engleski

Advanced glycation hemoglobin correlation with diabetic microangiopathy

The consequence of hyperglycaemia is the formation and accumulation of advanced glycation endproducts (AGE) on tissue macromolecules and cells. 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 unavailability of various tissues for analysis. The finding that AGEs are also formed on hemoglobin and that Hb-AGE exists throughout the lifetime of red cells, opens a possibility to assess the 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 diabetes duration of 1-30 yrs and mean age 47 yrs (range 18-79 yrs). Thirty-eight patients had clinically 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 arbitrary units AU/mg Hb. The mean level of Hb-AGE did not significantly differ between diabetics with microangiopathy (4.71?1.2 AU/mg Hb) and patients without complications (4.81?1.1 AU/mg Hb). Hb-AGE did not correlate with age, diabetes duration or severity of retinopathy and/or nephropathy. Similare, there was no correlation of the same parameters in the group of patients without microangiopathy. A correlation (r=0.51, p<0.035) between HbA1c and Hb-AGE level was observed in 66 patients (HbA1c>8%) considered to be in fair-to-poor glycemic control (Hb-AGE=4.76?1.25 U/mg Hb). The amount of hemoglobin linked AGEs did not correlate with the presence or absence of retinopathy and/or nephropathy. It seems that Hb-AGE reflects only the metabolic status, equally in the subjects with and without complications.

diabetes; HbA1c; advanced glycated hemoglobin; microangiopathy

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