Non-Proteinuric Diabetic Nephropathy

Abstract

Diabetic nephropathy patients traditionally show significant macroalbuminuria prior to the development of renal impairment. However, this clinical paradigm has recently been questioned. Epidemiological surveys confirm that chronic kidney disease (CKD) diagnosed by a low glomerular filtration rate (GFR) is more common in diabetic patients than in the non-diabetic population but a low number of patients had levels of proteinuria above that which traditionally defines overt diabetic nephropathy (>500 mg/g). The large number of patients with low levels of proteinuria suggests that the traditional clinical paradigm of overt diabetic nephropathy is changing since it does not seem to be the underlying renal lesion in most of diabetic subjects with CKD.

The large spectrum of renal disease in diabetic patients

“…cohort is small and the diagnostic method was usually not renal biopsy, the results are in line with prior reports [6]. However, recent studies have shown that patients with biopsy-proven DN may be normoalbuminuric [18]. Thus, further studies with larger cohorts and ideally renal biopsy confirmation are necessary to find factors better predicting NDN in type 2 diabetic patients.…”

Tamm Horsfall Glycoprotein and Uromodulin

“…The results suggest that diabetes may be associated with direct tubular toxicity on renal tubular cells. This finding is notable and consistent with recent studies of patients with advanced CKD and diabetes who do not have significant proteinuria/glomerular dysfunction (16).…”

Diabetic nephropathy as the cause of end-stage kidney disease reported on the medical evidence form CMS2728 at a single center

“…In a biopsy study of patients with Type 2 DM and CKD (eGFR <60 mL/min/1.73 m 2 ), normoalbuminuric patients were less likely to have typical glomerular changes of DN, but more likely to have arteriosclerosis and tubule-interstitial fibrosis alone [10]. Normoalbuminuric patients without the glomerular changes of DN may have progressive CKD, but this may be due to hypertension, obesity and intrarenal vascular disease rather than DN nephropathy, and the diagnosis can only be clarified by biopsy [11, 12]. Biopsy series of patients with atypical DN presentations (with or without proteinuria) demonstrated that 35–60% had other causes of glomerular disease, and up to 1/3 had nondiabetic renal disease only, including acute tubular necrosis, hypertensive nephrosclerosis and focal segmental glomerulosclerosis [13, 14].…”

“…The criteria are Grade B ‘moderately strong evidence’ recommendations, especially for patients with Type 1 DM. For Type 2 diabetics, micro- and macroalbuminuria are not as strongly predictive of typical diabetic glomerular changes on biopsy, and are not as strongly associated with retinopathy [8–10, 12, 15, 17]. Although the positive predictive value of retinopathy concurrent with macroalbuminuria is 67–100%, the negative predictive value is quite variable at 20–84% [3].…”