Chronic kidney disease stage 4 and 5: comparison of therapeutic projects before kidney replacement therapy between men and women in Brittany

BACKGROUND: In patients with stage 4 and 5 chronic kidney disease (CKD), the reduction of kidney function prompts decisions regarding kidney replacement therapy (KRT): dialysis, transplantation or an alternative to KRT, ie conservative kidney management. The international literature reports that a majority of patients living with CKD (regardless of stage) are female, whilst more males undergo KRT. The objective of this study was to compare sex differences in terms of clinical trajectories and treatment decision making, taking into account clinico-biological characteristics. METHODS: A registry-based observational cohort study that included adult patients in Brittany, France enrolling CKD stages 4 and 5 between 2019 and 2021. Descriptive statistics were reported using frequencies and percentages, means and standard deviations. Variables included in the multivariate regression models (linear or logistic) were selected based on clinical relevance and statistical significance (P value <0.2 in univariate regression). RESULTS: We included 1623 patients. At inclusion, 1048 patients (64%) had stage 4 CKD, including 627 males. Estimated GFR and age did not differ significantly between males and females. In terms of comorbidities, males had more cardiovascular disease (55% (n = 338)) than females (37% (n = 154), P < 0.001) and were more likely to have KRT planned than females (24% (n = 149) vs 16% (n = 65), P < 0.001). In multivariate logistic regression analysis, female sex was associated with a significantly lower probability of having a KRT plan, as well as a shorter duration of nephrology follow-up (less than one year), older age (>75 years), heart failure, living in a residential care facility or an institution, and having an underlying kidney disease defined as "other", compared with chronic glomerulonephritis. The presence of a stable eGFR explained the majority of the "not discussed" or "undecided" treatment plans for males and females (88% (n = 222) vs 90% (n = 306)). CONCLUSIONS: This study does not support the hypothesis that females with CKD are more likely to choose conservative kidney management than males, but it does suggest females are less likely to have a plan for KRT, which was in turn linked to stable kidney function in both sexes. The data showed no statistical difference in kidney function decline between females and males, however a larger study is needed to confirm this finding. Future research including other markers of kidney function decline could also help test this hypothesis.