β₂-Microglobulin, Pulse Pressure and Metabolic Alterations in Hemodialysis Patients

Abstract

Background/Aim: Pulse pressure (PP) is a result of arterial stiffness seen in dialysis patients, but may be a consequence of fluid overload. We examined the role of β₂-microglobulin (β₂M) in PP in relation to metabolic alterations in patients on different hemodialysis (HD) modalities. Methods: We studied 76 hemodialyzed patients on regular HD (n = 34), predilution bagged hemodiafiltration (n = 19) and online predilution hemodiafiltration (n = 23). β₂M levels were measured by radioimmunoassay, and the clearance of β₂M was assessed by Kt/V for β₂M. Arterial stiffness was measured as carotid-femoral pulse wave velocity, and PP was derived. Insulin levels were measured using immunoradioassay, and insulin resistance was calculated using homeostasis model assessment insulin resistance (HOMA-IR). Serum bicarbonate levels were measured using a blood gas analyzer, and percent sodium removal was calculated. Results: β₂M levels predict increased PP (p = 0.02) adjusting for age, HD modalities, HD duration, HOMA-IR and percent sodium removal. β₂M was positively associated with HOMA-IR (r = 0.306, p = 0.007). Serum bicarbonate levels and carotid-femoral pulse wave velocity were inversely associated (r = –0.719, p = 0.001). Conclusions: β₂M levels were positively associated with PP, which was influenced mainly by dialysis modality fluid and sodium balance and less by arterial stiffness. β₂M levels were positively associated with insulin resistance. Uremic acidosis may contribute to arterial stiffness.

Treatment with Haemodiafiltration Stabilises Vascular Stiffness (Measured by Aortic Pulse Wave Velocity) Compared to Haemodialysis

“…Our results showed an increase in aortic PWV in patients who remained on haemodialysis or were only recently transferred to haemodiafiltration, whereas there was no overall increase for those established on haemodiafiltration, and are supported by two earlier smaller single-centre studies: one reporting that patients dialysing with haemodiafiltration had lower PWV measurements than those treated by conventional haemodialysis [20] and another noting increased PWV in haemodialysis patients, but with no increase with haemodiafiltration [21]. Although another study observed no differences in carotid-femoral PWV between haemodialysis and haemodiafiltration groups [22], this negative study of just over 100 patients employed multiple observers making a limited number of measurements in a younger dialysis population with fewer diabetics with no correction for heart rate.…”

Association between Urine Creatinine Excretion and Arterial Stiffness in Chronic Kidney Disease: Data from the KNOW-CKD Study

“…It is well known that both muscle wasting and arterial stiffness are prevalent in CKD. Previous studies have shown that PTH, vitamin D, and acidosis are associated with arterial stiffness, as well [28][29][30].…”

The Relationship of Residual Renal Function with Cardiovascular Morbidity in Hemodialysis Patients and the Potential Role of Monocyte Chemoattractant Protein-1

“…Moreover, a faster decline in RRF is noticed in thrice weekly conventional HD compared with PD, which is attributable to common intradialytic hypotension and abrupt volume depletion in HD [7]. However, the use of on-line hemodiafiltration (HDF) with high-flux biocompatible membranes and ultrapure water for dialysate may preserve RRF longer, due partly to less sodium removal compared with conventional HD, resulting in less intradialytic hypotension and improved intradialytic cardiovascular stability [8,9].…”