Changes of serum and urine neutrophil gelatinase-associated lipocalin in type-2 diabetic patients with nephropathy: one year observational follow-up study

We initiated the present work to explore whether neutrophil gelatinase-associated lipocalin (NGAL) could be used to predict the progression of diabetic nephropathy in type-2 diabetic patients. Seventy-four type-2 diabetic patients were divided into normo-, micro- and macro-albuminuria groups according to their 24 h-urinary albumin excreting rate. Serum and urine NGAL, and other clinical parameters were detected. Patients were followed and measurements were repeated 1 year later. An increased tendency of urine NGAL and a decreased tendency of serum NGAL were detected, from normo-albuminuria group to macro-albuminuria group. Serum NGAL was found to rise after follow-up. Moreover, urine NGAL was found to be correlated positively with cystatin C, urea nitrogen, and serum creatinine (SCr), and inversely with glomerular filtration rate (GFR), while serum NGAL correlated negatively with cystatin C and urea nitrogen, at both baseline and follow-up levels. The results indicate that NGAL correlates closely with renal function. Both serum and urine NGAL are sensitive for predicting the progression of type-2 diabetic nephropathy but they may change differently. Serum NGAL may be more useful in early detection and urine NGAL may be more meaningful in renal function assessment.