Anemia as a Predictor of Functional Disability in the Early Stage of Ischemic Stroke in a South Asian Population

BACKGROUND: Reduced hemoglobin concentration has an adverse impact on the ischemic penumbra in patients with ischemic stroke as it causes reduced oxygen delivery to neuronal tissue and predisposes to infarct expansion. There is a paucity of data on the impact of anemia on early functional outcomes. AIMS: To determine the association of anemia on early functional outcomes in a cohort of patients with ischemic stroke. METHODS: This prospective study was conducted among 190 participants with acute ischemic stroke presenting to the National Hospital of Sri Lanka. Data were collected on socio-demographic determinants, clinical presentation, co-morbidities, subtype of stroke, and stroke severity (NIHSS score). Early functional outcomes were assessed by the Modified-Rankin-Score (mRS) and Barthel index (BI) within 48 h of the onset. Anemia was defined as Hb <13 g/dl in males and <12 g/dl in females. RESULTS: The mean age of the population was 62.4 years (SD = 11.8). Most participants (75.8%) were males. Anemia was noted in 56.4% of the total study population (59.0% males; 56.5% females) with a mean Hb of 11.7 g/dl. A total of 20% of patients had moderate to severe stroke severity as defined by an NIHSS of ≥16. Functional status assessment revealed that 67.9% had mRS <3 and 85.8% had BI <75. Furthermore, 85.8% had a composite MRS <3 and/or BI 75. Univariate analysis revealed that anemia was significantly associated with “moderate-severe” functional disability. On logistic regression analyses, this retained significance when the functional disability was assessed by mRS >3 (adjusted OR = 2.36; 95% CI = 1.1–5.1). Receiver operator characteristics (ROC) curves indicated a Hb% of 10.65 g/dl as the cut-off that would predict stroke-related disability assessed by mRS >3 [sensitivity = 86.7%; specificity = 34.2%; and AUC = 0.659 (P < 0.0001)]. CONCLUSIONS: Anemia is an independent determinant of poor functional disability in early acute ischemic stroke.