Glycosylated haemoglobin in uraemia

Glycosylated haemoglobin (GHb) was measured in 71 patients with stable chronic renal failure by the thiobarbituric acid (TBA) reaction and by agar gel electrophoresis. Nineteen patients were diabetic. Of the non-diabetics, 22 were treated conservatively (including 8 children), 15 by maintenance haemodialysis, and 15 by continuous ambulatory peritoneal dialysis. GHb measured by both methods correlated with postprandial blood glucose levels. There was a significant discrepancy between the two methods only in patients with serum urea concentrations greater than 30 mmol/l, mean +/- SD, (6.8 +/- 2.6% vs 8.2 +/- 2.5% for TBA and electrophoresis, respectively). This difference, delta GHb, correlated with serum urea, serum creatinine, and serum bicarbonate, but after logistic regression of results from all 71 patients only serum urea was associated with delta GHb. Lower haemoglobin and GHb and high fetal haemoglobin concentrations in the haemodialysis group suggested increased haemolysis in these patients. Measurement of GHb by the TBA method and by agar gel electrophoresis remain useful indicators of hyperglycaemia in patients with mild, stable chronic renal failure.