Iron deficiency is related to low functional outcome in patients at early rehabilitation after acute stroke

Abstract

Background Iron deficiency (ID) is a common co-morbidity in patients with cardiovascular disease and contributes to impaired functional capacity. The relevance of ID in patients in recovery after acute stroke is not known. We assessed the prevalence of ID and anaemia in relation to functional capacity and to recovery during early rehabilitation after stroke. Methods This observational study enrolled consecutively 746 patients with ischaemic or haemorrhagic stroke at in-patient early rehabilitation (age 68 ± 13 years, female 47%, ischaemic stroke 87%). Functional capacity was assessed before and after rehabilitation using Barthel index (reha-BI), motricity index (MI), trunk control test (TCT), and functional ambulatory category (FAC). ID was defined as ferritin <100 μg/L or as transferrin saturation (TSAT) < 20% if ferritin was 100-< 300 μg/L or if CrP > 5 mg/L. Anaemia was defined as Hb < 12 g/dL (women) and <13 g/dL (men). ResultsThe prevalence of ID and anaemia before rehabilitation were 45% and 46%, respectively, and remained high at discharge (after 27 ± 17 days) at 40% and 48%, respectively. Patients with ID had lower functional capacity compared with patients without ID (reha-BI 20 [±86] vs. 40 [±80], MI 64 [±66] vs. 77 [±41], TCT 61 [±76] vs. 100 [±39], FAC 1 [±4] vs. 4 [±4]; median [IQR], all P < 0.001). ID was related to inflammation (OR 2.68 [95% CI 1.98-3.63], P < 0.001), female sex (OR 2.13 [95% CI 1.59-2.85], P < 0.001), haemorrhagic stroke (OR 1.70 [95% CI 1.11-2.61], P = 0.015), initial treatment on stroke unit , P < 0.001), and anaemia (OR 2.94 [95% CI 2.18-3.96], P < 0.001), while age, BMI, and renal function were not related to ID. In adjusted analysis, ID was associated with low functional capacity in all functional scores: reha-BI (OR 1.66 [95% CI 1.08-2.54], P = 0.02), motricity index (OR 1.94 [95% CI 1.36-2.76], P < 0.001), trunk control test (OR 2.34 [95% CI] 1.64-3.32, P < 0.001) and functional ambulatory category (OR 1.77 [95% CI 1.2-2.63], P < 0.02). Functional capacity improved during rehabilitation regardless of presence of ID, but functional outcome remained significantly lower in patients with ID at the end of rehabilitation (rehab BI and MI, both P < 0.001). Conclusions Iron deficiency and anaemia are common and persistent findings in patients after acute stroke. ID and anaemia are independently related to lower functional capacity after acute stroke and to poor functional outcome after rehabilitation. Regular assessment of iron status may identify patients at risk of low functional recovery.

Association Between Serum Iron Status and Muscle Mass in Adults: Results From NHANES 2015–2018

“…Iron is an essential trace element, which plays a pivotal role in cellular metabolism, survival and proliferation (8). Several studies reported that iron deficient caused anemia, neurocognitive dysfunction, and impaired functional capacity (9,10), whereas iron overload resulted in osteoporosis, neurodegeneration, and cardiovascular diseases (11)(12)(13). In the field of skeletal muscle research, recent studies also demonstrated an association between iron status and muscle disorders in experimental animals (14,15), but the link between serum iron status and muscle mass in human is poorly understood.…”

Causal Association of Iron Status With Functional Outcome After Ischemic Stroke

“…Low TSAT has also been associated with low functional outcomes after IS. 32 In a cohort, which included 35 patients with acute stroke and 44 controls, it was reported that transferrin is associated with a protective role in patients with stroke. 33 In this MR study, we found that TSAT is causally related to poor outcomes after IS, and no relationship for transferrin is identified in the MR analyses.…”

An inflammation-derived and clinical-based model for ischemic stroke recovery

“…The data obtained from our enrolled patients underwent ROC analysis and LASSO-filtered variables to identify valuable predictive indicators, which primarily encompassed the pathophysiology of neuroinflammation, anemia, and antioxidation during the subacute stage of stroke. HGB levels are the gold standard for anemia, commonly and associated with poor outcome function after a stroke 34, 35 . The World Health Organization defines anemia as a hemoglobin level of less than 130 g/L.…”