Associations of Iron Sucrose and Intradialytic Blood Pressure

Rationale & objective: Intradialytic hypotension and intradialytic hypertension are associated with morbidity and mortality in hemodialysis (HD). Many factors can contribute to intra-HD blood pressure (BP) changes, such as drugs with vasoactive properties that can destabilize an already tenuous BP. Intravenous iron sucrose is commonly administered to correct iron deficiency; however, its reported associations with altered hemodynamics have not been consistent.

Study design: Prospective cohort study.

Setting & participants: 950 outpatients receiving maintenance HD.

Exposure: Iron sucrose administered during HD.

Outcome: Intradialytic hypotension, intradialytic hypertension, systolic blood pressure parameters.

Analytical approach: Unadjusted and adjusted Poisson and linear repeated measures regression models.

Results: The mean age of patients included in the study was 53±22 years, 43% were female, and 38% were Black. Mean pre-HD SBP was 152±26 (SD) mm Hg. At baseline, the patients who received higher doses of iron sucrose tended to have diabetes, have longer HD sessions, and have a higher frequency of erythropoiesis-stimulating agent use, compared with those who did not receive iron sucrose. In adjusted models, higher doses of iron sucrose were associated with an 11% lower rate of intradialytic hypotension (incidence rate ratio [IRR] for iron sucrose≥100mg vs 0 mg, 0.89 [95% CI, 0.85-0.94]). In adjusted analyses, the administration of higher doses of iron sucrose during HD was associated with intradialytic hypertension (IRR for iron sucrose≥100mg vs 0 mg, 1.07 [95% CI, 1.04-1.10]).

Limitations: Nonavailability of the precise iron sucrose formulation (volume), laboratory data for each HD session, and outpatient medications. Objective measures of volume status, home medications, and symptom data were not recorded in this study.

Conclusions: We observed an independent association of intravenous iron sucrose administration during HD with a lower risk of intradialytic hypotension and higher risk of intradialytic hypertension. Future studies to better understand the mechanisms underlying these associations are warranted.

Plain-language summary: Intradialytic hypotension and intradialytic hypertension are common among patients on hemodialysis, and they are associated with morbidity and mortality. Although many factors may contribute to these risks, medications administered during hemodialysis play an important role. We studied the significance of the intravenous iron sucrose used to treat iron deficiency and the impact it may have on blood pressure during dialysis. In our study of 950 outpatient hemodialysis patients, we observed that administration of iron sucrose was associated with higher systolic blood pressure (during and after hemodialysis sessions) as well as a lower risk of intradialytic hypotension. We also observed that higher doses of iron sucrose are associated with the development of intradialytic hypertension.