#4664 GENDER DIFFERENCES IN VASCULAR ACCESS FOR INCIDENT HAEMODIALYSIS PATIENTS: A REGISTRY-BASED STUDY
Authors: Roca-Tey Ramon , Comas Jordi , Tort Jaume 
Published: June 2023

Abstract

Background
Gender disparities of some aspects of vascular access (VA) for haemodialysis (HD) have been reported. Aims: To analyze the VA profile of incident HD patients (pts) depending on gender in Catalonia.

Method
Data from the Catalan Renal Registry of 22,859 end-stage kidney disease (ESKD) pts older than 18 years of age starting HD therapy was examined over a 24-year period (1997-2021).

Results
Male (n = 14,921) and female (n = 8038) characteristics were different regarding age (66.2±14.2 vs 67.2±14.4 years), normal functional status (40.2% vs 33.2%), cardiovascular disease (58.3% vs 48%) and obesity rate (body mass index BMI&gt;30 kg/m2: 16.1% vs 25.7%) (for all comparisons, p&lt;0.001). The distribution of the first VA used for starting HD was different in men vs women: fistulae AVF (46.1%, n = 6308 vs 41.3%, n = 3088), graft AVG (0.8%, n = 108 vs 1.7%%, n = 129) and tunnelled catheter (20.4%, n = 2789 vs 23%, n = 1719) (for all comparisons, p&lt;0.001); without differences for non-tunnelled catheter (32.8%, n = 4488 vs 34%, n = 2537) (p = 0.083). Percentage of both men and women starting HD by AVF: it decreased progressively from 1997 (53.4% and 41.8%, respectively) to 2021 (37.3% and 33.2%, respectively) (p&lt;0.001 and p = 0.032, respectively). Percentage of incident men with AVF: it was higher than women in 1997 (53.4% vs 41.8%, p = 0.002) but this difference decreased over time and was no longer significant in 2021 (37.3% vs 33.2%, p = 0.22). Probability of starting HD by AVF: it was independently associated with male gender (odds ratio 1.32 [95% confidence interval: 1.23–1.41], p&lt;0.001) after adjusting for age, primary kidney disease, functional status, BMI, cardiovascular disease and ESKD presentation (multivariate logistic regression analysis). By using a competing risk model, the hazard ratio (HR) for receiving a kidney graft (KG) within five years from starting HD, depending on the first VA used to start HD (AVF vs catheter), was: 1.82 (95% CI: 1.69-1.95, p&lt;0.001) for men and 2.32 (95% CI: 2.11-2.55, p&lt;0.001) for women. In comparison with men that started HD by AVF, the HR of women for receiving a KG within five years from starting HD by AVF was 1.12 (95% CI: 1.04-1.21, p = 0.002). In comparison with women that started HD by catheter, the HR of men for receiving a KG within five years from starting HD by catheter was 1.13 (95% CI: 1.03-1.24, p = 0.007). The HR of death within five years from starting HD, depending on the first VA used to start HD (catheter vs AVF), was: 1.55 (95% CI: 1.47-1.63, p&lt;0.001) for men and 1.95 (95% CI: 1.81-2.11, p&lt;0.001) for women. In comparison with men that started HD by catheter, the HR of death for women within five years from starting HD by catheter was 1.01 (95% CI: 0.95-1.06, p = 0.81). In comparison with women that started HD by AVF, the HR of death for men within five years from starting HD by AVF was 1.26 (95% CI: 1.17-1.36, p&lt;0.001).

Conclusions
1) Although AVF was the main type of VA used for starting HD in both sexes, the percentage of AVF was significantly lower in women at the expense of AVG and tunnelled catheter. 2) Male gender was an independent factor associated with a 32% greater probability of starting HD by AVF than female. 3) Women initiating HD by AVF were more likely to receive a KG over time than men with an AVF. 4) Men and women shared the same probability to die over time after starting HD with a catheter. 5) Men starting HD by AVF were more likely to die over time than women with an AVF. 6) Regardless of gender, initiating HD by catheter was associated with a lower probability of receiving a KG and a higher probability of dying over time compared to AVF.