Combined Association of High-Sensitivity C-Reactive Protein and Vitamin D with Short-Term Functional Outcomes in Acute Ischemic Stroke

Background/Objectives: Whether high-sensitivity C-reactive protein (hsCRP) and vitamin D (Vit D) provide complementary prognostic information for acute ischemic stroke is unclear. We examined the separate and joint associations of serum hsCRP and Vit D levels with short-term functional outcomes after acute ischemic stroke. Methods: We retrospectively analyzed 192 patients with brain magnetic resonance imaging-confirmed acute ischemic stroke admitted to a single tertiary center. Stroke severity at admission was graded using the National Institutes of Health Stroke Scale. Physical and cognitive recovery were assessed using the Berg Balance Scale (BBS), Manual Function Test (MFT), Korean Mini-Mental State Examination (K-MMSE), and Korean version of the modified Barthel Index, while disability was graded using the modified Rankin Scale (mRS) at discharge. Results: Among 192 patients stratified into low- (<1.0 mg/L, n = 76), moderate- (1.0–3.0 mg/L, n = 57), and high- (>3.0 mg/L, n = 59) hsCRP groups, serum 25-hydroxyvitamin D fell stepwise as hsCRP rose, and high hsCRP was independently associated with poorer BBS, MFT, K-MMSE, and mRS outcomes. Patients with both high hsCRP and Vit D deficiency (<20 ng/mL) formed the highest-risk group (adjusted odds ratio up to 12.54), with the risk increasing stepwise as the number of adverse markers increased. No significant multiplicative interaction was observed, whereas a significant additive interaction was found only for cognitive impairment. Conclusions: Patients with both elevated hsCRP and Vit D deficiency showed the highest odds of poor short-term outcomes. A simple count of these adverse markers may help identify patients at higher risk after acute ischemic stroke and may help define a subgroup for further evaluation in prospective intervention trials of Vit D supplementation.