Patterns of renal injury in NIDDM patients with microalbuminuria

Abstract

Microalbuminuria predicts overt nephropathy in non-insulin-dependent diabetic (NIDDM) patients; however, the structural basis for this functional abnormality is unknown. In this study we evaluated renal structure and function in a cohort of 34 unselected microalbuminuric NIDDM patients (26 male/8 female, age: 58 +/- 7 years, known diabetes duration: 11 +/- 6 years, HbA1c: 8.5 +/- 1.6%). Systemic hypertension was present in all but 3. Glomerular filtration rate (GFR) was 101 +/- 27 ml.min-1.1.73 m-2 and albumin excretion rate (AER) 44 (20-199) micrograms/ min. Light microscopic slides were categorized as: C I) normal or near normal renal structure; C II) changes "typical" of diabetic nephropathology in insulin-dependent diabetes (IDDM) (glomerular, tubulo-interstitial and arteriolar changes occurring in parallel); C III) "atypical" patterns of injury, with absent or only mild diabetic glomerular changes associated with disproportionately severe renal structural changes including: important tubulo-interstitial with or without arteriolar hyalinosis with or without global glomerular sclerosis. Ten patients (29.4%) were classified as C I, 10 as C II (29.4%) and 14 as C III (41.2%); none of these patients had any definable non-diabetic renal disease. GFR, AER and blood pressure were similar in the three groups, while HbA1c was higher in C II and C III than in C I patients. Diabetic retinopathy was present in all C II patients (background in 50% and proliferative in 50%). None of the patients in C I and C III had proliferative retinopathy, while background retinopathy was observed in 50% of C I and 57% of C III patients. In summary, microalbuminuric NIDDM patients are structurally heterogeneous with less than one third having "typical" diabetic nephropathology. The presence of both "typical" and "atypical" patterns of renal pathology was associated with worse metabolic control, suggesting that hyperglycaemia may cause different patterns of renal injury in older NIDDM compared to younger IDDM patients.

Atubular Glomeruli and Glomerulotubular Junction Abnormalities in Diabetic Nephropathy

“…On the basis of the observations reported here, it seems reasonable to proceed with more extensive studies of these phenomena in type 1 diabetic patients. Such studies, moreover, may be even more relevant in type 2 diabetes, where there is greater structural heterogeneity (42). Renal pathology in type 2 diabetes is often characterized by tubulointerstitial, glomerulosclerotic, and vascular lesions out of proportion to diabetic glomerulopathy lesions (42), and, in this pathologic setting, it is likely that the phenomena described here may be even more important.…”

Postprandial hyperglycemia and hyperinsulinemia associated with renal arterio-arteriolosclerosis in chronic kidney disease

“…8 Previous studies showed 'atypical' renal pathology in a substantial proportion of patients with type 2 diabetes mellitus: absent or mild glomerular changes with disproportionately severe tubulointerstitial injury and renal arterio-arteriolosclerosis. 32 Renal insufficiency with almost normal urinalysis can be a clinical manifestation of absent or mild glomerular changes with severe tubulointerstitial injury and renal arterio-arteriolosclerosis. 30 Recently, it has been noted that a substantial proportion of type 2 diabetes mellitus patients have renal insufficiency without albuminuria.…”

Association of anaemia in Type 2 DM in patients of Dhiraj General Hospital

“…In the report by Li veachi et al 12 anemia was more prevalent in the diabetic patients with creatinine clearance <60 ml/min. In most studies to date, impaired renal function and albuminuria are the predominant risk factors for anemia in diabetic patients 13 .…”