Farvid MS, Djalali M, Siassi F, Farvid SS
Correspondence: Dr Maryam Sadat Farvid, farvidm@yahoo.ca
ABSTRACT
Introduction This study was conducted to investigate the relationship of glomerular and tubular dysfunctions with glycaemic control, lipid, lipoprotein, apolipoproteins and antioxidant status in 72 patients with type 2 diabetes mellitus.
Methods Urine albumin concentration was measured by immunoturbidimetric and urine N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) activities with colorimetric methods. Glycated haemoglobin was measured using affinity chromatography. Erythrocyte glutathione reductase and glutathione peroxidase activities and serum levels of malondialdehyde, lipids, lipoproteins and apolipoproteins were determined in patients with type 2 diabetes mellitus.
Results In univariate regression, urinary albumin excretion, and activities of NAG and AAP were associated with glycaemic control. These glycaemic factors included serum glucose concentrations and glycated haemoglobin. Urinary albumin excretion was also inversely correlated with erythrocyte glutathione peroxidase activity, and positively correlated with erythrocyte glutathione reductase activity. No significant associations were found with serum levels of insulin, lipids, lipoproteins, apolipoproteins, malondialdehyde or blood pressure. In multivariate regression, glycated haemoglobin was the most significant predictor of urinary albumin concentration and with erythrocyte glutathione reductase, whereas only glycated haemoglobin was the independent predictor of tubular dysfunctions. Erythrocyte glutathione peroxidase was not an independent predictor of urinary albumin excretion, after adjusting for glycated haemoglobin, glutathione reductase, systolic blood pressure, diastolic blood pressure and apolipoprotein B.
Conclusion In type 2 diabetes mellitus, both glomerular and tubular dysfunctions are dependent on glycaemic control. Glomerular, but not tubular, dysfunction is also significantly associated with increased glutathione reductase activity.
Keywords: antioxidants, diabetes mellitus, diabetic nephropathy, glomerular dysfunction, tubular dysfunction
Singapore Med J 2007; 48(9): 840–846
