Carbamylation of hemoglobin in renal failure and clinical aspects.

It was revealed that in renal failure hemoglobin A1 (HbA1) was formed by the binding of substances other than glucose to Hb. It was elucidated that the formation of HbA1 increased in urea-added medium and further increased in media containing urea either stored at 37 degrees C for 1 week or heated at 100 degrees C for five minutes. The increment of HbA1 was proportional to the amount of cyanic acid produced by the treatment of the medium after the addition of urea. We found that there was the best correlation between the HbA1 level and the BUN level of 1 to 2 weeks before. Therefore, it appeared that HbA1 could be an indicator of the state of renal failure of 1 to 2 weeks earlier in patients with renal failure without impaired glucose tolerance, especially in patients on hemodialysis.