| Background:There was no cohort report on the relationship between hypertension subtype andthe incidence of stroke in a large sample of Mongolian population.Objective:To investigate the incidence of stroke and its distribution in Mongolian populationlived in the agricultural and pastoral areas. To investigate the prevalence of hypertensionsubtype and its distribution. To explore the relationship of hypertension subtype and theincidence of stroke, and provide epidemiology evidence for assessment of stroke riskand effective control of of stroke risk factors among population.Subjects and Methods:1. Baseline investigation: A cross-sectional survey was conducted between2002and2003，in which2589participants aged20years and older were recruited from32villages in2adjacent townships located in Kezuohou Banner (county) and NaimanBanner in Inner Mongolia. Written informed consent was obtained for all studyparticipants, and they were administered interview using a standard questionnaire, andthe related physical examination and blood samples collection were conducted bytrained staffs.Data on demographic characteristics, family history of hypertension, smoking andalcohol consumption was obtained. Blood pressure, height, weight, waist circumferenceand hip circumference were measured for all participants according to standard methods.Fasting blood samples were taken in the morning and separated in the field, and thenwere sent to laboratory under low temperature and frozen at-80℃. Triglyceride(TG),total cholesterol(TC), high-density lipoprotein cholesterol(HDL-C), low-densitylipoprotein cholesterol(LDL-C), insulin(INS), C-reactive protein(CRP), intercellularadhesion molecules-1(ICAM-1)and endothelial selectin (E-selectin) were detected for all participants.2. Follow-up survey: In October2008, August2009, August2010and August2012, follow-up surveys were conducted for the2589subjects involved in the baselinestudy. The outcome event was defined as the first occurrence of stroke during the timefrom the baseline to the last follow-up. We interviewed the monitoring data and hospitalmedical records for the subjects who experienced a stroke by household to confirm thestroke events using standard questionnaires.3. Statistical analysis: Epidata3.0software was used to establish a database, andall data was checked after data entry for two times. All statistical analyses wereconducted using SAS9.3and SPSS16.0statistical software. All p-values were based ona2-sided test and a significance level of0.05.Results:1. A total of2589participants, including1064males and1525females, wereincluded in the analysis. There were1621people with normal blood pressure;121people(4.67%) were with isolated systolic hypertension (ISH);272people(10.51%)were with isolated diastolic hypertension (IDH); systolic-diastolic hypertension (SDH)has575people, accounting for22.21%. The prevalence of ISH, IDH, SDH were4.3%,16.4%,24.9%in the male population, respectively, while in the female population were4.9%,6.4%,20.3%, respectively.2. During the10years follow-up,124new stroke cases were occurred among2589participants, of which76cases were ischemic stroke and46cases were hemorrhagicstroke, and2cases were unknown sub-type. The incidence of ischemic stroke in thenormotension, ISH, IDH and SDH groups were1.4%,5.0%,2.2%and7.3%,respectively; while the hemorrhagic stroke were0.5%,1.7%,0.7%and5.9%in thenormotension, ISH, IDH and SDH groups, respectively.3. The incidence density of ischemic stroke in the normotension, ISH, IDH andSDH groups were145/100000,573/100000,244/100000and858/100000person-years,respectively. And the difference among the four groups was statisticallysignificant(P<0.05). The incidence density of hemorrhagic stroke were53/100000,191/100000,81/100000and694/100000, in the normotension, ISH, IDH and SDHgroups, respectively.4. Cox regression analyses for risk of ischemic stroke: the results showed that inunivariate analysis,, the harzard ratios (HRs) and95%confidence interval (CI) of ischemic stroke for participants with ISH, ISH and SDH at baseline were3.939(1.597-9.715),1.660(0.673-4.095) and6.030(3.600-10.100), compared those withnormal blood pressure, respectively. When adjusted for age, sex, smoking, alcoholconsumption, blood glucose, lipids and other factors, the corresponding HRs (95%CI)of ischemic strokewere3.623(1.445-9.086),1.510(0.598-3.816) and5.367(3.049-9.446).5. Cox regression analyses for risk of hemorrhagic stroke: the results showed thatin univariate analysis, HRs (95%CI) of hemorrhagic stroke among ISH, ISH andSDHwere3.605(0.766-16.974),1.522(0.323-7.167) and13.385(6.196-28.915),compared those with normal blood pressure, respectively. When adjusted for age, sex,smoking, alcohol consumption, blood glucose, lipids and other factors, HRs (95%CI)of hemorrhagic stroke were4.501(0.923-21.950),1.596(0.326-7.806), and16.083(6.873-37.635), respectively.6. Multivariable Cox regression analyses for risk of stroke in males and females:the results showed that ISH and SDH were associated with the risk of stroke amongmale population. The HR(95%CI) were4.565(1.823-11.433) and5.923(3.476-10.093),respectively. After multivariate adjustment, the HR(95%CI) were5.001(1.950-12.826)and7.771(4.354-13.871), respectively. In the female population, whether adjusted orunadjusted, only SDH was associated with stroke. The HR(95%CI) were9.483(4.737-18.985) and6.138(2.873-13.111), respectively. The HRs of stroke associatedwith ISH and IDH was not significant among males.7. The Kaplan-Meier procedure was used to draw the cumulative incidence ofstroke in different subtypes of hypertension with follow-up. The results showed thatthe cumulative incidence of stroke among the participants with ISH, IDH and SDHincreased with years of follow-up, but not in those with normal blood pressure. And ineach time period, the participants with SDH had the highest incidence rate, followed bythose with ISH. By Log-rank test, P <0.05.Conclusions:1. The incidence of stroke was high in the study, with a higher incidence in malesthan females in the Mongolian population. Stroke had become an important disease andpublic health issues threaten to the health and lives of local Mongolian.2. The prevalence of SDH was the highest among the prevalence of hypertensionsubtypes in the Mongolian population, followed by ISH. The lowest was the prevalence of IDH.3. Compared to the young population, the older people had higher prevalence ofISH and SDH. However, the prevalence of IDH was the highest in young population.4. ISH and SDH increased the risk of ischemic stroke.5. SDH increased the risk of hemorrhagic stroke. |
PDF Full Text Request