Endocrine Abstracts

Aims: Glomerular and tubulointerstitial damage plays a role in renal function failure in diabetic patients. While both serum and urine levels of neutrophil gelatinase-associated lipocalin (NGAL) show significantly increased levels in acute renal pathologies, the NGAL increase in active phase indicates a reversible condition in chronic cases. In this study, we determined if urinary excretion of NGAL can be used as an early indicator of diabetic nephropathy, which causes chronic renal damage. We compared urinary NGAL excretions both between type 1 diabetic patients and the healthy control group and between the patients with and without albuminuria within the type 1 diabetic group. The goal of this study was to investigate if NGAL excretion is sensitive enough for clinical use as an early indicator of nephropathy in diabetic patients.

Methods: Fifty-two type 1 diabetic patients and 30 healthy volunteers participated in the study. The diabetic participants were separated into two groups as follows: a normoalbuminuria group consisting of those with an albumin/creatinine ratio less than 30 mg/g and an albuminuria group consisting of those with an albumin/creatinine ratio equal or greater than 30 mg/g. Albumin, creatinine and NGAL were measured in the morning spot urine samples of both the patient and the control group.

Results: The median NGAL level of diabetes patients was 21.1 ng/ml, which was significantly higher than the corresponding value of 11.9 ng/ml in controls. When diabetic patients were compared as those with and without albuminuria, the median urinary NGAL levels of normoalbuminuria and albuminuria were 24.7 and 16.1 ng/ml, respectively, but the difference was not statistically significant.

Conclusion: In type 1 diabetic patients, urinary NGAL excretion was increased but was not significantly correlated with urinary albumin excretion. The greater amount of NGAL excretion among diabetic patients may be due to diabetic nephropathy with possible tubulointerstitial damage pathologies. In this regard, urinary NGAL excretion should not be used as an alternative to microalbuminuria in detecting diabetic nephropathy. There is a need for further studies examining the long-term changes in NGAL excretion levels and renal functions.