ApoB/apoA-I ratio may predict ICAS in stroke patients
MedWire News: The apolipoprotein (apo)B/apoA-I ratio may be a useful marker of intracranial atherosclerotic stenosis (ICAS) in patients with stroke, say Korean researchers who found that a high apoB/apoA-I ratio was significantly associated with ICAS in these patients.
"Several studies have indicated an association of the apoB/apoA-I ratio and the risk of stroke and extracranial carotid stenosis," write Jong-Ho Park (Kwandong University Myongji Hospital, Goyang) and co-authors in the journal Stroke. However, "no prior study has demonstrated an association between the apoB/apoA-I ratio and ICAS."
The team therefore prospectively recruited 464 statin or fibrate naïve ischemic stroke patients (mean age 68.2 years) and categorized them into three groups: intracranial (ICAS; n=236); extracranial (ECAS; n=44), and no cerebral (NCAS; n=184) atherosclerotic stenosis. The apoB/apoA-I ratio was then compared across all groups.
Park et al found that the apoB/apoA-I ratio in the ICAS group was significantly higher than in the ECAS and NCAS groups, at 0.81 versus 0.74 and 0.72, respectively. Furthermore, the ratio was substantially increased in patients with advanced ICAS (defined as having three or more intracranial stenosis), at 0.92.
Multivariate analysis revealed that patients in the highest quartile of the apoB/apoA-I ratio (>0.91 for males and >0.87 for females) had a 2.13-fold increased risk for ICAS when compared with patients in the lowest quartile (<0.60 for males and <0.62 for females).
Moreover, the risk for advanced ICAS had a "dose-response relationship" across apoB/apoA-I quartiles, say the researchers. Indeed, when compared with the first quartile, the risk for advanced ICAS was increased 4.03 fold for patients in the second quartile (0.60-0.73 for males and 0.62-0.73 for females), 4.88 fold for patients in the third quartile (0.74-0.91 for males and 0.74-0.87 for females), and 7.79 fold for patients in the fourth quartile.
A higher low-density lipoprotein cholesterol level failed to indicate an increased risk for ICAS or advanced ICAS, say Park et al.
"These findings concur with recent studies that demonstrated that the apoB/apoA-I ratio is a better predictor of cardiovascular disease than other traditional cholesterol measures," they note.
The current study therefore suggests that the apoB/apoA-I ratio is a "promising biomarker for ICAS and sets forth the rationale for larger studies of diverse populations," concludes the team.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Nikki Withers