Background: Both chronic kidney disease (CKD) and serum uric acid levels (SUA) are associated to an increased risk of acute ischemic stroke (AIS). This is mediated by several mechanisms including platelet dysfunction, coagulation disorders, endothelial dysfunction, inflammation, and increased risk of atrial fibrillation (AF). Methods: We enrolled 294 consecutive patients admitted for AIS and collected age, sex, lenght of admission, in-hospital mortality and comorbidities (hypertension, diabetes, chronic cardiopathy, AF, dyslipidemia, active cancer, COPD, CKD and dementia). Survival was performed with Kaplan-Meier and Cox regression (forward stepwise method) analysis with SPSS 13.0. Results: Mean age was 82,37 (±9,19) years. Mean length of stay in our internal medicine department was 9,87 (±7,14) days. In-hospital mortality was 10,9%. Patients with SUA >7,0 mg/dl had an increased risk of in-hospital mortality at Kaplan-Meiers regression (p<0,05, at log-rank test). Cox regression model, including all the collected comorbidities, age and sex showed that, in the overall sample, high serum uric acid was independently associated to an increased risk of in-hospital mortality (HR:3,873; 95%CI:1,567-9,573; p<0,05). This effect was even more evident among patients with moderate-to-severe CKD, defined as eVFG<60 ml/min (HR:5,863; 95%CI:1,403-20,501; p<0,05). In the population with normal renal function, we observed that SUA was not associated to a worse outcome (HR: 0,775; 95%CI:0,101-5,980; p=n.s.). Discussion: Increased serum uric acid levels have been associated to increased incidence of cerebrovascular and cardiovascular events in several studies. However, it is not well estabilished whether SUA has a direct effect on the pathogenesis of cardiovascular and cerebrovascular diseases or, merely, a waste product of purine turnover in patients with different alterations of metabolism. Our results suggest that the effects of SUA in the prediction of in-hospital mortality are evident only in patients with CKD which is a well-recongized risk factor for cardiovascular or cerebrovascular diseases. A similar effect can be observed in other high-risk conditions in this population: increased SUA levels do not predict in-hospital death in patients who are not affected by hypertension and diabetes, while in patients with one of these two conditions SUA reaches a statistical significance in predicting the outcome (data not shown). Conclusion: In this population of elderly patients affected by acute ischemic stroke, serum uric acid seem to predict an increased in-hospital mortality only in the subpopulation affected by CKD, while in patients with normal renal function this effect is not significant. A similar effect can be observed in other high-risk conditions, such as hypertension and diabetes. However, larger studies are required to validate these observations.
A study on the relationship between serum uric acid and acute ischemic stroke: the role of chronic kidney disease
Falsetti Lorenzo
Writing – Original Draft Preparation
;
2015
Abstract
Background: Both chronic kidney disease (CKD) and serum uric acid levels (SUA) are associated to an increased risk of acute ischemic stroke (AIS). This is mediated by several mechanisms including platelet dysfunction, coagulation disorders, endothelial dysfunction, inflammation, and increased risk of atrial fibrillation (AF). Methods: We enrolled 294 consecutive patients admitted for AIS and collected age, sex, lenght of admission, in-hospital mortality and comorbidities (hypertension, diabetes, chronic cardiopathy, AF, dyslipidemia, active cancer, COPD, CKD and dementia). Survival was performed with Kaplan-Meier and Cox regression (forward stepwise method) analysis with SPSS 13.0. Results: Mean age was 82,37 (±9,19) years. Mean length of stay in our internal medicine department was 9,87 (±7,14) days. In-hospital mortality was 10,9%. Patients with SUA >7,0 mg/dl had an increased risk of in-hospital mortality at Kaplan-Meiers regression (p<0,05, at log-rank test). Cox regression model, including all the collected comorbidities, age and sex showed that, in the overall sample, high serum uric acid was independently associated to an increased risk of in-hospital mortality (HR:3,873; 95%CI:1,567-9,573; p<0,05). This effect was even more evident among patients with moderate-to-severe CKD, defined as eVFG<60 ml/min (HR:5,863; 95%CI:1,403-20,501; p<0,05). In the population with normal renal function, we observed that SUA was not associated to a worse outcome (HR: 0,775; 95%CI:0,101-5,980; p=n.s.). Discussion: Increased serum uric acid levels have been associated to increased incidence of cerebrovascular and cardiovascular events in several studies. However, it is not well estabilished whether SUA has a direct effect on the pathogenesis of cardiovascular and cerebrovascular diseases or, merely, a waste product of purine turnover in patients with different alterations of metabolism. Our results suggest that the effects of SUA in the prediction of in-hospital mortality are evident only in patients with CKD which is a well-recongized risk factor for cardiovascular or cerebrovascular diseases. A similar effect can be observed in other high-risk conditions in this population: increased SUA levels do not predict in-hospital death in patients who are not affected by hypertension and diabetes, while in patients with one of these two conditions SUA reaches a statistical significance in predicting the outcome (data not shown). Conclusion: In this population of elderly patients affected by acute ischemic stroke, serum uric acid seem to predict an increased in-hospital mortality only in the subpopulation affected by CKD, while in patients with normal renal function this effect is not significant. A similar effect can be observed in other high-risk conditions, such as hypertension and diabetes. However, larger studies are required to validate these observations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
