The Relationship between the Rates of Urinary Albumin Excretion and Glomerular Filtration in Type 1 Diabetes Mellitus Patients

Background/Aim: Albuminuria is recognized as an early marker of diabetic nephropathy, but glomerular hyperfiltration appears prior to its development. The aim of this study was to assess relationship between the rates of urinary albumin excretion and glomerular filtration in different diabetic kidney disease stages of type 1 diabetes mellitus. Methods: According to urinary albumin excretion rate and serum creatinine, seventy patients with type 1 diabetes mellitus were classified into normoalbuminuric (NA), microalbuminuric (MiA), macroalbuminuric (MaA) and chronic renal failure (CRF) group. Their results were compared with those of 23 healthy volunteers. Plasma clearance of Tc-DTPA was used to estimate glomerular filtration rate. Results: Mean clearance value of Tc-DTPA was recorded as increased in NA group (p<0.005), unchanged in MiA group and decreased in both MaA and CRF groups (p<0.0001). The relationship analysis established a significant correlation between albumin excretion rate and glomerular filtration rate only in MaA group (r = −0.588, p=0.008). Conclusion: Related to urinary albumin excretion, glomerular filtration rate alteration appears in the earlier stage and represents a more reliable indicator of renal function impairment in diabetic kidney disease.