Should Pre-Transplant Hemoglobin A1c Be Used to Predict Post-Transplant Compliance in End-Stage Renal Disease Patients Undergoing Kidney Transplantation?

Background

Patient compliance with immunosuppressive therapy after transplant has impacts on both graft and patient outcomes. For diabetic end-stage renal disease (ESRD) patients who are undergoing evaluation for kidney transplantation in our program, hemoglobin A_1c (HbA_1c) level of >10% is used as a flag that the patient may be at risk for noncompliance and that more comprehensive psychosocial screening is needed prior to transplant. We evaluated the association between pre-transplant HbA_1c level and post-transplant compliance, as no study to date has looked at this in the transplant population.

Material/Methods

The charts of 392 patients who received a kidney transplant at a single institution between July 2008 and June 2012 were retrospectively reviewed. One hundred and sixty-five diabetic patients who received a kidney transplant alone were included in the final analysis. Our predictive variable was HbA_1c level greater than 7.7% based on previous reports in the diabetic population. Outcome measures were graft survival, rejection episodes, unexplained low immunosuppressant levels, and documented noncompliance.

Results

There were no statistically significant differences between the HbA_1c groups of ≤7.7% and >7.7% in outcomes of failed grafts (22.0% and 17.8%, p=0.2), rejection episodes (15.0% and 6.7%, p=0.3), unexplained low immunosuppressant level (46.6% and 37.9%, p=0.3), and documented noncompliance (25.0% and 16.7%, p=0.4).

Conclusions

In diabetic ESRD patients selected for renal transplantation, elevated pre-transplant HbA_1c levels, defined as HbA_1c >7.7%, are not predictive of post-transplant medication compliance. We advocate that this group of patients should not be denied transplant solely on their elevated pre-transplant HbA_1c.

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.

Monitoring HIV-infected Patients with Diabetes: Hemoglobin A1c, Fructosamine, or Glucose?

BACKGROUND

Published studies report inappropriately low hemoglobin A1C (HbA1c) values that underestimate glycemia in HIV patients.

METHODS

We reviewed the charts of all HIV patients with diabetes mellitus (DM) at our clinic. Fifty-nine patients had HbA1c data, of whom 26 patients also had fructosamine data. We compared the most recent HbA1c to finger-stick (FS) glucose averaged over three months, and fructosamine to FS averaged over six weeks. Predicted average glucose (pAG) was calculated as reported by Nathan et al: pAG (mg/dL) = 28.7 × A1C% − 46.7. Data were analyzed using the Statistical Analysis System (SAS) and Kruskal–Wallis test.

RESULTS

HbA1c values underestimated (UE) actual average glucose (aAG) in 19% of these patients and overestimated (OE) aAG in 27%. HbA1c estimated aAG within the established range in only 54% of the patients. There were no statistical differences in the types of HIV medication used in patients with UE, OE, or accurately estimated (AE) glycemia. A Spearman correlation coefficient between HbA1c and aAG was r = 0.53 (P < 0.0001). Correlation between fructosamine and aAG was r = 0.47 (P = 0.016).

CONCLUSIONS

The correlations between HbA1c and aAG and between fructosamine and aAG were weaker than expected, and fructosamine was not more accurate than HbA1c.

[Significance of hemoglobin A1C in the management of diabetes in dialysis patients]

According to latest guidelines hemoglobin A1C plays a central role in the diagnosis of diabetes mellitus. It is well-known from epidemiologic studies that a high rate of diabetic patients enters into dialysis programs and these patients have an unfavourable mortality outcome. Based on surveys conducted in recent years in this patient group, hemoglobin A1C has an important role in assessing carbohydrate metabolism. However, there are several factors independent of blood glucose may affect hemoglobin A1C values both in hemodialysis and peritoneal dialysis patients. Hemodialysis disturbs hemoglobin A1c assessment because of an accelerated turnover of lost red blood cells. During peritoneal dialysis a considerable amount of glucose may be absorbed from the peritoneal solutions that may influence hemoglobin A1C level. Several alternative markers such as glycated albumin and fructosamine have been evaluated but they failed to have prognostic advantage. It has been concluded that among dialysis patients the hemoglobin A1C range between 6.5 and 8% is associated with the lowest mortality risk.

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.

The economic burden of progressive chronic kidney disease among patients with type 2 diabetes

AIMS

To estimate the rate of progression of chronic kidney disease (CKD) among patients with type 2 diabetes (T2D) and calculate medical costs associated with progression.

METHODS

We conducted a retrospective cohort study of 25,576 members at Kaiser Permanente who had T2D and at least one serum creatinine measurement in 2005. Using estimated glomerular filtration rate (eGFR), we assigned patients to baseline stages of kidney function (stage 0-2, >60ml/min/1.73m(2), n=21,008; stage 3, 30-59, n=3,885; stage 4, 15-29, n=683). We examined all subsequent eGFRs through 2010 to assess progression of kidney disease. Medical costs at baseline and incremental costs during follow-up were assessed.

RESULTS

Mean age of patients was 60.6years, 51% were men, and mean diabetes duration was 5.3years. At baseline, 17.9% of patients with T2D also had stage 3 or 4 CKD. Incremental adjusted costs that occurred over follow-up (from baseline) was on average $4569, $12,617, and $33,162 per patient per year higher among patients who progressed from baseline stage 0-2, stage 3, and stage 4 CKD, respectively, compared to those who did not progress. Across all stages of CKD, those who progressed to a higher stage of CKD from baseline had follow-up costs that ranged from 2 to 4 times higher than those who did not progress.

CONCLUSIONS

Progression of CKD in T2D drives substantial medical care costs. Interventions designed to minimize decline in progressive kidney function, particularly among patients with stage 3 or 4 CKD, may reduce the economic burden of CKD in T2D.

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.

Diabetes management in the kidney patient

Hyperglycemia management in chronic kidney disease (CKD) patients presents difficult challenges, partly due to the complexity involved in treating these patients, and partly due to lack of data supporting benefits of tight glycemic control. While hyperglycemia is central to the pathogenesis and management of diabetes, hypoglycemia and glucose variability also contribute to outcomes. Multiple agents with different mechanisms of action are now available; some can lower glucose levels without the risk of hypoglycemia. This article reviews metabolic changes present in kidney impairment/failure, current views about glycemic goals, and treatment options for the diabetic patient with CKD.

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.

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.