Treatment of the diabetic patient: focus on cardiovascular and renal risk reduction

The futility of post-haemodialysis blood glucose levels: A retrospective cohort study

BACKGROUND

Frequent blood glucose tests are performed for people with diabetes receiving haemodialysis.

OBJECTIVES

To determine the rate of out-of-range post-haemodialysis blood glucose levels that are clinically acted upon, the intervention and outcome of each intervention, and the associations between post-haemodialysis blood glucose levels and relevant clinical predictors.

DESIGN

12-month retrospective cohort medical record review in one Australian haemodialysis centre. Post-haemodialysis blood glucose levels, prehaemodialysis blood glucose levels, time of treatment, diabetes medications, intradialytic fluid removal, dialysate dextrose concentration, clinical actions, interventions, and outcomes on out-of-range blood glucose levels were retrieved.

PARTICIPANTS

22 participants with a median time receiving dialysis 3.1 years (interquartile range 2.3-4.7).

MEASUREMENTS AND RESULTS

The proportion of out-of-range post-haemodialysis blood glucose levels was 87.3% (95% confidence interval, 86.1%-88.5%). No out-of-range post-haemodialysis blood glucose levels were clinically acted upon. Out-of-range post-haemodialysis blood glucose levels were 4.6 times more likely if a higher dextrose bath was used (95% confidence interval: 3.3; 6.3. p < 0.001). The odds of the post-haemodialysis blood glucose levels increased by each 1 mmol/L. Intradialytic fluid removal, dialysate dextrose concentration, sex, dialysis time, anti-hyperglycaemic agents were also associated with out-of-range post-haemodialysis blood glucose levels.

CONCLUSION

Routine post-haemodialysis blood glucose levels testing has limited clinical utility in care for people with diabetes receiving maintenance haemodialysis. Higher dextrose dialysate may require individual titration depending on prehaemodialysis blood glucose levels.

RhoA/ROCK inhibition attenuates endothelin-1-induced elevated glomerular permeability to albumin, inflammation, and fibrosis

Endothelin-1 (ET-1) contributes to the development of kidney diseases. However, the underlying molecular mechanism is largely undefined. Here we sought to investigate the potential role of ET-1 receptors, ET_A and ET_B in the regulation of increased glomerular permeability and underlying signaling pathways post-ET-1 infusion. Male Sprague-Dawley rats were infused with ET-1 (2 pmol/kg per minute, i.v.) for four weeks, and the effect on glomerular permeability to albumin (P_alb) and albuminuria was measured. The selective ROCK-1/2 inhibitor, Y-27632, was administered to a separate group of rats to determine its effect on ET-1-induced P_alb and albuminuria. The role of ET_A and ET_B receptors in regulating RhoA/ROCK activity was determined by incubating isolated glomeruli from normal rats with ET-1 and with selective ET_A and ET_B receptor antagonists. ET-1 infusion for four weeks significantly elevated P_alb and albuminuria. Y-27632 significantly reduced the elevation of P_alb and albuminuria. The activities of both RhoA and ROCK-1/2 were increased by ET-1 infusion. Selective ET_B receptor antagonism had no effect on the elevated activity of both RhoA and ROCK-1/2 enzymes. Selective ET_A receptor and combined ET_A/ET_B receptors blockade restored the activity of RhoA and ROCK-1/2 to normal levels. In addition, chronic ET-1 infusion increased the levels of glomerular inflammatory and fibrotic markers. These effects were all attenuated in rats following ROCK-1/2 inhibition. These observations suggest that ET-1 contributes to increased albuminuria, inflammation, and fibrosis by modulating the activity of the ET_A-RhoA/ROCK-1/2 pathway. Selective ET_A receptor blockade may represent a potential therapeutic strategy to limit glomerular injury and albuminuria in kidney disease.

Blood Glucose Fluctuation in Older Adults with Diabetes Mellitus and End-Stage Renal Disease on Maintenance Hemodialysis: An Observational Study

INTRODUCTION

Patients with diabetes mellitus and end-stage renal disease are at a high risk of developing coronary, cerebrovascular, and peripheral vascular diseases. This study aimed to characterize hypoglycemia and blood glucose fluctuations associated with maintenance hemodialysis in older adult patients with diabetes mellitus and end-stage renal disease using a continuous glucose monitoring system.

METHODS

Seven patients were enrolled in this study, and 13 pairs of continuous glucose monitoring system data were collected. Each pair included data of 1 dialysis-on day and 1 dialysis-off day. Information on basic patient characteristics, including age, diabetes mellitus duration, hemodialysis duration, and proportions of hemoglobin A1c and glycated albumin, were collected. Differences in blood glucose fluctuation were compared between dialysis-on days and dialysis-off days.

RESULTS

The mean blood glucose on dialysis-on days (6.96 ± 2.57 mmol/L) was significantly lower than that on dialysis-off days (7.68 ± 2.31 mmol/L; P < 0.05). In contrast, the following parameters had significantly higher values (all P < 0.05) on dialysis-on days compared to dialysis-off days: large amplitude of glycemic excursion level (5.82 ± 2.86 mmol/L versus 4.21 ± 1.71 mmol/L), large amplitude of glycemic excursion level from 8 a.m. to 2 p.m. (3.6 ± 1.74 mmol/L versus 2.8 ± 1.33 mmol/L), mean amplitude of glycemic excursion level (4.78 ± 1.68 mmol/L versus 3.89 ± 1.67 mmol/L), mean amplitude of glycemic excursion level from 8 a.m. to 2 p.m. (4.01 ± 1.03 mmol/L versus 3.12. ± 0.97 mmol/L), standard deviation of blood glucose (1.55 ± 0.89 mmol/L versus 1.03 ± 0.4 mmol/L), and time below a target glucose range of less than 3.9 mmol/L (8.27% versus 4.25%).

CONCLUSION

Fluctuations in blood glucose levels were larger on dialysis-on days, particularly from the start of hemodialysis to 2 h post-hemodialysis, than on dialysis-off days. Hypoglycemia, as indicated by the time below a target glucose range of less than 3.9 mmol/L, occurred more frequently on dialysis-on days than on dialysis-off days.

Continuous glucose monitoring in patients with type 2 diabetes on hemodialysis

Diabetic kidney disease is the leading cause of end-stage kidney disease in high-income countries. The strict control of glycemic oscillations is the principal therapeutic target, but this could be hard to achieve in uremic patients due to their unpredictable insulin sensitivity. Currently, the evaluation of the glycemic profile relies on serum markers (glycated hemoglobin HbA1c, glycated albumin, and fructosamine), capillary glucose blood control (self-monitoring of blood glucose), and interstitial glucose control (continue glucose monitoring). We conducted a systematic review of published articles on continue glucose monitoring in hemodialysis patients with type 2 diabetes, which included 12 major articles. Four studies found significant fluctuations in glucose levels during hemodialysis sessions. All studies reported a higher mean amplitude of glucose variations on the hemodialysis day. Three studies agreed that continue glucose monitoring is better than glycated hemoglobin in detecting these abnormalities. Moreover, continue glucose monitoring was more accurate and perceived as easier to use by patients and their caregivers. In patients with type 2 diabetes on hemodialysis, glucose levels show different variation patterns than the patients on hemodialysis without diabetes. Considering manageability, accuracy, and cost-effectiveness, continue glucose monitoring could be the ideal diagnostic tool for the patient with diabetes on hemodialysis.

Associations of Glycemic Control With Cardiovascular Outcomes Among US Hemodialysis Patients With Diabetes Mellitus

Background

There is a lack of data on the relationship between glycemic control and cardiovascular end points in hemodialysis patients with diabetes mellitus.

Methods and Results

We included adult Medicare‐insured patients with diabetes mellitus who initiated in‐center hemodialysis treatment from 2006 to 2008 and survived for >90 days. Quarterly mean time‐averaged glycated hemoglobin (HbA_1c) values were categorized into <48 mmol/mol (<6.5%) (reference), 48 to <58 mmol/mol (6.5% to <7.5%), 58 to <69 mmol/mol (7.5% to <8.5%), and ≥69 mmol/mol (≥8.5%). Medicare claims were used to identify outcomes of cardiovascular mortality, nonfatal myocardial infarction (MI), fatal or nonfatal MI, stroke, and peripheral arterial disease. We used Cox models as a function of time‐varying exposure to estimate multivariable adjusted hazard ratios and 95%CI for the associations between HbA_1c and time to study outcomes in a cohort of 16 387 eligible patients. Patients with HbA_1c 58 to <69 mmol/mol (7.5% to <8.5%) and ≥69 mmol/mol (≥8.5%) had 16% (CI, 2%, 32%) and 18% (CI, 1%, 37%) higher rates of cardiovascular mortality (P‐trend=0.01) and 16% (CI, 1%, 33%) and 15% (CI, 1%, 32%) higher rates of nonfatal MI (P‐trend=0.05), respectively, compared with those in the reference group. Patients with HbA_1c ≥69 mmol/mol (≥8.5%) had a 20% (CI, 2%, 41%) higher rate of fatal or nonfatal MI (P‐trend=0.02), compared with those in the reference group. HbA_1c was not associated with stroke, peripheral arterial disease, or all‐cause mortality.

Conclusions

Higher HbA_1c levels were significantly associated with higher rates of cardiovascular mortality and MI but not with stroke, peripheral arterial disease, or all‐cause mortality in this large cohort of hemodialysis patients with diabetes mellitus.

Correlates of poor glycemic control among patients with diabetes initiating hemodialysis for end-stage renal disease

Background

Maintaining tight glycemic control is important for prevention of diabetes-related outcomes in end-stage renal disease patients with diabetes, especially in light of their poor prognosis. This study aimed to determine factors associated with poor glycemic control among U.S. patients with diabetes mellitus initiating hemodialysis for end-stage renal disease.

Methods

Using data from the U.S. Renal Data System, electronic health records of a large national dialysis provider, and U.S. Census data, we performed a cross-sectional multivariable Poisson regression analysis to characterize risk factors associated with poor glycemic control, defined as glycated hemoglobin (HbA1c) >7 vs. ≤7 %, in adult patients with diabetes who initiated hemodialysis at an outpatient facility between 2006 and 2011.

Results

Of 16,297 patients with diabetes, 21.2 % had HbA1c >7 %. In multivariable analysis, younger patients, patients of Native American race, and those of Hispanic ethnicity had higher prevalence of poor glycemic control. Independent correlates of poor glycemic control further included higher platelet count, white blood cell count, and ferritin; higher body mass index, systolic blood pressure, total cholesterol and triglyceride concentrations; lower HDL and albumin concentrations; lower normalized protein catabolic rate; and higher estimated glomerular filtration rate at initiation of dialysis (all P < 0.05). No independent associations were found with area-level socioeconomic indicators. Occurrence of diabetes in patients <40 years of age, a proxy for type 1 diabetes, was associated with poor HbA1c control compared with that in patients ≥40 years of age, which was classified as type 2 diabetes. These findings were robust to the different outcome definitions of HbA1c >7.5 % and >8 %.

Conclusion

In this cohort of incident end-stage renal disease patients with diabetes, poor glycemic control was independently associated with younger age, Native American race, Hispanic ethnicity, higher body mass index, and clinical risk factors including atherogenic lipoprotein profile, hypertension, inflammation, and markers indicative of malnutrition and a more serious systemic disease.

The impact of the peritoneal glucose load index on hydration status and inflammation in peritoneal dialysis patients

Objective

To evaluate the impact of the peritoneal glucose load (PGL) on hydration status and inflammation in peritoneal dialysis (PD) patients.

Methods

This cross-sectional study evaluated stable PD patients using a novel PGL index (PGLI), which was calculated as the net glucose content (g) in the PD solutions administered in the daily PD prescription divided by the dry body weight (kg) assessed by whole-body bioimpedance spectroscopy. The relationship between PGLI and glycosylated haemoglobin (HbA1c), fluid overload (FO), and inflammatory markers was investigated.

Results

A total of 43 stable PD patients participated in the study. Significant positive correlations were found between PGLI and HbA1c, FO, plasma high sensitivity C-reactive protein (hsCRP), and plasma interleukin-6 (IL-6) levels. HbA1c, FO, plasma hsCRP and plasma IL-6 levels were significantly higher in patients with PGLI >3 g/kg/day compared with those with PGLI ≤3 g/kg/day.

Conclusions

PGLI values >3 g/kg/day may be associated with poor glycaemic control, over hydration and augmented inflammation. PGLI might be a useful tool for the quantitative assessment of the PGL and could be applied when managing PD patients.

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.

Glycemic control and survival in peritoneal dialysis patients with diabetes mellitus

BACKGROUND AND OBJECTIVES

The optimal target for glycemic control has not been established for diabetic peritoneal dialysis (PD) patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined mortality-predictability of hemoglobin A1c random serum glucose in a contemporary cohort of diabetic PD patients treated in DaVita dialysis clinics July 2001 through June 2006 with follow-up through June 2007.

RESULTS

We identified 2798 diabetic PD patients with A1c data. Serum glucose correlated with A1C (r=0.51). Adjusted all-cause death hazard ratio and 95% confidence interval for baseline A1c increments of 7.0 to 7.9%, 8.0 to 8.9%, 9.0 to 9.9%, and ≥10%, compared with 6.0 to 6.9% (reference), were 1.13 (0.97 to 1.32), 1.05 (0.88 to 1.27), 1.06 (0.84 to 1.34), and 1.48 (1.18 to 1.86); and for time-averaged A1c values were 1.10 (0.96 to 1.27), 1.28 (1.07 to 1.53), 1.34 (1.05 to 1.70), and 1.81 (1.33 to 2.46), respectively. The A1c-mortality association was modified by hemoglobin level such that higher all-cause mortality was evident only in nonanemic patients. Similar but non-significant trends in cardiovascular death risk was found across A1c increments. Adjusted all-cause death HR for time-averaged blood glucose 150 to 199, 200 to 249, 250 to 299, and ≥300 mg/dl, compared with 60 to 99 mg/dl (reference), were 1.02 (0.70 to 1.47), 1.12 (0.77 to 1.63), 1.45 (0.97 to 2.18), and 2.10 (1.37 to 3.20), respectively.

CONCLUSIONS

Poor glycemic control appears associated incrementally with higher mortality in PD patients. Moderate to severe hyperglycemia is associated with higher death risk especially in certain subgroups.

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

AIM

No suitable index or optimal target for diabetic control has been established for diabetic patients with end-stage renal disease (ESRD) undergoing haemodialysis. To address these issues, the single-centre observational study was conducted.

METHODS

Two hundred and forty-five diabetic ESRD patients (23.3% female; age at initiation of haemodialysis 61.7 ± 10.7 years) at start of haemodialysis between 1 January 1995 and 31 December 2004 were enrolled. Subjects were grouped according to glycaemic control level throughout the observational period as follows: mean postprandial plasma glucose (PPG) <8.9 mmol/L, 8.9 mmol/L ≤ PPG < 10.0 mmol/L, 10.0 mmol/L ≤ PPG < 11.1 mmol/L, 11.1 mmol/L ≤ PPG < 12.2 mmol/L and PPG ≥ 12.2 mmol/L; and HbA1c < 6.0%, 6.0-6.4%, 6.5-6.9% and ≥ 7.0%. Survival was then followed until 31 December 2005.

RESULTS

Cumulative survival of groups of 10.0 mmol/L ≤ PPG < 11.1 mmol/L, 11.1 ≤ PPG < 12.2 and PPG ≥ 12.2 mmol/L was significantly lower than that for PPG < 8.9 mmol/L as determined by Kaplan-Meier estimation (P = 0.016, 0.009 and 0.031, respectively; log-rank test). In both uni- and multivariate Cox proportional hazard models, mortality hazard ratios were significantly higher for PPG ≥ 10.0 mmol/L than for PPG < 8.9 mmol/L (P = 0.002-0.021). Kaplan-Meier survival curves grouped by HbA1c levels showed no correlation between HbA1c and survival during the observational period. No significant difference in mortality hazard ratios was seen for any HbA1c groups evaluated by Cox proportional hazard model.

CONCLUSION

Intensive management of diabetic control at a stringent mean on-study PPG < 10.0 mmol/L will improve the life expectancy in diabetic dialysis patients. However, no range of HbA1c values obtained in this study showed any clear difference in clinical outcomes.

Glycemic control and burnt-out diabetes in ESRD

Treatment of early diabetes mellitus, the most common cause of chronic kidney disease (CKD), may prevent or slow the progression of diabetic nephropathy and lower mortality and the incidence of cardiovascular disease in the general diabetic population and in patients with early stages of CKD. It is unclear whether glycemic control in patients with advanced CKD, including those with end-stage renal disease (ESRD) who undergo maintenance dialysis treatment is beneficial. Aside from the uncertain benefits of treatment in ESRD, hypoglycemic interventions in this population are also complicated by the complex changes in glucose homeostasis related to decreased kidney function and to dialytic therapies, occasionally leading to spontaneous resolution of hyperglycemia and normalization of hemoglobin A1c levels, a condition which might be termed "burnt-out diabetes." Further difficulties in ESRD are posed by the complicated pharmacokinetics of antidiabetic medications and the serious flaws in our available diagnostic tools used for monitoring long-term glycemic control. We review the physiology and pathophysiology of glucose homeostasis in advanced CKD and ESRD, the available antidiabetic medications and their specifics related to kidney function, and the diagnostic tools used to monitor the severity of hyperglycemia and the therapeutic effects of available treatments, along with their deficiencies in ESRD. We also review the concept of burnt-out diabetes and summarize the findings of studies that examined outcomes related to glycemic control in diabetic ESRD patients, and emphasize areas in need of further research.

A1C and survival in maintenance hemodialysis patients

OBJECTIVE

The optimal target for glycemic control has not been established in diabetic dialysis patients.

RESEARCH DESIGN AND METHODS

To address this question, the national database of a large dialysis organization (DaVita) was analyzed via time-dependent survival models with repeated measures.

RESULTS

Of 82,933 patients undergoing maintenance hemodialysis (MHD) in DaVita outpatient clinics over 3 years (July 2001 through June 2004), 23,618 diabetic MHD patients had A1C measurements at least once. Unadjusted survival analyses indicated paradoxically lower death hazard ratios (HRs) with higher A1C values. However, after adjusting for potential confounders (demographics, dialysis vintage, dose, comorbidity, anemia, and surrogates of malnutrition and inflammation), higher A1C values were incrementally associated with higher death risks. Compared with A1C in the 5-6% range, the adjusted all-cause and cardiovascular death HRs for A1C > or = 10% were 1.41 (95% CI 1.25-1.60) and 1.73 (1.44-2.08), respectively (P < 0.001). The incremental increase in death risk for rising A1C values was monotonic and robust in nonanemic patients (hemoglobin > 11.0 g/dl). In subgroup analyses, the association between A1C > 6% and increased death risk was more prominent among younger patients, those who had undergone dialysis for > 2 years, and those with higher protein intake (> 1 g x kg(-1) x day(-1)), blood hemoglobin (> 11 g/dl), or serum ferritin values (> 500 ng/ml).

CONCLUSIONS

In diabetic MHD patients, the apparently counterintuitive association between poor glycemic control and greater survival is explained by such confounders as malnutrition and anemia. All things equal, higher A1C is associated with increased death risk. Lower A1C levels not related to malnutrition or anemia appear to be associated with improved survival in MHD patients.

The first hypertension trial comparing the effects of two fixed-dose combination therapy regimens on cardiovascular events: Avoiding Cardiovascular events through Combination therapy in Patients Living with Systolic Hypertension (ACCOMPLISH)

Current recommendations for the treatment of hypertension clarify the need to achieve lower blood pressure levels in the general population (<140/90 mm Hg) and in specific high-risk patient groups such as patients with diabetes or chronic renal disease (<130/80 mm Hg). Further, it is evident that to reach appropriate blood pressure control, most patients with high blood pressure will require two or more antihypertensive agents. There is scarce clinical trial outcome evidence to guide clinicians in the selection of optimal combinations of antihypertensive classes for high-risk hypertensive patients. A new clinical trial, Avoiding Cardiovascular Events through Combination Therapy in Patients Living with Systolic Hypertension (ACCOMPLISH), is the first large clinical trial to directly compare cardiovascular mortality and morbidity rates for two fixed-dose combination therapies. Results from ACCOMPLISH should provide much-needed guidance for selecting optimal combination therapy for high-risk hypertensive patients.