Primary glomerular diseases and long-term adverse health outcomes: A nationwide cohort study.

Background: Although glomerular diseases are the third most frequent cause of end-stage kidney disease worldwide, little is known about their long-term outcomes.

Methods: In patients with chronic kidney disease (CKD) stage 3-5 enrolled in the Swedish Renal Registry, we compared risks of hospitalization, kidney replacement therapy (KRT), major cardiovascular events (MACE), and death of the four most frequent primary glomerular diseases (IgA nephropathy [IgAN], focal segmental glomerulosclerosis [FSGS], minimal change disease [MCD], and membranous nephropathy [MN]), and patients with CKD due to the most common non-communicable diseases (control-CKD).

Results: We identified 2396 patients with glomerular disease (97% biopsy-proven, 69% men, 57 years, eGFR 29 mL/min/1.73 m², uACR 88 mg/mmol, 1524 with IgAN, 398 FSGS, 94 MCD, and 380 MN) and 37,697 controls (64% men, 74 years, eGFR 25 mL/min/1.73 m², uACR 23 mg/mmol), mainly with diabetic nephropathy and nephroangiosclerosis. The median follow-up was 6.3 (3.3; 9.9) years. Compared with control-CKD, patients with primary glomerular diseases generally had a lower risk of hospitalization, MACE (adjusted hazard ratios [HRs] ranging from 0.44 to 0.88 depending on the etiology) and death (HRs ranging 0.45-0.76). Patients with IgAN and FSGS had a faster eGFR decline and a higher rate of KRT (HRs 1.26 [95%CI: 1.15-1.37] and 1.34 [1.15-1.57], respectively). Conversely, patients with MN and MCD had a lower KRT rate and slower eGFR decline.

Conclusion: Despite having a lower relative risk of hospitalization, cardiovascular events and mortality, patients with IgAN and FSGS are at higher risk of CKD progression than the most common etiologies of CKD, emphasizing the need for more stringent treatment strategies in these patients.