Serum fructosamine versus glycosylated hemoglobin as an index of glycemic control, hospitalization, and infection in diabetic hemodialysis patients

Abstract

Diabetes is the most common cause of end-stage renal disease and an important risk factor for morbidity and mortality in dialysis patients. Glycemic control, utilizing serial measurement of glycosylated hemoglobin (HbA1c), is generally recommended to limit end-organ damage, including cardiovascular morbidity and mortality. We, along with others, have previously suggested that HbA1c may not be a reliable measure of glycemic control in dialysis patients, and have therefore explored the use of serum fructosamine (SF) as an alternative marker. The objective of this study was to compare HbA1c levels with SF in monitoring glycemic control and associated morbidity (infection and hospitalization) in diabetic patients in a large urban hemodialysis (HD) center. We enrolled 100 diabetic HD patients and followed them up prospectively for 3 years. Data on demographics, as well as biochemical and clinical data, including hospitalizations and infections, were recorded. The mean age was 63 years. In all 54% were women and the majority were African Americans (72%). As expected, HbA1c and albumin-corrected fructosamine (AlbF) levels were highly correlated and both were significantly associated with serum glucose. AlbF, however, was more highly correlated with mean glucose values when less than 150 mg/dl and was a more useful predictor of morbidity. By univariate logistic regression and by Poisson regression analysis, AlbF, but not HbA1c, was a significant predictor of hospitalization. Additionally, in patients dialyzed by arteriovenous (AV) access (that is, excluding those dialyzed via vascular catheters), AlbF, but not HbA1c, was a significant predictor of infection. In conclusion, AlbF is as reliable a marker as HbA1c for glycemic control in diabetic patients on HD, and may be advantageous for patients with serum glucose in a desirable therapeutic range (<150 mg/dl). In addition, AlbF, but not HbA1c, is associated with morbidity (hospitalizations and infections) in diabetic patients on HD.