Evaluation of iron status in patients with end stage renal disease

Abstract

Background: Anaemia is almost universal in haemodialysis patients. Here, we evaluated the utility and clinical implications of the commonly employed tests in assessing iron status in haemodialysis patients.Methods: In this prospective observational study, we enrolled 100 prevalent haemodialysis patients, and measured transferrin saturation (TSAT) and serum ferritin at enrolment. Patients were categorized to have normal, deficient, overload, or indeterminate status of iron based on KDOQI guidelines. To study anaemia trend, haemoglobin (Hb) level at time of enrolment, as well as levels 3-months before and 3-months after enrolment, were collected. Patient survival outcomes were also obtained till October 2016.Results: Using serum ferritin and TSAT, iron status was determinable in 48% of the patients ie 20%-normal iron status, 25% - iron deficiency, 3% - iron overload. Fifty-two percent of the patients’ iron status was indeterminate by current parameters. In spite of being on standard-of-care treatment in our centre, we observed that mean-Hb level of patients in the indeterminate group showed insignificant increases compared to normal- and deficient-groups. Mean delta-Hb levels over 6-months were 0.80±1.54 g/dl in the indeterminate group, compared to 1.87±1.95 g/dl in the deficient group (P=0.03). In our cohort, 57% had died and 5 lost follow-ups during the study (P=0.30 between groups).Conclusions: Serum ferritin and TSAT accurately categorized the iron status of 48% haemodialysis patients in our study. Divergent serum ferritin and TSAT values, or an iron indeterminate state was prevalent in 52% of our urban dialysis cohort. The indeterminate group had inferior increases in Hb over time with current treatment, showing clinical relevance of this finding. Our data suggests the need for more sensitive indices to accurately assess iron status, and improve anaemia management.