Predictive role and clinical correlation of copeptin in patients with type 2 diabetes mellitus associated nephropathy approaching end-stage renal disease

Diabetic Kidney Disease (DKD) is the leading cause of End Stage Renal Disease (ESRD). Arginine Vasopressin (AVP) plays pivotal roles in osmoregulation and renal water conservation. As patients with DKD are prone to develop osmotic irregularities, AVP is therefore, a potential pathophysiological target for disruption. Copeptin, a surrogate marker of AVP, is preferred over AVP due to comparatively greater stability and longer half-life. The study is designed to correlate the copeptin levels among subjects with Type 2 Diabetes Mellitus (DM) with worsening renal outcomes. It was a comparative cross-sectional study on 120 subjects with T2DM who were stratified into progressive deteriorating stages of chronic kidney disease (CKD) as per NKF KDOQI guidelines. Different biochemical variables HbA1c, serum BUN, serum creatinine UACR and GFR were done from the affiliated lab. Serum copeptin levels were determined using Copeptin sandwich ELISA technique. Data was analyzed through Statistical Program for Social Sciences (SPSS). Out of the 120 subjects that were recruited for study, 30% of subjects (n = 36) developed severely decreased kidney function with GFR less than 30mL/min/1.73m2. Copeptin levels were seen to be increased with progressive stages of albuminuria (175.8 ± 148.4 pg/ml, 221.2 ± 213.1 pg/ml and 385.3 ± 288.4 pg/ml at UACR stage 1, 2 and 3, respectively) with positive correlation i.e. r = 0.375, p = ≤ 0.001. It was also found to be negatively correlated with declining GFR i.e. from 195.8 ± 174.1 pg/ml at stage 1 CKD to 291.7 ± 268.8 pg/ml at stage 5 CKD (r = -0.409, p = ≤ 0.001). Increase in serum copeptin levels from stage 1 to stage 5 of CKD suggest its predictive role in T2DM associated nephropathy, supporting its potential role as an early biomarker. Early detection may help delay ESRD progression through timely interventions.