Supplemental Material for: Temporal trends in biopsy-proven kidney diseases: an analysis of 14,447 cases from Northern China, 2012–2023

This retrospective study included all patients who underwent native kidney biopsy and received a definitive histopathological diagnosis at Peking University First Hospital between 2012 and 2023.</p><p dir="ltr">Results: A total of 14,447 cases were analyzed. Primary glomerulonephritis (PGN), secondary glomerulonephritis (SGN), tubulointerstitial disease (TIN), hereditary renal diseases, and other pathologies constituted 64.6%, 28.7%, 4.4%, 1.8%, and 0.4%, respectively.

The proportion of PGN decreased significantly (P < 0.001), while SGN increased (P < 0.001). IgA nephropathy (IgAN) was the predominant PGN subtype (46.1%). Membranous nephropathy (MN) showed a nonsignificant upward tendency before 2017 and declined significantly thereafter.

Among SGN, lupus nephritis (LN) decreased significantly (P < 0.001), whereas diabetic nephropathy (DN) more than doubled and overtook LN as the leading subtype after 2018. Hypertensive nephropathy (HT) nearly tripled, obesity-related glomerulopathy (ORG) more than doubled, and monoclonal immunoglobulin-related renal diseases (MIg-RD) also increased significantly (P = 0.003).</p><p dir="ltr">Conclusion: PGN remained the most common pathological category, with IgAN and MN as the major subtypes.

IgAN exhibited an upward trend, whereas MN showed a nonsignificant upward tendency before 2017 and declined significantly thereafter. LN decreased significantly. In contrast, DN, HT, ORG, and MIg-RD all increased significantly.

DN has overtaken LN as the leading SGN subtype since 2018, reflecting an evolving pattern toward metabolic-related kidney injury.</p>