Neutrophil Gelatinase Associated Lipocalin: Is not an Early Marker Inductor for Diabetic Nephropathy in Qatari Population

Abstract

Background: The WHO Global Report on Diabetes (2016) showed that the number of diabetic patients quadrupled between 1980 and 2016, while causing the death of 1.5 million people. While the global prevalence of diabetes is 9%, the prevalence of diabetes in Qatar is between 17-20%, 45% of which developed diabetic nephropathy. Diabetic Nephropathy is the largest cause of End Stage Renal Disease, and it develops in 20% of diabetic patients. Currently, DN is diagnosed by the detection of microalbumin in urine samples. However, nephropathy can be present even in the absence of albuminuria, and the levels of microalbumin in urine does not correlate with the degree of nephropathic damage. Early detection can prevent total renal failure. Studies have shown that neutrophil gelatinase-associated lipocalin (NGAL) was highly expressed even before the appearance of pathological microalbuminuria in both type 1 and type 2 diabetic patients. The levels of NGAL in urine also correlates with the degree of nephropathic damage. However, currently no information exists about the presence of NGAL in diabetic patients of the Qatari population. Objective: This study aims to determine if there is a relationship between the concentrations of NGAL in urine and kidney function. Methodology: Urine samples of 123 patients were acquired from the Qatar Biobank. Of these, 38 were non-diabetic controls, while 85 were diabetic patients. Type 1 diabetics, pregnant females, smokers, and kidney, liver and cardiovascular disease patients were excluded from the control and case population. Using Enzyme linked immunosorbent assay (ELISA), all samples were tested for the presence of NGAL, and a select few were also tested for microalbumin through an external laboratory. The results obtained were analyzed using Statistical Package for Social Sciences (SPSS) version 24 and Microsoft Excel 2016. Results: No significant difference was found in mean values of uNGAL concentrations in healthy patients, diabetic patients with HbA1c>6% and diabetic patients with HbA1c<6% (p>0.05). However, weak correlation was demonstrated between uNGAL concentrations with serum albumin, HbA1c, serum glucose concentration and albuminuria in diabetic patients with HbA1c>6% (p<0.05). Conclusion: According to the current study uNGAL concentrations does not correlate with any of the kidney function tests, such as glomerular filtration rate, serum creatinine and blood urea nitrogen. So, it cannot be used as a marker to detect diabetic nephropathy in the early stages.