Evaluation of the urinary kidney injury molecule-1 levels in patients with diabetic nephropathy.

PURPOSE Kidney Injury Molecule-1 is a protein that increases in urine following tubular damage. Kidney Injury Molecule-1 levels were correlated with the level of chronic kidney disease secondary to diabetic nephropathy in patients with type 2 Diabetes Mellitus. METHODS Clinical and laboratory findings of 142 patients with diabetic nephropathy and 34 control subjects were analysed. Creatinine and HbA1c levels in blood samples and albumin, creatinine and Kidney Injury Molecule-1 levels in urine samples were assessed. RESULTS Urinary Kidney Injury Molecule-1 levels were significantly increased both in subgroups of diabetic nephropathy (normo-/micro-/macro-albuminuria) and in chronic kidney disease (stage 2-4) compared with controls. Urinary Kidney Injury Molecule-1 levels in stage 2 chronic kidney disease patients were significantly higher than those of the patients with stage 3-4 chronic kidney disease. Urinary Kidney Injury Molecule-1 levels, along with urinary albumin excretion and the duration of diabetes, were found to be independent risk factors associated with low glomerular filtration rates. CONCLUSION Urinary Kidney Injury Molecule-1 levels seems to predict renal injury secondary to diabetic nephropathy in early period independent of albuminuria, because urinary Kidney Injury Molecule-1 was elevated despite normal urinary albumin excretion in the normoalbuminuric subgroup. Urinary Kidney Injury Molecule-1 levels, which are elevated in primarily in stage 2, shows a gradual decrease in patients with chronic kidney disease stages 3 and 4; thus, urinary Kidney Injury Molecule-1 levels may be useful in tracking the progression of kidney disease.