engleski

Humoral Methylglyoxal Level Reflects Glycemic Fluctuation

Background/Aim. Methylglyoxal is a physiologic metabolite involved in the post-translational protein modification as precursor of advanced glycation endproducts (AGE), which are related to degenerative alterations of tissues in diabetes. Its physiologic concentration is low ; however, in pathophysiologic conditions it may rise significantly. The aim of the study was to examine a hypothesis that methylglyoxal production is related to glycemic fluctuation. Patients and methods. Methylglyoxal was measured by the HPLC method in 41 diabetic patients, in correlation to daily glucose profile, fasting glucose as well as early (HbA1c) and advanced glycation products. Results. Methylglyoxal was in parallel analyzed in whole blood and plasma samples of the same individual. A significantly higher concentration was measured in plasma than in whole blood samples of both controls (349 55 vs 520 41 nmol/l ; p=0.0002) and diabetic patients (408 130 vs 741 140 nmol/l ; p=0.0000). The 24-h glycemia variability was expressed as M value (a quantitative index of diurnal glucose fluctuation). Elevated methylglyoxal production was observed in patients with M value >20, yielding a highly significant correlation between M value and methylglyoxal level (whole blood: r=0.5, p=0.000 ; plasma: r=0.35, p=0.012). In three cases of morning hypoglycemia, a relationship was observed between fasting plasma glucose and elevated concentration of methylglyoxal. Conclusion. A discrepancy between whole blood and plasma levels of methylglyoxal indicates that glucose-derived triosephosphates are not an exclusive source of methylglyoxal, but that some amounts may also be generated from other metabolic sources, probably from ketone bodies. Significant elevation of methylglyoxal recorded in patients with marked glycemic fluctuation was closely related to M values, an index of diurnal blood glucose deviation from the optimal glycemic control. Glucose fluctuation including hyperglycemic and hypoglycemic episodes through an increased production of toxic aldehydes may be a part of the mechanisms that promote tissue damage in diabetes.

Diabetes ;  -Oxoaldehydes ; Methylglyoxal ; Glycemia fluctuation ; M-value ; Renal function

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