A cohort study on the relationship between cerebrovascular hemodynamic changing and risk of stroke / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the role of cerebrovascular hemodynamic indexes (CVHI) changing in stroke and to provide reference for stroke prevention and risk factor study.</p><p><b>METHODS</b>From 2003 to 2004, participants aged 40 years and above in two communities in Fengxian district were recruited by cluster sampling. Risk factors of stroke and CVHI were investigated and checked during baseline investigation. A total of 10 565 individuals completed the survey and met the inclusion criterion. After baseline investigation, the cohort was followed up for stroke occurrence. Relative risk (RR) of CVHI and common risk factors were estimated by cohort study design.</p><p><b>RESULTS</b>Age of the cohort was (56.2 ± 11.4) years. 4444 (42.1%) were males and 6121 (57.9%) were females. Total follow-up duration was 67 885.7 person-years. A total of 195 stroke cases occurred and incidence density of stroke was 287.2 per 100 000 person-years. Stroke incidence in exposure groups of hypertension, heart disease and alcohol drinking was 3.47% (108/3118), 2.96% (21/710) and 2.50% (47/1882), respectively. The incidence in corresponding non-exposure group was 1.17% (87/7448), 1.77% (174/9855) and 1.70% (148/8683) respectively. There was significant difference between 2 groups (χ(2) value was 62.72, 4.56 and 4.94, respectively, P < 0.05). Stroke incidence in CVHI score < 25, 25 - 49, 50 - 74 and ≥ 75 groups was 9.12% (59/647), 5.68% (44/775), 2.52% (39/1545) and 0.72% (53/7403)(χ(2)trend = 273.57, P < 0.05), respectively. Incidence of stroke in 40 - 49, 50 - 59, 60 - 69, ≥ 70 years age group was 0.22% (8/3565), 1.28% (43/3357), 2.71% (50/1848) and 5.88% (94/1600) (χ(2)trend = 181.48, P < 0.05), respectively. Multiple Cox regression analysis indicated that RR (95%CI) value of hypertension and cigarette smoking was 1.40(1.02 - 1.92) and 1.59(1.19 - 2.12), respectively when comparing with non-exposure group. RR (95%CI) value in CVHI score < 25, 25 - 49 and 50 - 74 points group were 6.15 (4.08 - 9.26), 4.55 (2.98 - 6.96) and 2.68 (1.75 - 4.09), respectively when comparing with the score ≥ 75 points group. RR (95%CI) value in age 50 - 59, 60 - 69 and ≥ 70 years group was 4.61 (2.16 - 9.82), 7.81 (3.67 - 16.60) and 13.49(6.44 - 28.24), respectively when comparing with below 40 years group.</p><p><b>CONCLUSION</b>CVHI score is the strong independent predictive factor and hypertension, cigarette smoking and age are the independent risk factors of stroke.</p>

Study on over-weight, obesity and the exposure to stroke risk factors among 40 year olds and over in a community-based population / 中华流行病学杂志

Objective To describe the distribution of over weight and obesity to discover the level of exposure on risk factors of stroke among people aged 40 and over, in a community-based population.Methods From 2003 to 2004, people aged t≥40 years in a community of Fengxian district in Shanghai were selected by cluster sampling. Out of 11 791 individuals who were selected, 10 565 met the inclusion criteria and responded to the investigation. By face to face interview, a cross-sectional survey was carried out, using a questionnaire for risk factors of stroke. Height, weight and blood pressures were measured and cerebrovascular hemodynamic parameters (CVHP) were checked. Age and gender distribution of over weight and obesity in the population were described. Using 60 year as cut-off point, participants were grouped into three: normal, over weight and obesity by body mass index. Level of stroke risk factor exposure between groups was compared and logistic regression model was used for multiple analyses. Results Proportions of over weight and obesity were 28.5 percent and 4.1 percent in male and 26.3 percent and 4.2 percent in female (P=0.045 ). Systolic and diastolic blood pressure in over weight group were (132.5±19.4)ram Hg and (83.9±10.5)mm Hg(1 mm Hg= 0.133 kPa),which were higher than that in normal weight group and lower than that in obese group (P<0.05). Exposure rate of heart disease,family history of stroke in < 60 year old group and diabetes in ≥60 year group increased along with the increase of weight. Exposure rate of hypertension, abnormality of CVHP score in both age groups were also increased with the increase of weight. Data from multiple logistic regression indicated that hypertension,family history of stroke and heart disease, CVHP score below 75 points, sex and age were independent factors of over weight and obese. Conclusion The prevalence of over weight or obesity in a community-based population among aged 40 years or over was around 30 percent. The overall exposure rate of stroke risk factors were increasing along with the increase of weight, especially for those in the middle age.

Baseline study and analysis on a stroke risk factor-related cohort in Fengxian county of Shanghai / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the exposed level of stroke risk factors in Fengxian county of Shanghai and the relationships between risk factors and stroke.</p><p><b>METHODS</b>Community based populations including 10,565 individuals aged 40 years old and over were cluster sampled from Fengxian county in 2003 or 2004. Status of exposure on common risk factors such as hypertension, cardiovascular disease, diabetes, family history of stroke, cigarette smoking, alcohol intake were gathered while cerebral vascular hemodynamic index (CVHI) was examined, with CVHI score below 75 points as abnormal. During 2003 to 2006, 78 stroke cases occurred. The relationships between risk factors and stroke were analyzed by univariate and Cox proportional hazards regression models.</p><p><b>RESULTS</b>Rates of exposure regarding hypertension, cardiovascular disease, diabetes, family history of stroke, obesity (BMI > or = 28 kg/m2), smoking, drinking and CVHI score abnormal were 21.14%, 6.72%, 1.88%, 5.63%, 4.17%, 34.96%, 17.81% and 29.43%, respectively. Data from Univariate analysis indicated that relative risk (95% CI) of above-mentioned risk factors were 2.76 (1.76-4.32), 2.19 (1.16-4.14), 1.52 (0.38-6.19), 1.58 (0.69-3.62), 1.24 (0.45-3.38), 1.75 (1.12-2.73), 2.10 (1.30-3.39) and 12.72 (7.02-23.06), respectively. Results from Cox proportional hazards regression models analysis showed that cigarette smoking, CVHI score abnormal were screened into equation.</p><p><b>CONCLUSION</b>Among all the risk factors, rate of hypertension was the highest while hypertension, cardiovascular disease, cigarette smoking, alcohol intake and abnomal CVHI score had remarkable etiological correlations to stroke. Abnormal CVHI score, cigarette smoking seemed to be the independent forecasting factors related to stroke.</p>

Baseline study on a stroke-related cohort in the rural community of Shanghai / 中华流行病学杂志

<p><b>OBJECTIVE</b>To present data from a baseline investigation on stroke-related cohort population in rural area of Shanghai.</p><p><b>METHODS</b>A cross-sectional study was carried out in a cluster sampling population aged 40 years and over. General information and data on common risk factors in the population were gathered and cerebral vascular hemodynamic indexes were checked. Hemodynamic score was estimated according to single indexes by unified methods. 5335 persons who had met the inclusion criteria were enlisted in the study. Exposure level of risk factors, prevalence of stroke, and hemodynamic indexes were analyzed and distributional characteristics were described.</p><p><b>RESULTS</b>Exposure rate of hypertension, heart disease, diabetes, family history of hypertension, overweight or obesity in males were 31.74%, 6.09%, 1.16%, 3.22%, 17.64%, 29.68% and were 32.76%, 9.22%, 1.55%, 3.84%, 19.22%, 29.44% in female respectively. Standard prevalence of stroke was 1167.3/100000, which in male was significantly higher than that in female (P < 0.05). The change of cerebral vascular hemodynamic indexes was significantly associated with age. Hemodynamic score in 21.3% of the subjects was below 75 points.</p><p><b>CONCLUSIONS</b>Among population of 40 years old and over in rural areas, hypertension was the principal risk factor regarding the rate of stroke. Prevalence of stroke in males was significantly higher than that in females. Abnormal rate of hemodynamic score was about 20% in this population.</p>

Effectiveness of Nao'an Capsule on stroke prevention among high risk population in Nanhui, Shanghai / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the effectiveness of stroke prevention among high risk population, using Nao'an Capsules.</p><p><b>METHODS</b>Participants were selected from 696,558 residents in Nanhui, using county of Shanghai city. Individuals aged 35 years old and over with at least one risk factor exposure to stroke, received cerebral vascular hemodynamic examination. 18,271 cases meeting the criteria of cerebral vascular hemodynamic indexes accumulative score below 70 points were defined as individuals with high-risk and targets to receive intervention. According to the willingness of the participants, 10,313 cases received Nao'an Capsules for intensive intervention based on general intervention measures compared to 7958 cases only receiving general intervention. After the implementation of intervention, incidence and mortality rates of stroke and the effectiveness of three-year intervention were studied.</p><p><b>RESULTS</b>Incidence of stroke in Nao'an Capsules group was significantly lower than that of the general intervention (P < 0.01) with 53.8% in males and 58.4% in females. The relative risk (RR) in two gender groups were 0.46 (0.33 - 0.64) and 0.39 (0.30 - 0.50) respectively. Multiple logistic regression analysis indicated that the history of hypertension, accumulative score of cerebral vascular hemodynamic indexes, age, gender and Nao'an Capsules intervention were the variables selected into the equation and significantly related to stroke. Among the variables, Nao'an Capsule was the strongest factor with a RR of 0.41.</p><p><b>CONCLUSION</b>Incidence of stroke in Nao'an Capsule intervention group was significantly lower than that in the general intervention group after 3 years of intervention, suggesting that Nao'an Capsule intervention was the strongest factor affecting stroke occurrence in individuals at high-risk.</p>

The relationship between hypertension and cerebral hemodynamic scores of vascular function accumulative / 中华流行病学杂志

<p><b>OBJECTIVE</b>To probe into the relationship between hypertension and hemodynamic score of cerebral vascular accumulative function by though studying the history of hypertension and level of blood pressure.</p><p><b>METHODS</b>The database of blood pressure and cerebral vascular hemodynamic indexes (CVHI) were from baseline data and measurement in a cohort. 18,512 participants who met the included criteria were enlisted in the study. The function scores were estimated using uniform methods according to CVHI. Participants were grouped by age, years of having hypertension and level of blood pressure. Differences of the function score between different groups were compared.</p><p><b>RESULTS</b>The function score in hypertension group was significantly lower than that of normal tension group, which decreased by 13.3 points. Within 5 years of hypertension history, the function score decreased as course of hypertension prolonged. The same trend was found between the score and level of both systolic and diastolic blood pressure. When systolic blood pressure elevated to 140 mmHg or diastolic blood pressure elevated to 95 mmHg, the function score was below 75 points.</p><p><b>CONCLUSION</b>There were significant relationship between decrease of the function scores and medical history, course of hypertension as well as level of blood pressure.</p>

Principal component analysis and integral methods of cerebral vascular hemodynamic parameters / 中华流行病学杂志

<p><b>OBJECTIVE</b>To establish a predicting model for stroke according to cerebral vascular hemodynamic indexes and major risk factors of stroke.</p><p><b>METHODS</b>Participants selected from a stroke cohort with 25,355 population in China. The first step was to carry out principal component analysis using CVHI. Logistic regression with principal component and main risk factors of stroke were then served as independent variables and stroke come on as dependent variables. The predictive model was established according to coefficient of regression and probability of each participant was also estimated. Finally, ROC curve was protracted and predictive efficacy was measured.</p><p><b>RESULTS</b>The accumulative contribution rates of four principal components were 58.1%, 79.4%, 88.4% and 94.6% respectively. Seven variables were being selected into the equation with the first to fourth principal component as history of hypertension, age and sex. Area under ROC curve was 0.855 and optimal cut-off point was probability over 0.05. Sensitivity, specificity and accuracy of stroke prediction were 80.7%, 78.5% and 78.5% respectively.</p><p><b>CONCLUSION</b>The model established by principal component and regression could effectively predict the incidence of stroke coming on.</p>

A cohort study on cerebral vascular hemodynamics accumulative score and risks of stroke / 中华流行病学杂志

<p><b>OBJECTIVE</b>To estimate relative risk (RR) of cerebral vascular hemodynamics indexes (CVHI) accumulative score as well as some other risk factors of stroke.</p><p><b>METHODS</b>A cohort study was carried out in 25 355 participants aged 35 and over in Northeast of China from 1994 to 2001. In the baseline survey, exposure rates of hypertension, diabetes, family history of stroke and hypertension, etc. were collected and CVHI was examined. CVHI accumulative score was synthesized according to contribution of single index. During the 7-year following up, 228 stroke cases were identified and stroke coming on was defined as the endpoint of observation. Uni-variable and multiple variables analysis were carried out for estimating RR of CVHI and other risk factors of stroke.</p><p><b>RESULTS</b>Uni-variables analysis indicated that RR (95% confidence interval, CI) of Hypertension, heart diseases, diabetes, family history of hypertension and stroke, overweight or obesity, alcohol intake, cigarette smoking and CVHI < 75 scores were 3.23 (2.48 - 4.20), 2.53 (1.92 - 3.33), 2.38 (1.55 - 3.64), 1.32 (1.02 - 1.72), 1.82 (1.37 - 2.41), 1.62 (1.25 - 2.11), 1.48 (1.07 - 2.04), 1.76 (1.34 - 2.31) and 7.30 (5.43 - 9.80) respectively. Cox regression analysis showed that CVHI below 75 points, family history of stroke, cigarette smoking, heart disease, hypertension, age and sex were the factors being selected in equation. There was a significant dosage response between the decrease of CVHI score and the increase of stroke risk. RR of stroke reached 12.55 when CVHI below 75 points and history of hypertension appeared in the same individuals.</p><p><b>CONCLUSION</b>Abnormality of CVHI score seemed to be the most important and independent factor among stroke risk factors. Decrease of CVHI score might serve as a marker of high risk and play important role in stroke, especially coexistence with hypertension.</p>

Changes of cerebral vascular hemodynamics from normal population to stroke / 中华流行病学杂志

<p><b>OBJECTIVE</b>To probe into changes of cerebral vascular hemodynamics indexes (CVHI) from normal population to different clinical stage before and after occurring of stroke.</p><p><b>METHODS</b>Participants were selected from 25,355 stroke cohort study population aged 35 years and over in Northeast of China and 55 acute stroke patients were selected from Fuzhou PLA General Hospital. CVHI indexes were checked during baseline investigation or within one week after acute stroke. Participant enlisted in the study were divided into following 5 groups, normal population, high risk population, individuals before stroke, acute stroke patients and convalescence stroke patients. Characteristics of CVHI indexes in different population were analyzed and compared.</p><p><b>RESULTS</b>V(min) of cerebral vascular in previous defined 5 group participants were 11.39 +/- 3.27, 9.66 +/- 3.18, 6.71 +/- 3.30, 4.13 +/- 1.27, 6.78 +/- 3.09, respectively. V(mean) and V(max) were with the same decreasing trends as V(min). However, RV in 5 group participants were 62.35 +/- 21.11, 82.32 +/- 31.16, 122.72 +/- 52.73, 137.46 +/- 49.56 and 115.89 +/- 55.51, respectively. Zcv, WV, DR and CP were also with the same increasing trends as RV. Abnormal rate of CVHI score (< 75 points) from normal population to convalescence stroke patients were 13.3%, 34.7%, 74.1%, 100% and 66.7%, respectively.</p><p><b>CONCLUSION</b>From normal population to clinical stage of stroke, cerebral vascular velocity showed decreasing trends while other indexes, such as RV, Zcv, WV, DR and CP were increasing.</p>

The reference range of cerebrovascular hemodynamics indexes parameters / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the reference range of cerebrovascular hemodynamics indexes (CVHI) in a sampling population.</p><p><b>METHODS</b>Fourteen thousand, four hundred and eighty participants without history of stroke or exposure to risk factors were screened from 26 cities in Northeast China, North China, East China, Northwest China, South China, and Southwest China in the prospective study on stroke intervention. CVHI were checked and 95% confidence intervals were calculated using normal distribution methods, which were grouped by age, sex, area, and check positions.</p><p><b>RESULTS</b>Characteristics of CVHI 95% confidence intervals showed that low limit of carotid blood velocity as V(max), V(min), V(mean) decreased, but upper limit of cerebral RV, Zcv, WV, DR and CP increased with the increase of age. However, Q(mean) and DP did not show significant trends of age difference. Low limit of Q(mean), V(max) and upper limit of RV, DR, CP and DP in males were higher than that in females while upper limit of WV and Zcv in females were higher than that in males. Left carotid low limit of Q(mean), V(mean), V(max), V(min), and upper limit of WV, Zcv and CP were higher than that of the right but upper limit of RV, DR and DP were lower than that of the right. There were no obvious differences between areas.</p><p><b>CONCLUSION</b>Obvious differences of CVHI 95% confidence intervals ranges were found between age groups, sex, and checking positions, respectively, suggesting that the reference ranges of CVHI to be estimated by every subgroup.</p>

Distribution of cerebral vascular hemodynamic indexes / 中华流行病学杂志

<p><b>OBJECTIVE</b>To describe the distribution of cerebral vascular hemodynamic indexes (CVHI).</p><p><b>METHODS</b>A number of 25,355 age 35 and over were selected in the Northeast China by cluster sampling. CVHI were checked during baseline survey and were followed to see the occurrence of stroke. Distribution of CVHI among non-stroke population, individuals prior to the onset of stroke and patients with stroke were described.</p><p><b>RESULTS</b>The CVHI accumulative score, V(mean), V(max) and V(min) were dramatically decreasing, but RV, Zcv, WV and DR were significantly increasing as age increased. V(max), RV and CP were significantly higher in males but WV was lower than that of females. The CVHI accumulative score, V(min) and RV were 95.0, 10.23 and 75.8 in non-stroke population, 51.25, 6.71 and 122.72 pre stroke group, and 55.0, 6.78 and 115.89 in patients with stroke respectively. There were significant differences among three groups after controlling of age and sex (P < 0.01).</p><p><b>CONCLUSION</b>Variance of CVHI was closely related to age, and there appeared a significant abnormal of CVHI before and after stroke.</p>