Associations between diabetes and sex with peritoneal dialysis technique and patient survival: Results from the Australia and New Zealand Dialysis and Transplant Registry cohort study

Background: A differential association between mortality and cause of end-stage kidney disease in patients with type 2 diabetes mellitus (T2DM) has been shown. Sex-specific differences in diabetes-related complications have been described. It is unclear whether sex affects the associations between diabetes and peritoneal dialysis (PD) technique and patient survival. Methods: Using the Australia and New Zealand Dialysis and Transplant Registry, we examined a two-way interaction between sex and diabetes status (no diabetes, T2DM and non-diabetic nephropathy [T2DM + non-DN] and T2DM and diabetic nephropathy [T2DM + DN]) for PD technique failure (including death), all-cause mortality and cause-specific mortality in incident adult PD patients between 1996 and 2016 using adjusted Cox regression. Mediation analysis was conducted to determine whether peritonitis was a mediator in these associations. Results: In 8279 PD patients, those with T2DM + DN had the greatest risks in technique failure, all-cause mortality and cause-specific mortality followed by patients with T2DM + non-DN, then patients without diabetes. Sex modified the association with diabetes status in technique failure (p(interaction) = 0.001) and cardiac mortality (p(interaction) = 0.008). In women with T2DM + DN, the adjusted hazard ratio (HR) for technique failure was 1.45 (1.30-1.62) and was higher than men with T2DM + DN (1.17 [1.08-1.28]; referent: no diabetes). In women with T2DM + DN, the adjusted HR for cardiac mortality was 2.12 (1.73-2.61) and was also higher than men with T2DM + DN (1.66 [1.43-1.95]). Less than 10 % of the effect between diabetes and PD technique failure or mortality was mediated by peritonitis. Conclusions: PD patients with diabetic nephropathy had increased risk of PD technique failure and mortality, with the magnitude of these risks greater in women.