Sex-specific differences in a large cohort of Brazilian incident dialysis patients over 12 years: A retrospective study

Objective: Sex-specific differences in the epidemiology of chronic kidney disease, such as higher prevalence of women on pre-dialysis and men on chronic dialysis treatment, have been reported worldwide. In this regard, data from non-high-income countries are scarce. We aimed to compare the demographic, clinical, and dialysis characteristics of incident dialysis patients, both men and women, in a large cohort of Brazilian patients over a 12-year period. Methods: This was a multicentric retrospective cohort study coordinated by the Brazilian Society of Nephrology. The study included all adult incident dialysis patients in the Brazilian Dialysis Registry from January 2011 to December 2022. The variables studied encompassed age, skin color, education, CKD etiology, predialysis nephrologist care, dialysis characteristics, and geographic region. Additionally, the sample was analyzed for each of the three 4-year periods over the 12 years of data collection. Results: A total of 24,632 incident dialysis patients were included. Men were 59.1% of the dialysis population, remaining stable over the three 4-year periods. Besides other differences, women started dialysis younger (58.5 +/- 16.2 years vs 59.5 +/- 14.4 years; p < 0.001), had a lower educational level (less than 8 years at school: 54% vs 44%; p < 0.001), received more predialysis nephrologist care (46.2% vs 44.2%; p = 0.04), and had a higher prevalence of peritoneal dialysis (4.4% vs 3.5%; p = 0.03). Conclusion: We consistently observed a higher prevalence of men on dialysis and differences in demographic, clinical, and dialysis characteristics. The underlying reasons for these sex differences still necessitate further clarification.