Abstract Body: Objective: High calcium (Ca), low phosphate(P), and Ca-P product (CPP) levels are associated with cardiovascular disease and coronary artery atherosclerosis in patients with chronic kidney disease. However, whether this relationship persists in individuals with carotid artery atherosclerosis of acute ischemic stroke is unknown. We investigated the association of serum Ca, P, and CPP to carotid artery atherosclerotic plaque assessed by high-resolution MR vessel wall imaging in acute ischemic stroke patients.
Methods: A total of 251 ischemic stroke participants with carotid artery atherosclerosis (mean age 68 years old, male 80.1%) were consecutively included in a comprehensive stroke center. Serum Ca, and P were obtained from blood tests after admission, and carotid artery plaque characteristics including plaque burden and vulnerability were evaluated using high-resolution MR vessel wall imaging, then the association between serum Ca, P, CPP, and atherosclerosis plaque characteristics was analyzed in multi-variate linear or logistic regression analysis； Finally, the consistency was also explored in different subgroups.
Results: The mean±SD of serum Ca and P in this population is 2.26±0.11 and 1.16±0.19 individually. Serum P and CPP were associated with carotid artery plaque burden, presented as maximum wall thickness (max WT), wall area, and lipid-rich necrotic core (LRNC), in univariate analysis, with β=-0.205，95% CI (-0.348,-0.061), β=-0.258，95% CI (-0.405,-0.113), OR=0.182, 95% CI (0.034,0.975) for P, and β=-0.203，95% (-0.346,-0.059), β=-0.221，95% CI (-0.366,-0.074), OR=0.466, 95% CI (0.237,0.915) for CPP, respectively. In multivariate regression analysis, after further correction of age, sex in model 1 and cardiovascular risk factors in model 2, P level is associated with wall area independently, β=-0.211, 95% CI (-0.367, -0.052), while CPP is associated with wall area marginally, with β=-0.147, 95%CI (-0.300, 0.008) in model 1, and β=-0.157, 95%(-0.314, 0.004) in model 2. In subgroup analysis, the independent relationship between P and wall area can still be consistent in age＞65 years (β=-0.222, 95%CI [-0.400, -0.011]), male (β=-0.219， 95%CI [-0.446,-0.045], and hypertension (β=-0.314， 95%CI [-0.513, -0.130] subgroups.
Conclusion: Lower serum P was associated with increased carotid artery plaque burden presented with wall area, and this relationship could differ in different age, sex, and hypertension subgroups.