Only diabetes duration, systolic blood pressure, glycosylated hemoglobin, hematuria, and diabetic retinopathy showed statistical significance. Other studies have reported factors to distinguish NDRD from DN only after renal histology is available. However, the results were not uniform, which was likely due to differences in the study populations or selection criteria; thus, a systematic assessment of published findings is needed. Therefore, we conducted a meta-analysis of case-control studies to investigate the potential roles of clinical and laboratory data for discriminating NDRD and DN in patients with type 2 diabetes. No significant difference was found between the two groups of age at the time of biopsy. Diabetes duration of patients with NDRD was shorter than that of patients with DN. But type 2 diabetes may have developed long before these patients were diagnosed. Therefore, the known diabetes duration does not accurately predict the presence or severity of DN. HbA1C was lower in patients with NDRD than those with DN. Hyperglycemia may promote kidney damage through a hemodynamic effect, glycosylation, the polyol pathway, or oxidative stress. One accepted view is that hypertension is an independent risk factor for DN. The mechanisms of hypertension in DM remain complex, such as stimulation of the sympathetic nervous system or activation of the renin-angiotensin system resulting in watersodium retention. Our analyses showed that SBPs and DBPs were both lower in patients with NDRD. In the studies included, study 19 and 25 found that among DN patients, antihypertensive treatment could reduce the rate of decline in GFR and thereby postponed ESRD. But study 21 found no difference in the rate of decline in GFR between patients treated with or without ACEI or ARBs both in DN and NDRD patients. However, anti-hypertensive treatment was initiated and increased at different time points, and a variety of anti-hypertensive drugs were used during followup, all of which may induce a bias in evaluating the effects of these medications. And only one of the included studies mentioned the lipid-lowering treatment. So it is hard to draw a conclusion that blood pressure and lipid profiles were different between NDRD and DN patients. In terms of renal function, our meta-analysis demonstrated that the Scr, Ccr, GFR, and BUN at renal biopsy were not significantly different between patients with DN and NDRD. The impact of NDRD on renal outcomes in type2 diabetic patients has not been well established, and most of the available data were based on the results of previous cross- sectional studies. In a study that AbMole Tolclofos-methyl compared the rate of renal decline in diabetic and nondiabetic patients with chronic kidney disease, when controlling for albuminuria, the mean slope of renal decline was similar in patients with and without diabetes. Higher albuminuria was a predictor of poorer renal outcome, regardless of diabetes condition. Among the studies included in this metaanalysis, five were prospective observational studies.