Chongke Zhong1, Shoujiang You2, Juping Chen3, Guojie Zhai4, Huaping Du4, Yi Luo5, Xiaofeng Dong6, Yongjun Cao7, Chun-Feng Liu8, Yonghong Zhang9. 1. Department of Epidemiology, School of Public Health and Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, China. 2. Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, Second Affiliated Hospital of Soochow University, Suzhou, China. 3. Department of Neurology, Changshu Hospital of Traditional Chinese Medicine, Suzhou, China. 4. Department of Neurology, Affiliated Wujiang Hospital of Nantong University, Suzhou, China. 5. Department of Neurology, Suzhou Traditional and Western Medicine hospital, Suzhou, China. 6. Department of Neurology, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, China. 7. Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, Second Affiliated Hospital of Soochow University, Suzhou, China; Institutes of Neuroscience, Soochow University, Suzhou, China. 8. Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, Second Affiliated Hospital of Soochow University, Suzhou, China; Institutes of Neuroscience, Soochow University, Suzhou, China. Electronic address: liuchunfeng@suda.edu.cn. 9. Department of Epidemiology, School of Public Health and Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, China. Electronic address: yhzhang@suda.edu.cn.
Abstract
BACKGROUND: The clinical impacts of serum alkaline phosphatase (ALP) and phosphate on early death are not fully understood in patients with acute ischemic stroke. We examined the associations between serum ALP, phosphate, and in-hospital mortality after ischemic stroke. METHODS: Serum ALP and phosphate were measured in 2944 ischemic stroke patients from 22 hospitals in Suzhou City from December 2013 to May 2014. Cox proportional hazard models and restricted cubic splines were used to estimate the relationships between serum ALP and phosphate (both as categorical and continuous variables) and risk of in-hospital mortality. RESULTS: During hospitalization, 111 patients (3.7%) died from all causes. After multivariable adjustment, the hazard ratio (HR) of the highest quartile compared with the lowest quartile of ALP was 2.19 (95% confidence interval [CI], 1.20-4.00) for early death. Restricted cubic spline analysis indicated a significant linear association between ALP and death (P-linearity = .017). A U-shaped association of phosphate with in-hospital mortality was observed (P-nonlinearity = .011). Compared with the third quartile of phosphate (1.08-1.21 mmol/L), HRs of the lowest and highest quartiles for early death were 2.17 (1.15-4.08) and 1.70 (.88-3.30), respectively. Sensitivity analyses further confirmed our findings. CONCLUSIONS: We observed a graded relationship between serum ALP levels and risk of early death in patients with acute ischemic stroke. There was a U-shaped association between phosphate and all-cause mortality with significantly increased risk among patients with lower phosphate levels.
BACKGROUND: The clinical impacts of serum alkaline phosphatase (ALP) and phosphate on early death are not fully understood in patients with acute ischemic stroke. We examined the associations between serum ALP, phosphate, and in-hospital mortality after ischemic stroke. METHODS: Serum ALP and phosphate were measured in 2944 ischemic strokepatients from 22 hospitals in Suzhou City from December 2013 to May 2014. Cox proportional hazard models and restricted cubic splines were used to estimate the relationships between serum ALP and phosphate (both as categorical and continuous variables) and risk of in-hospital mortality. RESULTS: During hospitalization, 111 patients (3.7%) died from all causes. After multivariable adjustment, the hazard ratio (HR) of the highest quartile compared with the lowest quartile of ALP was 2.19 (95% confidence interval [CI], 1.20-4.00) for early death. Restricted cubic spline analysis indicated a significant linear association between ALP and death (P-linearity = .017). A U-shaped association of phosphate with in-hospital mortality was observed (P-nonlinearity = .011). Compared with the third quartile of phosphate (1.08-1.21 mmol/L), HRs of the lowest and highest quartiles for early death were 2.17 (1.15-4.08) and 1.70 (.88-3.30), respectively. Sensitivity analyses further confirmed our findings. CONCLUSIONS: We observed a graded relationship between serum ALP levels and risk of early death in patients with acute ischemic stroke. There was a U-shaped association between phosphate and all-cause mortality with significantly increased risk among patients with lower phosphate levels.