AUTOPSY FINDINGS IN THE KIDNEYS OF DIABETICS A ONE YEAR PROSPECTIVE STUDY

Abstract

Background:
Renal biopsies are not commonly done in patients with Diabetic Nephropathy (DN) unless the presentation is not typical for DN or another disease is suspected. However, it is desirable because renal disease may be due to other causes aside of DN. Research articles describing the morphologic lesions in DN are few.
Objectives:
We set out to define the spectrum of histopathological changes, classify, score and grade the lesions found in kidneys of diabetic patients at autopsy at LUTH and to determine the frequency of these pathologies.
Materials and methods:
All consecutive kidney samples taken at autopsy from persons diagnosed with diabetes within a period of one year at the Department of Anatomic and Molecular Pathology in LUTH were studied. The kidneys were harvested at autopsy and sections were examined using light microscopy to identify the pathological lesions present. The glomerular, tubulointerstitial and vascular lesions characteristic of Diabetic Nephropathy were scored and graded according to the Pathologic classification of Diabetic nephropathy proposed by the Research committee of the Renal Pathology Society. Relevant clinical and biochemical features including Duration of DM, hypertension and Creatinine values were also assessed and correlated with morphologic findings.
Results:
Thirty-eight (38) diabetic cases were identified at autopsy out of 341 autopsies performed within the study period. The age of the patients ranged from 45 to 80 years with a male to female ratio of 1.4:1 and peak occurrence in the 61-70 year age group. Most cases in this study (42.2%) had had diabetes for less than 10 years. Over one-third of the patients died of congestive cardiac failure (36.8%). The overall relative frequency of diabetic nephropathy was 97%. 72.2% of the patients studied showed Class II Diabetic nephropathy. No case with Class IV DN (>50% of the glomeruli showing global sclerosis) was identified. Most cases showed less than 25% of interstitial fibrosis and tubular atrophy. Interstitial inflammation was found in 30.6% while arteriolar hyalinosis and intimal thickening were recorded in 75% and 19.4% of the cases respectively. The relative frequency of hypertension in this study was found to be 81.6%. None of the patients in this study died from complications of end-stage renal disease following diabetic nephropathy. Death occurred from other complications of diabetes such as congestive cardiac failure and septic shock following diabetic foot.

Conclusion:
This study has shown that even though diabetic nephropathy is a common complication of diabetes mellitus in our environment with positive lesions being seen long before uraemia develops, it is a far less common cause of death.