Non-diabetic renal disease in patients with type 2 diabetes mellitus

Abstract

Objectives: A wide spectrum of non-diabetic renal diseases (NDRD) are reported to occur in patients with type 2 diabetes mellitus. However, the prevalence and nature of NDRD in type 2 diabetics is not widely documented in our country. Therefore, the objectives of this study were to analyse prevalence and spectrum of non-diabetic renal disease in type 2 diabetic patients.

Methods: Two hundred sixty type 2 diabetic with clinical renal diseases were screened for evidence of NDRD, between April 1997 to March 1999. Renal disease other than diabetic nephropathy was found in 32 (12.3%) patients. Their (male 23; female 9) age ranged between 35-72 (mean 54.15+/-10.3) years. The duration of diabetes was < 5 years in 14 (43.7%), between 5-9 years in 8 (25%) and > 10 years in 10 (31.2%) patients.

Results: The presenting clinical syndromes were : chronic renal failure 15 (47%), acute nephritic syndrome 6 (18.7%), nephrotic syndrome 5 (15.6%), acute renal failure 4 (12.5%) and rapidly progressive glomerulonephritis (RPGN) in 2 (6.2%) cases. Overall, incidence of glomerular (46.8%) and tubulo-interstitial lesions (53.2%) were almost equal in type 2 diabetes patients. The spectrum of non-diabetic renal diseases includes : primary isolated glomerulopathy 12 (37.5%); mesangioproliferative GN superimposed on diabetic glomerulosclerosis (DGS) in 3 (9.3%); acute tubulo-interstitial nephropathy (TIN) 4 (12.5%); chronic TIN 10 (31.25%) and three patients had chronic pyelonephritis. Diabetic retinopathy was absent in 22 (69%) cases where 10 (31%) patients had background diabetic retinopathy. None of the patients with non-diabetic glomerular disease had diabetic retinopathy, except two who had DGS in addition to mesangioproliferative GN on renal biopsy. The background diabetic retinopathy was seen in 47% of patients with TIN without clinical evidence of diabetic nephropathy. The recovery of renal function or clinical improvement was observed in 47% of patients with NDRD with institution of appropriate treatment.

Conclusion: The prevalence of NDRD was 12.3% in our type 2 diabetic patients. Both non-diabetic glomerulopathy (47%) and tubulo-interstitial nephropathy (53%) can occur with nearly equal frequency in such patients. It is also gratifying to diagnose and treat NDRD in type 2 diabetics in selected cases.