MO933: are Chronic Inflammation and CKD-MBD Risk Factors of Mortality in Hemodialysis Patients?
Authors: Sircuta Alexandru , Bob Flaviu , Chiodan Milena , Maralescu Felix-Mihai , Schiller Adalbert , Schiller Oana-Marina , Petrica Ligia 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Haemodialysis patients are known to be susceptible to a wide range of early and long-term complications such as chronic inflammation, infections, malnutrition, mineral bone disorders (CKD-MBD) and cardiovascular disease that significantly affect the incidence of mortality.The aim of this study is to assess the presence of traditional risk factors for mortality such as diabetes mellitus or cardiovascular disease on one hand and non-traditional risk factors on the other hand (chronic inflammation, CKD-MBD).

METHOD
We conducted a single-centre study that included 63 CKD G5D patients (haemodialysis for 1–5 years) followed up for 48 months. All patients have been assessed at baseline, regarding cardiovascular disease (medical history, echocardiography and ECG), we performed using standard methods blood biochemistry, complete blood count and markers of inflammation (CRP, IL-6) and markers of CKD-MBD (sKlotho, iPTH, serum calcium and serum phosphorus).

RESULTS
After 24 months of follow-up, we found a mortality rate of 22.23%, while after 48 months, the mortality rate was of 50.73%.
Baseline plasma IL-6 levels showed a strong statistically significant correlation with sKlotho (r = 0.57, P = 0.001), but no statistically significant correlation with other elements of CKD-MBD was present (serum calcium, serum phosphorus and iPTH). sKlotho showed a positive correlation with haemodialysis efficiency (eKTV) (r = 0.26, P = 0.04)., Decreased levels of sKlotho at baseline correlated significantly with the presence of signs of ischaemia on ECG (190.3 versus 381.57 pg/mL; P = 0.028). Inflammation markers (IL-6 and CRP) showed no statistically significant correlation with any of the markers of cardiovascular disease (presence of vascular calcifications and of left ventricular hypertrophy).
The level of iPTH at baseline was significantly lower in the group of patients that survived the following 4 years of haemodialysis (428.08 ± 315.39 versus 666.76 ± 484.55 pg/mL, P = 0.029).
In a Cox proportion-hazards regression analysis of predicting factors of mortality, only age and not inflammation markers (IL-6 and CRP) showed a statistically significant correlation with 4-year mortality (P = 0.032). Patients with higher levels of sKlotho showed a decreased risk of mortality, however not statistically significant. We found a higher risk of all-cause mortality after 24 months in patients with diabetes mellitus [OR 6.9, 95% confidence interval (95% CI) 1.6924–28.1469; P = 0.007], and after 48 months in patients with a history of cerebro-vascular disease (OR 21.8571, 95% CI 1.2018–397.5026; P = 0.0371) and with left ventricular hypertrophy (OR 2.7259, 95% CI 0.9596–7.7437; P = 0.0598).

CONCLUSION
In our study, although the inflammation marker IL-6 showed correlations with features of CKD-MBD, it did not lead to an increased mortality, which was influenced rather by traditional risk factors such as age, diabetes mellitus or history of cardiovascular disease, but also by CKD-MBD (iPTH).