Sex Differences in Glomerular Diseases and Their Long-Term Outcomes

Background: Sex differences in kidney diseases have received limited attention. Research in this area is crucial for developing targeted prevention and intervention strategies that address the unique needs and risk factors of diverse populations. Methods: Retrospective, single-centre study at a reference centre for glomerular diseases. We evaluated the prevalence of glomerular diseases among males and females in terms of clinical characteristics and long-term outcomes. Logistic regression analysis and time-to-event analyses were employed. Results: 232 patients were included; 63% male and 37% female. The most common glomerular disease in males was IgA nephropathy (29%), while females most frequently presented with ANCA-associated glomerulonephritis (19%) and FSGS (19%). Notably, IgG4-related nephritis and membranoproliferative glomerulonephritis were observed only in males. At diagnosis, hypertension was more prevalent in males (71% vs 56%, p=0.035). There were no significant differences in the severity of kidney disease between sexes with the total cohort having a median (interquartile range) eGFR of 51 (25-85) ml/min/1.73m2 and proteinuria 3 (1-6) gr/24h]. During the first year, females had a higher likelihood of infections compared to males (adjusted odds ratio OR 3.0 [95% CI 1.31-7.3], p=0.01), after adjusting for the type of immunosuppressive treatment. Renal recovery at 1st year was similar between the sexes, with males and females showing comparable eGFR increases [8±19 vs 11±21 ml/min/1.73m2, p=0.50] and decreases in proteinuria [57% (0-90) vs 55% (0-83), p=0.35]. Over a median follow-up of 2 years (0.5-4), the 5-year overall survival rate was 90% with no significant difference between males and females (log-rank, p=0.181). In the total cohort, the 5-year renal survival rate was 86%. However, in the subgroup of patients with baseline eGFR<30ml/min/1.73m2, males tended to have worst renal survival (log-rank, p=0.087). Conclusion: This study highlights sex differences in glomerular diseases, particularly in infection rates and hypertension prevalence. Despite these differences, long-term survival rates were similar between sexes. However, males with severe kidney disease at baseline showed a trend towards worse renal survival.