Urinary Podocalyxin May Detect Diabetic Nephropathy Early: Study

A new study published in the journal of PLOS One showed that urinary podocalyxin (u-PDX), which increases before overt albuminuria and correlates with the severity of albuminuria and deteriorating eGFR, seems to be a sensitive early indicator of diabetic nephropathy.

Diabetic nephropathy causes chronic kidney damage. The urine albumin to creatinine ratio, which is the conventional biomarker, frequently fails to detect early kidney impairment. Urinary podocalyxin, which indicates underlying podocyte damage, has emerged as a potential and sensitive alternative. To establish its diagnostic effectiveness and allow early treatments, this study compared urine podocalyxin to conventional indicators in a high-risk group of diabetic Bangladeshi adults.

A total of 88 persons were recruited: 29 healthy controls and 59 individuals with type 2 diabetes mellitus (T2DM). Based on uACR, participants with diabetes were divided into three subgroups: normoalbuminuric (n = 29), microalbuminuric (n = 15), and macroalbuminuric (n = 15).

Biochemical indicators and clinical factors were noted. ELISA was used to detect u-PDX concentrations, and Kendall's tau-b and Pearson's correlation coefficients were used to examine relationships with uACR and eGFR. 

u-PDX levels gradually rose among individuals with diabetes in the normo-, micro-, and macroalbuminuric groups. 

Fasting blood glucose, post-glucose plasma glucose, HbA1c, serum creatinine, serum urea, and uACR all showed positive correlations with u-PDX; uACR had the greatest association (r = 0.79, p < 0.001) with serum albumin and eGFR. 

A u-PDX cutoff of 0.80 ng/mL distinguished healthy controls from diabetic patients without albuminuria in pairwise ROC analysis (sensitivity 100.0%, specificity 96.4%); 1.60 ng/mL distinguished diabetic patients without albuminuria from those with microalbuminuria (86.7%, 93.1%); and 5.51 ng/mL distinguished microalbuminuric from macroalbuminuric patients (86.7%, 93.3%). 

The ideal u-PDX threshold for overall discrimination of albuminuria-defined DN in diabetic patients was 2.92 ng/mL.

Overall, urinary podocalyxin may be a useful diagnostic for early detection of diabetic nephropathy. u-PDX concentrations were greater in diabetics and increased gradually with albuminuria, associating favorably with uACR and negatively with eGFR.

While longitudinal research is needed to determine the predictive usefulness of u-PDX, and diagnostic estimations must be externally validated, these findings indicate that measuring podocyte damage with u-PDX might improve early risk stratification and promote prompt management in individuals with T2DM.

Reference:

Hossain, M. S., Dwipi, S. T., Ahmed, N., Murshed, K. M., Aftab, K. A., Al Mahdi, A., Hoque, M. M., Taraq, M. J. H., Hussain, M. Z., & Azad, M. A. K. (2026). Urinary podocalyxin as an early biomarker for diabetic nephropathy. PloS One, 21(7), e0347975. https://doi.org/10.1371/journal.pone.0347975