Study On Circadian Rhythm Of Blood Pressure And Relevant Factors Of Progressive Ischemic Stroke

Objective:To explore the possible mechanism and risk factors of progresssive ischemic stroke(PIS),we study the PIS-group and non-progressiving group by comparing the circadian rhythm of blood pressure,characteristics of 24h ambutlatory blood pressure and relevant factors with the aims of giving some guidance to clinical treatment,early prediction and selecting efficiently intervention,then to reduce the incidence of PIS and improve the patients'life qualities.Methods: 113 Patients with stroke oneset less than 24 hours admitted to the department of neurology of our hospital from September 2008 to July 2009 were devided into progressing group(neurological function will deteriorate whether being treated or not during the sixth hour to the first week after the onset of stroke with the NIHSS score being increaced 2 points or more) and non-progressing group(neurological function was in a stable condition whether being treated or not during the sixth hour to the first week after the onset of stroke with the NIHSS score being decreaced, unchanged or increased less than 2 points). 24-hour Ambulatory blood pressure monitoring(ABPM) was conducted for each patient in the first day of admission.The progressing group was carried on ABPM again in the seventh day in a stable condition. The examiners without cardiovascular and cerebrovascular disease to be selected as the control group in the same time. We compared the blood pressure circadian rhythm and characteristics of 24h ambutlatory blood pressure of this three groups and analized its clinical factors in order to investigate the risk factors of PIS.Results:1,There were 41 cases suffered progressive ischemic stroke.The overall incidence was 36.3%; 2. The mean ambulatory blood pressure(except for the mean daytime diastolic blood pressure) of progressing group and non-progressing group were higher than that of the control group(P<0.05). Especially significant in the mean nighttime blood pressure(including systolic and diastolic blood pressure) and all day mean pulse pressure of progressing group. In addition, the rate of the mean 24h blood ambulatory pressure of progressing group within the range of 140~160/85~100mmHg were lower than that of non-progressing group;3. Abnormal circadian rhythm of blood pressure in the progressing group was accounted for 92.7%.The shapes of ambulatory blood pressure(ABP) were primarily non-dipper and reverse-dipper.Abnormal circadian rhythm of blood pressure in the non-progressing group was accounted for 72.2%.The shapes of ABP were primarily non-dipper.Abnormal circadian rhythm of blood pressure in the control group was accounted for 23.3%.There were statistically significant differences among the three groups;4. The difference of blood pressure circadian rhythm which was compared between this two case groups with and without hypertension have no statistically significant(P>0.05);5. The variation of blood pressure circadian rhythm from the first day of admission to the seventh day have no statistically significant(P>0.05);6. univariate analysis showed : There were statistically significant differences(P<0.05) in history of hypertension, history of Diabetes,abnormal blood pressure circadian rhythm, carotid artery atherosclerosis, admission hyperglycemia and no significant differences(P>0.05) in age,sex,history of smoking,history of hyperlipidemia,high plasma fibrinogen concentration,admission high temperature between the progressing group and non-progressing group.7. Put all these significant 5 factors into Logistic regression analysis,result showed that there were three significant factors including history of Diabetes,abnormal blood pressure circadian rhythm,admission hyperglycemia entering into regression model. Among this,PIS was influenced more greatly by abnormal blood pressure circadian rhythm (OR=4.498,95%CI: 1.207~16.763)。Conclusion: 1. Patients with PIS have higher night average ambulatory blood pressure and all-day average Ambulatory pulse pressure levels.Acute ischemic stroke with lower or higher average Ambulatory blood pressure may have a negative impact on the short-term prognosis. 2. The patients with abnormal circadian rhythm of blood pressure have higher risk of PIS,whether there is history of hypertension or not.3. Multiple risk factors and different mechanisms are in relation with episode of PIS. history of Diabetes,abnormal blood pressure circadian rhythm,admission hyperglycemia might be risk factors of PIS. The influence of abnormal blood pressure circadian rhythm is more obvious than that of hypertension.