Association between Glycemic Control and Survival in Patients with Type 2 Diabetes on Peritoneal Dialysis

BACKGROUND: Diabetes is the leading cause of kidney failure globally affecting 40% of people receiving peritoneal dialysis (PD). High quality data on the potential impact of improving glycemic control is needed to inform the current recommendations to individualise HbA1C targets. METHODS: Data from eight countries in the prospective cohort Peritoneal Dialysis Outcomes and Practice Patterns Study (2014-2022) was used to assess the association between baseline HbA1C and all-cause mortality in people with Type 2 diabetes on PD for at least 90 days. Cox proportional hazards model adjusted for potential confounders assessed the relationship in the whole cohort and subgroups. Using inverse probability weighting, an average treatment effect in the treated analysis further investigated potential implications of improved glycemic control. RESULTS: HbA1C was measured at least once in 8,436 patients during a mean follow-up of 16 months. Compared with HbA1C≤8%, HbA1C>8% was associated with higher risk of all-cause mortality in the cohort as a whole (HR 1.18 p=0.02 95%CI 1.03-1.35) and within subgroups; aged <65years (HR 1.28 p=0.01 95% CI1.05-1.56), average albumin >3.0g/dL (HR 1.25 p=0.004 95% CI 1.07-1.46), no pre-existing coronary artery disease (HR 1.24 p=0.008 95% CI 1.06-1.46), haemoglobin <10g/L (HR 1.50 p=0.01 95% CI 1.09-2.07) and PD vintage <1year (HR 1.22 p=0.02 95% CI 1.03-1.45). The projected survival advantage at 3 years for those with HbA1C≤8% compared with >8% was 7% overall, increasing to 12% in younger cohorts (aged <65years). The largest predicted absolute survival advantage of 16% (78% versus 61%) was seen in those aged <65, with a normal serum albumin and no history of coronary artery disease. CONCLUSIONS: Associations between HbA1C and mortality argue for tighter individualised targets for patient subgroups (younger, non-inflamed, without established CAD). Our weighted analysis suggests improved glycemic control (reducing HbA1C to <8%) may result in an absolute reduction in mortality at three years of up to 12% in younger cohorts.