Urinary podocalyxin as a novel prognostic biomarker for early diagnosis of diabetic kidney disease and its outcome with telmisartan – a prospective observational study

Background: Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease and end-stage renal disease. Conventional biomarkers, such as the urinary albumin-to-creatinine ratio (UACR), detect functional impairment but may not adequately reflect early podocyte injury. Urinary podocalyxin (uPCX), a podocyte-specific protein, has emerged as a potential early biomarker of glomerular damage. Aims and Objectives: To evaluate uPCX as an early biomarker of diabetic kidney disease and assess its response to telmisartan therapy in patients with type 2 diabetes mellitus (T2DM). Methods: This prospective observational study included 82 patients with T2DM. Baseline assessments included fasting blood sugar (FBS), postprandial blood sugar (PPBS), HbA1c, serum creatinine, UACR, and uPCX. The patients received telmisartan therapy and were reassessed at follow-up. Statistical comparisons between visits were performed using paired tests, with p < 0.05 considered significant. Results: Most participants were aged 61–70 years (35.4%), and 57.3% were male. At baseline, 80.5% of the patients had UACR ≥30 mg/g. Suspicious uPCX levels were observed in 82.9% of patients, while 4.9% had elevated levels. A significant association was observed between UACR and uPCX at baseline (p = 0.010). Following telmisartan therapy, the mean UACR significantly decreased from 101.43 ± 74.06 mg/g to 63.54 ± 37.49 mg/g (p < 0.0001). The mean uPCX levels significantly declined from 1.67 ± 1.23 ng/mL to 0.74 ± 0.34 ng/mL (p < 0.0001). HbA1c levels significantly decreased from 7.77 ± 0.75% to 7.39 ± 1.18% (p < 0.0001). The changes in FBS, PPBS, and serum creatinine levels were not significant. The percentage reduction in UACR and uPCX did not differ significantly across the age or sex groups. Conclusion: uPCX was significantly associated with albuminuria and showed a marked reduction following telmisartan therapy. uPCX may serve as a sensitive biomarker of early podocyte injury and a potential tool for monitoring therapeutic responses in diabetic kidney disease.