Prognostic Significance of Diabetes on Visit-to Visit Ultrafiltration Volume Variability in Chronic Hemodialysis Patients

Background: Patients on chronic hemodialysis (HD) have significantly higher mortality rates than the general population, which is aggravated by diabetes (DM). Suboptimal extracellular fluid management increases the CV risk in HD patients. We aimed to study the effect of ultrafiltration volume variability on CV events and mortality in diabetic and non-diabetic chronic HD patients. Materials and methods: The study included 173 chronic HD patients (median age: 63±13 years; 53% men), of whom 36 (21%) had diabetes. The standard deviation (UVSD) and coefficient of variation (UVCV) of UV variability were calculated and used as indices of UV variability. The effect of ultrafiltration volume (UV) variability was retrospectively analysed over a 24-month period. Results: Patients were categorised by diabetes status and median UVSD (< 568 ml for low and ≥ 568 ml for high) as well as UVCV (< 0.29 for low and ≥ 0.29 for high). Diabetic patients with high UVSD showed significantly higher all-cause mortality (p = 0.028) compared to non-diabetic patients with low UVSD. The diabetes group with high UVCV had also increased mortality rates (p = 0.007) versus non-diabetics. Major adverse cardiovascular events (MACE) were considerably elevated in the high UVSD diabetic group (p = 0.002) compared to low UVSD non-diabetics, while those with high UVCV showed even higher MACE rates (p < 0.001). Cardiovascular mortality did not differ significantly between groups. Logistic regression identified the following factors affecting all-cause mortality: DM (OR: 3.781; p = 0.002), high UVSD (OR: 1.51; p = 0.008), high UVCV (OR: 1.302; p = 0.046) and elevated phosphate levels (OR: 1.107; p = 0.032). For MACE, the key factors were DM (OR: 3.066; p = 0.03), low hemoglobin (OR: 3.026; p = 0.037) and high CRP levels (OR: 2.107; p = 0.002). Conclusion: Chronic HD patients with diabetes and high UVSD or UVCV have increased all-cause mortality and MACE rates. Diabetes and cardiovascular changes caused by increased UF volume variability during HD may contribute to higher CV morbidity and mortality rates in these patients.