The association between perirenal fat volume and nephrolithiasis: A Bloemfontein study

Background: Nephrolithiasis is a well-recognised global health burden associated with significant morbidity. Recent studies have demonstrated a potential association between perirenal fat volume (PFV) and nephrolithiasis, particularly among males, likely related to sex-related differences in visceral fat distribution. However, this association has not yet been investigated within the South African population. We explored the association between PFV and nephrolithiasis by comparing the PFV surrounding a stone-bearing kidney with the PFV surrounding a non-stone-bearing kidney in the same individual in both male and female patients. Methods: A retrospective cross-sectional study was conducted at Universitas Academic Hospital in South Africa on patients diagnosed with unilateral nephrolithiasis. Manual tracing software was applied to non-contrasted computed tomography abdomen studies to calculate the PFV. The PFV difference surrounding normal and pathological kidneys was calculated and described using the Signed-Rank test for paired data. Results: < 0.0001). Conclusion: A significant association between PFV and nephrolithiasis was found. Contribution: This study provides the first South African evidence of a significant association between perirenal fat volume and unilateral nephrolithiasis. It supports the potential use of perirenal fat thickness as a simpler radiological marker for future nephrolithiasis risk assessment and research in South African clinical practice.