Study on the changes of Carbonic Anhydrase activity in insulin resistance and the effect of methylglyoxal

Objectives: To determine the serum levels of methylglyoxal (MG) and carbonic anhydrase (CA) activity in known cases of type-II diabetes mellitus with insulin resistance and to compare them with age-sex matched healthy controls. Methods: Eightysix participants were enrolled for the present case-controlled study with ages ranging from 25 to 44 years. The analytes measured were fasting blood glucose, serum insulin, methylglyoxal and carbonic anhydrase assay by standard procedures. Further carbonic anhydrase activities were measured in erythrocytes haemolysate and the effect of methylglyoxal on erythrocyte membrane was studied. The effects of methylglyoxal on erythrocyte carbonic anhydrase activity and insulin reactivity were also measured. Results: The mean serum levels of insulin, fasting blood glucose, carbonic anhydrase activity, methylglyoxal and body mass index (BMI) was significantly higher (p 0.001) in patients compared to the controls. The carbonicanhydrase activity was directly proportional to increasing blood glucose concentration. The haemolysate prepared from the erythrocytes of patients and controls also showed significantly higher carbonic anhydrase activities in patients than the controls. Increased carbonic anhydrase activity in a dose-dependent manner with methylglyoxal was also observed. Conclusion: Insulin resistance is accompanied by increased activity of carbonic anhydrase which is significantlyrelated to increasing methylglyoxal levels.