Study On The Correlation Between Inter-arm Blood Pressure Difference And Carotid Intima Media Thickness In Patients With Ischemic Stroke

Background: Inter-arm blood pressure difference(IAD)refers to the difference blood pressure between the upper extremity.IAD includes systolic inter-arm blood pressure difference(s IAD)and diastolic inter-arm blood pressure difference(d IAD).IAD is a common finding during routine physical examination,especially in patients with cardiovascular disease risk factors.In primary care,IAD is closely related to a shorter survival time to death or new cardiovascular event of general population.Detection of a difference between arms may identify hypertensive patients at increased risk of cardiovascular events.Such an approach would allow more effective targeting of resources in primary prevention strategies[1].In recent years,with the deepening of the research,the IAD has received increasing attention by clinicians.At present,most of the scholars recognized IAD more than 10 mmHg as cutoff.Studies have found that large IAD is associated with ischemic stroke(IS).Many studies have found that IAD and atherosclerosis are closely related,as atherosclerosis is a systemic disease,suggesting that the correlations between IS and IAD may associated with cerebral arteriosclerosis.Compared to the currently accepted clinical and blood biochemical markers,carotid intima-media thickness(IMT)is a morphological marker of vascular atherosclerosis,reflecting the degree of cerebral atherosclerosis.A meta-analysis of Lorenz et al showed that carotid IMT was a strong predictor of vascular events [2],which can be an independent risk factor in predicting IS and IS recurrence.Objective:To investigated the prevalence of IAD(≥10 mm Hg)and study the relationship between IAD and carotid IMT in IS patients.Explore the relationship between IAD and cerebral atherosclerosis in patients with IS.Methods: A total of 315 patients were collected to this study.Patients after emptying bladder,and rested for 5-10 minutes before the measurements.The blood pressures were measured at both upper arms at the same time using two same type of OMRON(type 7012)automated electro-sphygmomanometer and record the blood pressure.We calculated the BP difference as the absolute value of right-left(|right-left|).Patients were divided into three groups according to sIAD: The Group ONE was s IAD less than 5mmHg;The Group TWO was sIAD greater than or equal to 5mmHg and less than 10 mm Hg;The Group THREE was s IAD greater than or equal to 10 mmHg.Venous blood samples of all patients were collected in the early morning of the next day after fasting to detect total cholesterol(TC),triglyceride(TG),low density lipoprotein cholesterol(LDL),homocysteine(Hcy).The general data of patients were recorded,including age,gender,history of hypertension,history of diabetes,history of smoking,drinking history.All patients underwent carotid artery ultrasonography to detect the IMT,including the carotid artery IMT and carotid bulb IMT,and then took the average of the both sides.compared if there are any difference in age,gender,history of hypertension,diabetes,smoking history,drinking history,blood lipid level,the level of homocysteine,the average carotid artery IMT between the three groups.And correlation analysis between IAD and the average IMT were performed.Results:(1)Of the 315 inpatients,11.11% showed an sIAD≥10mmHg;5.71% showed an d IAD≥10mm Hg;2.54% showed both sIAD and dIAD≥10mmHg.There were 182 males(57.8%)and 133 females(42.2%).The oldest was 92 years old,the youngest was 33 years old,and the average age was 67.59 + 11.93.(2)Single factor analysis of variance(ANOVA)was used to compare blood lipid,Hcy of each group for Measurement data,no significant difference(P > 0.05)was found.A chi-square test was used to compare for qualitative data,there was no significant difference(P > 0.05).ANOVA was conducted to assess the carotid IMT between each group,statistically significant was found each of the three groups(F=7.35 P=0.001),and age is also found Statistically significant of the three groups(F=3.198 P=0.04).(3)Pearson correlation analysis showed that IAD were not related to The gender,age,hypertension,diabetes,TG,TC,LDL,Hcy.There was a positive correlation between sIAD and carotid IMT(r=0.179 P < 0.05);d IAD and carotid IMT were also correlated(r=0.126 P < 0.05).(4)Multiple linear stepwise regression indicated that only sIAD is related to the carotid IMT(B=4.60 P < 0.05),after adjust for age,sex,blood lipid and blood homocysteine level,dIAD was not correlated with carotid IMT(P> 0.05).In addition,there was a weak correlation between s IAD and dIAD(B=0.367,P < 0.01).Conclusion:In IS patients,IAD is correlated with carotid IMT.After adjusting for blood lipid levels and other factors,only s IAD is associated with carotid IMT,suggesting that sIAD is correlated with cerebral atherosclerosis,which may be a marker of atherosclerosis in cerebralvascular disease.