as appropriate glycemic profile markers.

RESULTS

The average glucose significantly correlated with HbA_1c in both HD group and group without nephropathy (r=0.59, P<0.0001; r=0.40, P<0.005). The slopes of linear regression lines were statistically indistinguishable (F=0.30, P=0.744), while the y-intercepts were significantly different (F=57.86, P<0.0001). GA showed strong correlation with the glycemic standard deviation (r=0.68, P<0.0001), and with the average glucose (r=0.42, P<0.001). Least square analysis revealed that only HbA_1c, but not GA, was significantly associated with the average glucose (F=10.20, P<0.0005; F=0.38, P=0.5427), while only GA was significantly associated with the glycemic variability in HD group.

CONCLUSIONS

In HD participants, HbA_1c correlates with the average glucose more than GA, but underestimates it, and a correction formula of HbA1c can be developed as an appreciable marker. GA value itself reflects the average glucose, but less accurately than HbA_1c, while it could serve as an indicator for hyperglycemia/hypoglycemia excursion.

Determinant Effects of Average Fasting Plasma Glucose on Mortality in Diabetic End-Stage Renal Disease Patients on Maintenance Hemodialysis

Introduction

Diabetic kidney disease is an increasingly frequent cause of end-stage renal disease. However, mixed results were shown between glycated hemoglobin and mortality.

Methods

We used the average fasting plasma glucose (FPG) levels to predict mortality rates in long-term hemodialysis patients. We enrolled 46,332 hemodialysis patients with diabetes mellitus, who were registered in the Taiwan Renal Registry Data System between January 2005 and December 2012. The patients were stratified based on the quartiles of average FPG levels measured for the first (1-year FPG) and third years (3-year FPG) of hemodialysis. Survival analysis was conducted via multivariable Cox regression.

Results

After the first year of hemodialysis, the mean FPG levels were 103.5 ± 14.5, 144.7 ± 11.5, 189.6 ± 15.2, and 280.8 ± 1.2 mg/dl for the first, second, third, and fourth quartile, respectively. The Kaplan-Meier curve showed an incremental reduction in the survival as FPG levels increased (P < 0.0001). In the Cox regression model, the adjusted hazard ratios were 1.15 (95% CI: 1.10–1.20), 1.30 (95% CI: 1.25–1.36), and 1.45 (95% CI: 1.39–1.51) for the pairwise comparisons between the first quartile and the second, third, and fourth quartile, respectively. Similar trends were observed by 3-year FPG. Patients whose FPG levels increased had a 22% increased risk (95% CI: 1.16–1.29) for all-cause mortality compared with patients whose FPG levels decreased.

Discussion

Our results suggest that the average FPG levels are useful predictors of all-cause mortality in dialysis patients. In addition, an increasing trend in average FPG levels indicates poor survival.

Effects of teneligliptin on PDMPs and PAI-1 in patients with diabetes on hemodialysis

Background

Cardiovascular disease (CVD) is the main cause of death among hemodialysis (HD) patients. The effects of the dipeptidyl peptidase-4 inhibitor teneligliptin on CVD-related biomarkers in patients with type 2 diabetes mellitus (T2DM) receiving HD treatment are poorly understood. To determine whether teneligliptin has anti-CVD properties, we assessed its effects on soluble P-selectin (sP-selectin), platelet-derived microparticles (PDMPs), plasminogen activator inhibitor 1 (PAI-1), soluble E-selectin (sE-selectin), soluble vascular adhesion molecule 1 (sVCAM-1), and adiponectin plasma levels in HD and non-HD patients with T2DM.

Methods

Patients with T2DM eligible for teneligliptin monotherapy or combination therapy (eg, teneligliptin plus a sulfonylurea) were administered teneligliptin (20 mg/d) once daily for 6 months. Plasma levels of sP-selectin, PDMPs, PAI-1, sE-selectin, sVCAM-1, and adiponectin were measured by enzyme-linked immunosorbent assay at baseline and after 3 months and 6 months of treatment.

Results

Teneligliptin therapy significantly reduced plasma levels of sP-selectin, PDMPs, and PAI-1 compared with baseline levels, while significantly increasing adiponectin levels. sE-selectin and sVCAM-1 levels were significantly decreased only at 6 months. The reduction in sP-selectin, PDMPs, and PAI-1 was more significant in HD patients than in non-HD patients. However, the improvement in adiponectin levels was unchanged with HD treatment.

Conclusion

By modulating PDMPs or PAI-1, teneligliptin shows an antiatherothrombotic effect that may be beneficial in the primary prevention of CVD in patients with T2DM on HD.

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.

Diabetes therapies in hemodialysis patients: Dipeptidase-4 inhibitors

Although several previous studies have been published on the effects of dipeptidase-4 (DPP-4) inhibitors in diabetic hemodialysis (HD) patients, the findings have yet to be reviewed comprehensively. Eyesight failure caused by diabetic retinopathy and aging-related dementia make multiple daily insulin injections difficult for HD patients. Therefore, we reviewed the effects of DPP-4 inhibitors with a focus on oral antidiabetic drugs as a new treatment strategy in HD patients with diabetes. The following 7 DPP-4 inhibitors are available worldwide: sitagliptin, vildagliptin, alogliptin, linagliptin, teneligliptin, anagliptin, and saxagliptin. All of these are administered once daily with dose adjustments in HD patients. Four types of oral antidiabetic drugs can be administered for combination oral therapy with DPP-4 inhibitors, including sulfonylureas, meglitinide, thiazolidinediones, and alpha-glucosidase inhibitor. Nine studies examined the antidiabetic effects in HD patients. Treatments decreased hemoglobin A1c and glycated albumin levels by 0.3% to 1.3% and 1.7% to 4.9%, respectively. The efficacy of DPP-4 inhibitor treatment is high among HD patients, and no patients exhibited significant severe adverse effects such as hypoglycemia and liver dysfunction. DPP-4 inhibitors are key drugs in new treatment strategies for HD patients with diabetes and with limited choices for diabetes treatment.

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 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.

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.

Anti-inflammatory effects of linagliptin in hemodialysis patients with diabetes

Inflammation and glycemic control are important prognosis-related factors for hemodialysis (HD) patients; moreover, inflammation affects insulin secretion. Here, we evaluated the anti-inflammatory effects of monotherapy with linagliptin-a dipeptidase-4 inhibitor-in HD patients with type 2 diabetes. We examined 21 diabetic HD patients who were not receiving oral diabetes drugs or insulin therapy and with poor glycemic control (glycated albumin [GA] level, >20%). Linagliptin (5 mg) was administered to the patients daily. The levels of prostaglandin E2 (PGE2), interleukin-6 (IL-6), high-sensitivity C-reactive protein, GA, blood glucose, and active glucagon-like peptide-1 were determined before and 6 months after treatment. Body weight and serum levels of albumin, hemoglobin, total cholesterol, and low-density lipoprotein cholesterol were also recorded before and after treatment. The levels of PGE2 and GA were significantly decreased 1 month after starting linagliptin therapy, whereas the IL-6 levels were significantly decreased 6 months after starting linagliptin therapy. After 6 months of treatment, the PGE2 levels decreased from 188 ± 50 ng/mL to 26 ± 5 ng/mL; IL-6 levels, from 1.5 ± 0.4 pg/mL to 0.6 ± 0.1 pg/mL; and GA levels, from 21.3% ± 0.6% to 18.0% ± 0.6%. Glucagon-like peptide-1 levels increased 2.5-fold during the treatment. Over the 6-month treatment period, body weight and levels of high-sensitivity C-reactive protein, blood glucose, albumin, hemoglobin, and cholesterol did not change; none of the patients exhibited hypoglycemia. The anti-inflammatory effects of linagliptin monotherapy indicate that it may serve as a useful glucose control strategy for HD patients with diabetes.

Vildagliptin is Effective for Glycemic Control in Diabetic Patients Undergoing either Hemodialysis or Peritoneal Dialysis

INTRODUCTION

Vildagliptin can be used in patients with type 2 diabetes mellitus and renal impairment. However, there have been few reports investigating the clinical effectiveness of vildagliptin in diabetic patients undergoing hemodialysis. No previous studies have evaluated the use of vildagliptin in patients undergoing peritoneal dialysis. The authors determined the usefulness of vildagliptin for treating type 2 diabetic patients receiving chronic dialysis, including peritoneal dialysis.

METHODS

A retrospective study of ten diabetic patients undergoing peritoneal dialysis and five diabetic patients undergoing hemodialysis who were treated with 50 mg/day of vildagliptin was performed. Clinical parameters were investigated for a period of 6 months starting from the vildagliptin therapy.

RESULTS

The hemoglobin A1c (HbA1c) levels were significantly reduced after baseline in both the peritoneal dialysis and hemodialysis groups, whereas the hemoglobin levels did not change during the follow-up period. The mean change in the HbA1c level (ΔHbA1c) was -0.6 ± 0.9% and -0.5 ± 0.7% among the patients undergoing peritoneal dialysis and hemodialysis, respectively. The glycated albumin (GA) levels were also significantly reduced compared with baseline in the peritoneal dialysis group, although the serum albumin levels did not change. The mean change in the GA level (ΔGA) was -3.4 ± 3.1% and -2.1 ± 2.5% among the patients undergoing peritoneal dialysis and hemodialysis, respectively. Stepwise multivariate analyses demonstrated the level of HbA1c at baseline to be significantly associated with the ΔHbA1c and that the level of GA at baseline was significantly associated with the ΔGA.

CONCLUSION

Vildagliptin exhibits effectiveness in patients with type 2 diabetes mellitus undergoing peritoneal dialysis or hemodialysis. The degree of improvement in the HbA1c and GA levels was dependent on these levels at baseline, similar to the findings of previous reports of subjects without end-stage kidney disease.

Glycated albumin predicts the risk of mortality in type 2 diabetic patients on hemodialysis: evaluation of a target level for improving survival

Glycated albumin (GA) is considered a more reliable marker than glycated hemoglobin (HbA1c) for monitoring glycemic control, particularly in diabetic hemodialysis patients. We investigated the associations of GA, HbA1c, and random serum glucose levels with survival, and evaluated possible targets for improving survival in diabetic hemodialysis patients. In this prospective, longitudinal, observational study, we enrolled 90 diabetic hemodialysis patients across six dialysis centers in Japan. The median duration of follow-up was 36.0 months (mean follow-up, 29.8 months; range, 3-36 months). There were 11 deaths during the observation period. GA was a significant predictor for mortality (hazard ratio, 1.143 per 1% increase in GA; 95% confidence interval, 1.011-1.292; P = 0.033), whereas HbA1c and random glucose levels were not predictors for mortality. Receiver operating characteristics curve analysis showed that the cutoff value of GA for predicting the risk of mortality was 25%. In the Kaplan-Meier analysis, the cumulative survival rate was significantly greater in patients with GA ≤ 25% than in patients with GA >25%. GA predicted the risk of all-cause and cardiovascular mortality in diabetic hemodialysis patients. Our results suggest that GA ≤ 25% is an appropriate target for improving survival in diabetic hemodialysis patients.

Long-term effects of alogliptin benzoate in hemodialysis patients with diabetes: a 2-year study

AIM

To evaluate the long-term efficacy of monotherapy with the dipeptidase-4 inhibitor alogliptin benzoate in hemodialysis (HD) patients with type 2 diabetes.

METHODS

Sixteen diabetic HD patients with inadequate glycemic control (hemoglobin A1c (HbA1c) level >6.5% and glycated albumin (GA) level >20%) on diet and exercise participated in the study. No patients were taking other oral antidiabetic drugs or receiving insulin therapy. Alogliptin 6.25 mg was administered to patients once daily. HbA1c, GA levels were obtained before and after 2 years of treatment. Body weight and active glucagon-like peptide-1, blood glucose, insulin, C-peptide immunoreactivity, glucagon, albumin, hemoglobin, and total cholesterol levels were also examined before and after treatment.

RESULTS

Both HbA1c and GA levels decreased after starting alogliptin administration. As compared to the pretreatment levels, HbA1c and GA levels significantly decreased at 3 and 18 months, respectively, after starting alogliptin administration. HbA1c and GA levels decreased from 7.1 ± 0.2 to 5.8 ± 1.6% and from 22.5 ± 0.7 to 19.6 ± 0.6%, respectively, 24 months after beginning treatment. Glucagon-like peptide-1 levels (8.9 ± 5.7 pmol/l before treatment) doubled after treatment. Body weight and blood glucose, insulin, C-peptide immunoreactivity, glucagon, albumin, hemoglobin, and total cholesterol levels did not change with treatment. Only one significant adverse effect, a drug-related rash, was seen in 1 patient.

CONCLUSION

Long-term (2-year) effects of alogliptin benzoate monotherapy suggest its efficacy as a new treatment strategy in diabetic HD patients.

Developing an HbA(1c)-based equation to estimate blood glucose in maintenance hemodialysis patients

OBJECTIVE

Hemoglobin A1c (HbA(1c)) has been widely used as a clinically important assessment tool for outcome analyses related to glycemic control. However, because of special conditions in dialysis patients, including the uremic milieu, there is no HbA(1c) blood glucose (BG) equation specific for patients on dialysis. In this study, we sought to develop HbA(1c)-BG equation models for hemodialysis patients.

RESEARCH DESIGN AND METHODS

We examined associations between HbA(1c) and random serum BG over time in a contemporary cohort of diabetic patients with hemodialysis treated in DaVita dialysis clinics. We identified 11,986 patients (63 ± 12 years old and 49% male) with 69,764 paired measurements of HbA(1c) and BG over the course of 5 years (2001-2006). Bootstrapping method was used to estimate average BG and corresponding HbA(1c) levels. The association was adjusted by patient factors using linear regression.

RESULTS

Linear regression analyses yielded the following three regression equations: BG = 59.2 + 29.4 × HbA(1c) - 20.8 × Alb (R(2) = 0.483); BG = 104.8 + 29.7 × HbA(1c) - 18.4 × Alb - 4.7 × Hb (R(2) = 0.486); and BG = 82.9 + 30.7 × HbA(1c) - 16.5 × Alb - 5.4 × Hb + 0.3 × age + race (R(2) = 0.491). All our models showed stronger association than previous equation models (R(2) = 0.468 in the Diabetes Control and Complications Trial and A1c-Derived Average Glucose equations).

CONCLUSIONS

The association between HbA(1c) and BG in hemodialysis patients is different than that of patients with normal kidney function. Our analysis suggests that equations including serum albumin or hemoglobin are better for hemodialysis patients.

The dipeptidyl peptidase-4 inhibitor alogliptin improves glycemic control in type 2 diabetic patients undergoing hemodialysis

OBJECTIVES

The potent and selective dipeptidyl peptidase-4 (DPP-4) inhibitor alogliptin improves glycemic control in patients with type 2 diabetes through incretin hormone-mediated increases in both α- and β-cell responsiveness to glucose. In this study, the efficacy and safety of alogliptin in type 2 diabetic patients undergoing hemodialysis (HD) were evaluated.

METHODS

A prospective, open-label study of 30 patients (male/female: 24/6; mean age: 69.7 ± 1.7 years) with type 2 diabetes who were undergoing HD without insulin injection therapy was conducted. Patients were administered 6.25 mg/day alogliptin and efficacy and safety were determined by monitoring clinical and laboratory parameters during the 48-week study period.

RESULTS

After 48 weeks, alogliptin had decreased postprandial plasma glucose levels from 212 ± 8 mg/dL baseline to 156 ± 7 mg/dL, hemoglobin A1c levels from 7.1 ± 0.2% baseline to 6.3 ± 0.2% and glycated albumin (GA) levels from 25.6 ± 0.6% baseline to 20.7 ± 0.4% (all p < 0.0001). Alogliptin efficacy did not differ according to median age or body mass index, but the GA reduction was significantly greater in the antidiabetic agents-naïve group. The magnitude of GA reduction was baseline GA-dependent, being greater at higher baseline GA levels. No serious adverse effects, such as hypoglycemia or liver impairment, were observed in any patient.

CONCLUSION

Alogliptin as monotherapy or in combination with other oral antidiabetic agents improved glycemic control and was generally well tolerated in patients with HD over a 48-week period.

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 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.

Estimating average glucose levels from glycated albumin in patients with end-stage renal disease

PURPOSE

In patients with diabetic end stage renal disease (ESRD), glycated albumin (GA) reflects recent glycemic control more accurately than glycated hemoglobin (HbA1c). We evaluated the relationship between GA and average blood glucose (AG) level and developed an estimating equation for translating GA values into easier-to-understand AG levels.

MATERIALS AND METHODS

A total of 185 ESRD patients, including 154 diabetic and 31 non-diabetic participants, were enrolled (108 hemodialysis, 77 peritoneal dialysis). Patients were asked to perform four-point daily self-monitoring of capillary blood glucose (SMBG) at least three consecutive days each week for four weeks. Serum levels of GA, HbA1c and other biochemical parameters were checked at baseline, as well as at 4 and 8 weeks.

RESULTS

Approximately 74.3±7.0 SMBG readings were obtained from each participant and mean AG was 169.1±48.2 mg/dL. The correlation coefficient between serum GA and AG levels (r=0.70, p<0.001) was higher than that of HbA1c and AG (r=0.54, p<0.001). Linear regression analysis yielded the following equation: estimated AG (eAG) (mg/dL)=4.71×GA%+73.35, and with this formula, serum GA levels could be easily translated to eAG levels. Multivariate analysis revealed significant contributions of postprandial hyperglycemia (β=0.25, p=0.03) and serum albumin (β=0.17, p=0.04) in determining serum GA level, independent to other clinical parameters.

CONCLUSION

Compared to HbA1c, serum GA levels were better correlated with AG levels. Using the estimating equation, an average blood glucose level of 155-160 mg/dL could be matched to a GA value of 18-19% in patients with ESRD.

Association of HbA1c values with mortality and cardiovascular events in diabetic dialysis patients. The INVOR study and review of the literature

Background

Improved glycemic control reduces complications in patients with diabetes mellitus (DM). However, it is discussed controversially whether patients with diabetes mellitus and end-stage renal disease benefit from strict glycemic control.

Methods

We followed 78 patients with DM initiating dialysis treatment of the region of Vorarlberg in a prospective cohort study applying a time-dependent Cox regression analysis using all measured laboratory values for up to more than seven years. This resulted in 880 HbA_1c measurements (with one measurement every 3.16 patient months on average) during the entire observation period. Non-linear P-splines were used to allow flexible modeling of the association with mortality and cardiovascular disease (CVD) events.

Results

We observed a decreased mortality risk with increasing HbA_1c values (HR = 0.72 per 1% increase, p = 0.024). Adjustment for age and sex and additional adjustment for other CVD risk factors only slightly attenuated the association (HR = 0.71, p = 0.044). A non-linear P-spline showed that the association did not follow a fully linear pattern with a highly significant non-linear component (p = 0.001) with an increased risk of all-cause mortality for HbA_1c values up to 6–7%. Causes of death were associated with HbA_1c values. The risk for CVD events, however, increased with increasing HbA_1c values (HR = 1.24 per 1% increase, p = 0.048) but vanished after extended adjustments.

Conclusions

This study considered the entire information collected on HbA_1c over a period of more than seven years. Besides the methodological advantages our data indicate a significant inverse association between HbA_1c levels and all-cause mortality. However, for CVD events no significant association could be found.

The dipeptidyl peptidase-4 (DPP-4) inhibitor vildagliptin improves glycemic control in type 2 diabetic patients undergoing hemodialysis

The potent and selective dipeptidyl peptidase-4 inhibitor vildagliptin improves glycemic control in patients with type 2 diabetes through incretin hormone-mediated increases in both α- and β-cell responsiveness to glucose. We conducted a prospective, open-label, parallel group, controlled study of 51 patients with type 2 diabetic patients undergoing hemodialysis (HD) during the 24-week study period. Patients were assigned to two groups: the vildagliptin group (n = 30) and the control group (n = 21). Vildagliptin was administered at 50 mg/day for the first 8 weeks. Then doses were titrated by dose-doubling to a maximum of 100 mg/day if hemoglobin A1c (HbA1c) or glycated albumin (GA) target levels had not been reached. No vildagliptin was administered to the controls. The average final dose of vildagliptin was 80 ± 5 mg daily. After 24 weeks, vildagliptin had decreased average HbA1c levels from 6.7 % baseline to 6.1 %, average GA levels from 24.5 % baseline to 20.5 % and average postprandial plasma glucose levels from 186 mg/dL baseline to 140 mg/dL (all p < 0.0001). In the control group, we observed no such changes. Vildagliptin efficacy did not differ according to age or body mass index, but the GA reduction was significantly greater in the anti-diabetic agents-naïve group. Furthermore, in patients with higher baseline GA levels, a higher vildagliptin dosage was required to produce a noticeable effect. No serious adverse effects such as hypoglycemia or liver impairment were observed in any patient. Vildagliptin was effective as a treatment for diabetic patients undergoing HD.