Urinary angiotensinogen linked to renal arteriolar remodeling in CKD

Renal renin‒angiotensin system (RAS) appears to contribute to renal arteriolar remodeling and future decline in estimated glomerular filtration rate (eGFR), irrespective of potential risk factors, in patients with chronic kidney disease (CKD), a study has found.

This retrospective study sought to explore the yet unknown association between renal RAS and renal arteriolar remodeling and to determine whether altered renal RAS subsequently affected renal function in patients with various CKDs not using RAS inhibitors who underwent renal biopsy.

The authors determined the urinary angiotensinogen (UAGT) levels and wall/lumen ratio (WLR) to assess renal RAS and renal arteriolar remodeling, respectively. Using a linear regression model, they cross-sectionally examined the relationship between ln(UAGT) and ln(WLR).

In addition, the authors longitudinally examined the association between ln(UAGT) and subsequent changes in eGFR per year in the largest subgroup of patients who were diagnosed with IgA nephropathy.

Fifty-four patients (median age 37 years, blood pressure 120/73 mm Hg, eGFR 85 ml/min per 1.73 m², and WLR 0.93) were included in the analysis. A significant and positive association existed between ln(UAGT) and ln(WLR), even after adjusting for classical and nonclassical clinical renal risk factors.

In patients with IgA nephropathy, higher ln(UAGT) correlated with higher ln(WLR). In addition, ln(UAGT) appeared to contribute to a greater decline in eGFR per year over a median period of 8.7 years, even after adjusting for potential confounding factors.