engleski

Advanced glycation hemoglobin correlation with diabetic microangiopathy

The consequence of hyperglycemia is the formation and accumulation of advanced glycation endproducts (AGE) on tissue macromolecules. Experimentally, it is well documented that AGEs are implicated in the pathogenesis of late complications of diabetes. However, the investigation of AGE in vivo in diabetic patients was not feasible due to the inaccessibility of various tissues for analysis. The finding that AGEs are also formed on hemoglobin and that Hb-AGEs exists during the lifetime of the red cells, opens a possibility to assess a parameter of advanced glycation. Therefore, we related Hb-AGE as an index of long-term glycation with the duration of diabetes, patients age and presence of retinopathy and/or nephropathy. Hb-AGE and HbA1c were measured in 100 patients with a mean duration of diabetes of 7 yrs (range 1-30 yrs) and mean age 47 yrs (range 18-79 yrs). Thirty-eight patients had cilinically established retinopathy and/or nephropathy. Hb-AGE was quantified by the competitive ELISA technique using polyclonal anti-AGE-RNase-antibodies to detect AGE immunoreactivities of proteins precipitated in red cell hemolysate. Results are expressed as AGE units/mg Hb. The mean level of Hb-AGE did not significantly differ between diabetics with microangiopathy (9.43+-2.5, range 4.4-14.5) and patients without comlications (9.6+-2.0, range 5.6-13.6). Hb-AGE did not correlate with age (r=0.09), diabetes duration (r=0.05) or severity of retinopathy/nephropathy. Similarly, there was no correlation of the same parameters in the group of patients without microangiopathy. A week correlation (r=0.3) between HbA1c and Hb-AGE level was observed in 65 patients (HbA1c>8%) considered to be in poor glycemia control (Hb-AGE=9.5+-2.3 U/mg Hb). The amount of hemoglobin linked AGEs does not correlate with the presence or absence of retinopathy and7or nephropathy. It seems that Hb-AGE reflects only the metabolic status, both in the subjects with and without complications.

diabetes; advanced glycation; hemoglobin

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