Purpose: This meta-analysis aimed to determine the diagnostic performance of neutrophil gelatinase-associated lipocalin (NGAL) in diabetic nephropathy (DN). Methods: We searched the PubMed, Embase, Wanfang, and China National Knowledge Infrastructure databases for articles published up to 24 April 2019. The meta-analyses were conducted by Stata 11.0, and diagnostic accuracy, sensitivity, specificity, negative and positive likelihood ratios (NLR and PLR), diagnostic odds ratio (DOR), and receiver operating characteristic (ROC) curve data were pooled. Moreover, heterogeneity and small trials bias were evaluated. Results: Six cross-sectional studies were included in the meta-analysis. For the studies of microalbuminuria versus normoalbuminuria, the estimates (95% confidence interval) were as follows: sensitivity, 0.75 (0.51-0.89); specificity, 0.78 (0.70-0.84); PLR, 3.37 (2.49-4.56); NLR, 0.33 (0.16-0.69); DOR, 10.31 (4.05-26.25); and area under the ROC curve (AUC), 0.81 (0.77-0.84). For the studies of microalbuminuria + macroalbuminuria versus normoalbuminuria, the results were as follows: sensitivity, 0.83 (0.66-0.93); specificity, 0.88 (0.67-0.97); PLR, 7.20 (1.97-26.31); NLR, 0.19 (0.08-0.46); DOR, 37.83 (4.84-295.65); AUC, 0.92 (0.90-0.94). Deeks' funnel plot suggested that small trials bias was insignificant in this study. Conclusions: Our findings suggest that NGAL is a potential diagnostic marker for patients with DN and that its diagnostic value for microalbuminuria + macroalbuminuria is superior to that for microalbuminuria. Highlights The first meta-analysis to investigate NGAL diagnostic role in DN. NGAL is valuable for the early diagnosis of DN. The diagnostic value of NGAL in microalbuminuria + macroalbuminuria was much higher.
Keywords: Neutrophil gelatinase-associated lipocalin; diabetic nephropathy; diagnosis; meta-analysis.