U-shaped relationship between hemoglobin level and severity of ischemic stroke.

Area of Science:

• Neurology
• Hematology

Background:

• Ischemic stroke is a leading cause of disability.
• Hemoglobin levels can influence oxygen delivery and stroke outcomes.
• Early assessment of stroke patients is crucial for prognosis.

Purpose of the Study:

• To investigate the relationship between hemoglobin levels and ischemic stroke severity.
• To determine the association between hemoglobin levels and short-term functional improvement.
• To identify clinical factors associated with hemoglobin levels in stroke patients.

Main Methods:

• Utilized locally weighted scatterplot smoothing (lowess) to analyze stroke severity and hemoglobin.
• Employed linear regression analyses to assess hemoglobin's effect on 7-day National Institutes of Health Stroke Scale (NIHSS) scores.
• Adjusted for confounders including admission NIHSS scores and other clinical factors.

Main Results:

• A U-shaped relationship was observed between admission hemoglobin levels and stroke severity (NIHSS and modified Rankin Scale at day 7).
• Low hemoglobin levels were independently associated with female sex, advanced age, severe stroke, low blood pressure, prior stroke, and non-smoking status.
• Higher NIHSS scores at day 7 were independently associated with lower hemoglobin levels after adjusting for baseline severity.

Conclusions:

• A U-shaped relationship exists between admission hemoglobin levels and ischemic stroke severity.
• No U-shaped relationship was found between hemoglobin levels and functional improvement.
• Low hemoglobin levels are associated with poorer short-term functional outcomes in ischemic stroke patients.