Role of serum periostin level as profibrotic marker in conjunction with renal resistivity index and shear wave elastography in predicting renal fibrosis in diabetic nephropathy.

BACKGROUND: Renal fibrosis is crucial to be detected early in diabetic kidney disease (DKD). Serum periostin is a biomarker for the early detection of fibrosis in DKD. Moreover, shear wave elastography (PSWE) and the renal resistivity index (RRI) are widely used to evaluate renal fibrosis. We aimed to evaluate periostin's role as an indicator for detecting renal fibrosis in the early stages of DKD, alongside RRI and PSWE. METHODS: Seventy-two type 2 diabetes mellitus patients were subdivided into four groups dependent on glomerular filtration rate (GFR) categories (G1-G4), and eighteen healthy participants were enrolled. Creatinine, HbA1c, eGFR, albumin-creatinine ratio (ACR), and serum periostin were measured. RRI and PSWE values were recorded. RESULTS: Periostin levels increased significantly with DKD progression. Periostin's diagnostic performance of cutoff value, which was 39.92 ng/mL for early detection of DKD, with 97.2% sensitivity and 100% specificity. Both RRI and PSWE values increased significantly with DKD progression. RRI and PSWE cutoff values were 0.5 and 1.52 kPa, respectively, with sensitivity of 83.3% and specificity of 100% for RRI, and for PSWE values demonstrated a sensitivity of 80.6%, and specificity of 100%. Strong positive correlations were observed between periostin levels and both RRI and PSWE values (p < 0.001). CONCLUSIONS: Periostin, RRI and PSWE provide valuable insight into the combined use of biochemical and imaging markers for early detection of renal fibrosis in DKD monitoring of DKD progression. TRIAL REGISTRATION NO: MS-132-2024.