Spectrum of Non diabetic kidney disease in patients with type 2 diabetes and its clinicopathological correlation.

Diabetes mellitus (DM) is the leading cause of chronic kidney disease worldwide chiefly attributable to diabetic nephropathy (DN). In these patients, non diabetic kidney disease (NDKD) can also occur either alone or superimposed on diabetic nephropathy. This study aimed to identify the prevalence and the etiology of NDKD in our center and also the clinical and laboratory parameters to help distinguish these two entities.

MATERIAL: This was a cross sectional observational study. A total of 47 patients were enrolled in the study during the study period. In all the patients, kidney biopsy was done because of atypical presentations and was examined by light and immunofluorescence microscopy. The clinical & laboratory parameters and the biopsy findings were recorded in a standard proforma.

OBSERVATION: A total of 47 patients (male/female: 34/13 and mean age 52.11±9.36) were included in the study. The chief co morbidity was hypertension which was present in 61.7% of patients. The most common indication of biopsy was nephrotic presentation (38.3%) followed by nephritic illness (25.5%). The prevalence of NDKD in our study cohort was 85.1% of which isolated NDKD was 57.4% and NDKD + DN was 27.7%. The most common histological lesion were membranous glomerulopathy and focal segmental glomerulosclerosis (FSGS) each with a frequency of 15% followed by chronic tubulointerstitial nephritis (CTIN), IgA nephropathy and others. There was significant difference in the median duration of diabetes in these groups and it was around 5 years less in the NDKD group. There was no difference among three groups in term of eGFR, HbA1C and proteinuria.

CONCLUSION: Our study demonstrated a high prevalence of NDKD in the patients with type 2 diabetes. The duration of diabetes was the strongest predictor of NDKD. Kidney biopsy should be undertaken liberally whenever there is strong clinical suspicion especially in the presence of atypical features. The exact histological diagnosis can clarify the further treatment planning as well as the prognosis.