SP435RENAL OUTCOMES OF TYPE 2 DIABETIC PATIENTS WITH NON DIABETIC KIDNEY DISEASES

Abstract

INTRODUCTION AND AIMS: Diabetes is the most common cause of incident endstage renal disease (ESRD) worldwide. However, diabetes patients can have diabetic nephropathy (DN), non-diabetic kidney disease (NDKD) or both. We aimed to evaluate long term renal outcomes of patients with Type 2 diabetes mellitus (T2DM), categorizing them into the three groups. METHODS: We retrospectively analyzed clinical and laboratory data from 74 patients with T2DM who underwent kidney biopsy from 2007 to 2015 in our tertiary hospital. Demographic, clinical, laboratory and biopsy data were retrieved from electronic medical records. Exclusion criteria included incomplete baseline data, patients with Stage 4 and 5 chronic kidney disease (CKD) and loss to follow up within 1 year. Outcomes of interest were progressive CKD as defined by ESRD or doubling of serum creatinine and all-cause mortality. Data was censored at ESRD requiring chronic dialysis or transplant, death and loss to follow-up. RESULTS: The cohort included 74 patients, median age 55.1 (IQR: 48.0, 61.4) years and duration of T2DM 120.0 (48.0, 180.0) months. The predominant ethnic group was Chinese (82.4%). Median baseline serum creatinine at time of biopsy was 110.0 (83.0, 135.8) mmol/L, with median estimated glomerular filtration rate (eGFR) (MDRD) of 58.7 (43.6, 76.7) ml/min/m2 . Majority of the patients (90.5%) received anti-proteinuric therapy prior to biopsy. The most common indication for renal biopsy was presence of nephrotic range proteinuria (78.4%). Median follow up was 42.0 (27.0, 71.3) months. Forty-three (58.1%) patients had isolated DN (Group 1), 4 (5.4%) patients had DN with superimposed NDKD (Group 2) and 27 (36.5%) patients had isolated NDKD (Group 3). The most common NDKD is membranous nephropathy. Two (50%) patients from Group 2 and 16 (59.3%) patients from Group 3 received immunosuppression or disease-specific therapy. On follow-up, 22 (51.2%) patients from Group 1, 4 (100%) patients from Group 2 and 8 (29.6%) patients from Group 3 developed progressive CKD. ESRD occurred in 17 (39.5%) patients from Group 1, at a median interval of 53.0 (38.6, 67.4) months from biopsy, in 2 (50.0%) patients from Group 2 and 4 (14.8%) patients from Group 3. Median time to ESRD was not reached in patients from Group 2 and 3. Nine patients, all from Group 1, had died. Kaplan-Meier analysis showed that the time interval to ESRD was significantly longer in Group 2 patients compared to patients in Group 1 or Group 3 (p=0.016). CONCLUSIONS: T2DM patients with NDKD have better renal outcomes compared to patients with biopsy proven DN. Early renal biopsy should be considered in diabetic patients with biopsy indications to facilitate accurate diagnosis and prompt initiation of disease-specific treatment, in order to achieve better renal survival.