Evidence for the role of lipid peroxides on glycation of hemoglobin and plasma proteins in non-diabetic asthma patients

Abstract

Background Collective evidences reveal that malondialdehyde (MDA), reduced glutathione (GSH) and ascorbic acid can modulate protein glycation. We investigated the concentrations of MDA, GSH, ascorbic acid and protein glycation in asthma patients to delineate the possible association among these parameters. Methods Blood was collected from 18 asthma patients and 16 age and sex matched control subjects. Glycated hemoglobin (HbA 1C), GSH, MDA, vitamin C, fructosamine and glucose were assessed in both groups. The effect of H 2O 2 on glycation of hemoglobin was studied by incubating normal healthy erythrocytes with either 5 or 50 mmol/l glucose concentration. Results Plasma of asthma patients revealed significantly higher concentrations of lipid peroxides and fructosamine concentrations than the matched controls. Glycated hemoglobin concentrations were also found to be significantly increased. Ascorbic acid and GSH concentrations were decreased significantly in the test group when compared with the healthy control group. When the effects of fasting glucose, GSH and ascorbic acid on the concentrations of HbA 1C and fructosamine were refuted by partial correlation analysis, MDA was found to be a significant determinant of HbA1c and fructosamine in patients with asthma. The in vitro model with human erythrocytes showed an enhancement of protein glycation by H 2O 2. Conclusion An increased glycation of proteins was found in asthma patients. These data also support the premise that lipid peroxides per se do have a role to play in glycation of hemoglobin and plasma proteins.