***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective : To investigate the association between midlife systolic blood pressure ( SBP ) and late-life  cognitive decline and brain morphology in a sample of community-dwelling elderly men 68 to 79 years of age . Methods : Subjects are surviving members from the prospect i ve National Heart , Lung , and Blood Institute Twin Study ( intake , 1969 to 1972 ) who , when examined for a fourth time in 1995 through 1997 , underwent brain MRI and repeated assessment of neurobehavioral functioning . Quantification of the MR images determined cerebral volume and total volume of white matter hyperintensities ( WMHIs ) for 392 subjects . Midlife SBP levels measured in 1970 , 1980 , and 1985 were used to classify subjects into low , medium , and high midlife SBP categories . A 10-year change in performance on the Mini-Mental State Examination , Digit Symbol Substitution Test , Benton Visual Retention Test , and Verbal Fluency Test was also calculated for these subjects . For all reported analyses , patients were treated as genetically unrelated individuals . Results : Subjects with high midlife SBP experienced a greater decline in cognitive performance and had larger WMHI volumes at follow-up in late life than did those with low midlife SBP . Decreased brain parenchyma and increased WMHI volumes were associated with decline in neurobehavioral functioning as measured in late life independent of age , education , and baseline levels of cognition . Conclusions : Midlife SBP is a significant predictor of both decline in cognitive function and MR volumetric measures of brain atrophy in late life . Because decline in neurobehavioral functioning was associated with decreased brain volume and increased WMHI volume , we conclude that the long-term impact of elevated SBP on decline in late-life neurobehavioral functioning is likely to be mediated through its chronic , negative effect on structural characteristics of the brain A substantial number of older hypertensive patients have stage 1 isolated systolic hypertension ( systolic blood pressure between 140 and 159 mm Hg and diastolic blood pressure < 90 mm Hg ) , but there are currently no data showing that drug treatment is effective , safe , and /or beneficial . To compare the effects of active treatment compared with placebo on blood pressure , left ventricular hypertrophy , and quality of life among older stage 1 isolated systolic hypertensive patients , a r and omized , double-blind , parallel-group , multicenter clinical trial comparing felodipine ( 2.5 , 5 , or 10 mg once daily ) and matching placebo was performed in 171 patients ( 49 % male , average age 66±7 years , with 49 % white and 30 % Hispanic ) with a baseline blood pressure of 149±7/83±6 mm Hg . During 52 weeks of treatment , patients r and omized to active treatment achieved significantly lower blood pressures ( 137.0±11.7/80.2±7.6 mm Hg for extended-release felodipine versus 147.5±16.0/83.5±9.7 mm Hg for placebo , P < 0.01 for each ) , a reduced incidence of left ventricular hypertrophy ( 7 % for extended release felodipine versus 24 % for placebo , P < 0.04 ) , and improved quality of life ( change in Psychological General Well-Being index , 3.0±6.8 for extended-release felodipine versus −0.8±10.3 for placebo , P < 0.01 ) versus baseline . There were no clinical ly significant differences between treatments in tolerability or adverse effects . Stage 1 isolated systolic hypertension can be effectively and safely treated pharmacologically . Treatment reduced progression to the higher stages of hypertension , reduced the incidence of left ventricular hypertrophy , and improved an overall measure of the quality of life . Larger and longer studies will be needed to document any long-term reduction in cardiovascular event rates associated with treating stage 1 systolic hypertension Although the benefits of antihypertensive treatment in " young " elderly ( under 70 years ) hypertensive patients are well established , the value of treatment in older patients ( 70 - 84 years ) is less clear . The Swedish Trial in Old Patients with Hypertension ( STOP-Hypertension ) was a prospect i ve , r and omised , double-blind , intervention study set up to compare the effects of active antihypertensive therapy ( three beta-blockers and one diuretic ) and placebo on the frequency of fatal and non-fatal stroke and myocardial infa rct ion and other cardiovascular death in hypertensive Swedish men and women aged 70 - 84 years . We recruited 1627 patients at 116 health centres throughout Sweden , who were willing to participate , and who met the entry criteria of three separate recordings during a 1-month placebo run-in period of systolic blood pressure between 180 and 230 mm Hg with a diastolic pressure of at least 90 mm Hg , or a diastolic pressure between 105 and 120 mm Hg irrespective of the systolic pressure . The total duration of the study was 65 months and the average time in the study was 25 months . 812 patients were r and omly allocated active treatment and 815 placebo . The mean difference in supine blood pressure between the active treatment and placebo groups at the last follow-up before an endpoint , death , or study termination was 19.5/8.1 mm Hg . Compared with placebo , active treatment significantly reduced the number of primary endpoints ( 94 vs 58 ; p = 0.0031 ) and stroke morbidity and mortality ( 53 vs 29 ; p = 0.0081 ) . Although we did not set out to study an effect on total mortality , we also noted a significantly reduced number of deaths in the active treatment group ( 63 vs 36 ; p = 0.0079 ) . The benefits of treatment were discernible up to age 84 years . We conclude that antihypertensive treatment in hypertensive men and women aged 70 - 84 confers highly significant and clinical ly relevant reductions in cardiovascular morbidity and mortality as well as in total mortality BACKGROUND Previous studies have reported a higher prevalence of dementia in persons with low blood pressure . OBJECTIVE To examine whether low blood pressure is prospect ively associated with the occurrence of Alzheimer disease and dementia in elderly people . SUBJECTS AND METHODS A community-based , dementia-free cohort ( n = 1270 ) aged 75 to 101 years was longitudinally examined twice within 6 years to detect incident dementia using the Diagnostic and Statistical Manual of Mental Disorders , Revised Third Edition criteria . Cox proportional hazards models were used to analyze blood pressure in association with dementia after adjustment for several potential confounders . RESULTS During the 6-year period , 339 subjects were diagnosed with dementia , including 256 persons with Alzheimer disease . Subjects with very high systolic pressure ( > 180 vs 141 - 180 mm Hg ) had an adjusted relative risk of 1.5 ( 95 % confidence interval [ CI ] , 1.0 - 2.3 ; P = .07 ) for Alzheimer disease , and 1.6 ( 95 % CI , 1.1 - 2.2 ) for dementia . Low systolic pressure ( < /=140 mm Hg ) was not related to incident dementia . In contrast , high diastolic pressure ( > 90 mm Hg ) was not associated with dementia incidence , whereas extremely low diastolic pressure ( < /=65 vs 66 - 90 mm Hg ) produced an adjusted relative risk of 1.7 ( 95 % CI , 1.1 - 2.4 ) for Alzheimer disease and 1.5 ( 95 % CI , 1.0 - 2.1 ; P = .03 ) for dementia . The latter association was pronounced particularly in persons who used antihypertensive drugs . CONCLUSIONS Both low diastolic and high systolic pressure are associated with an increased risk of Alzheimer disease and dementia in this elderly population . The atherosclerotic process may explain the observed associations . In addition , low diastolic pressure may increase dementia risk by affecting cerebral perfusion BACKGROUND Stevioside , a natural glycoside isolated from the plant Stevia rebaudiana Bertoni , has been used as a commercial sweetening agent in Japan and Brazil for > 20 years . Previous animal and human studies have indicated that stevioside has an antihypertensive effect . OBJECTIVES This study was undertaken to investigate the long-term ( 2-year ) efficacy and tolerability of stevioside in patients with mild essential hypertension . Secondary objectives were to determine the effects of stevioside on left ventricular mass index ( LVMI ) and quality of life ( QOL ) . METHODS This was a multicenter , r and omized , double-blind , placebo-controlled trial in Chinese men and women aged between 20 and 75 years with mild essential hypertension ( systolic blood pressure [ SBP ] 140 - 159 mm Hg and diastolic blood pressure [ DBP ] 90 - 99 mm Hg ) . Patients took capsules containing 500 mg stevioside powder or placebo 3 times daily for 2 years . Blood pressure was measured at monthly clinic visits ; patients were also encouraged to monitor blood pressure at home using an automated device . LVMI was determined by 2-dimensional echocardiography at baseline and after 1 and 2 years of treatment . QOL was assessed using the Medical Outcomes Study 36-Item Short-Form Health Survey . Electrocardiographic , laboratory , and QOL parameters were assessed at the beginning of treatment , and at 6 months , 1 year , and 2 years . RESULTS One hundred seventy-four patients ( 87 men , 87 women ) were enrolled in the study , and 168 completed it : 82 ( 42 men , 40 women ; mean [ SD ] age , 52 [ 7 ] years ) in the stevioside group and 86 ( 44 women , 42 men ; mean age , 53 [ 7 ] years ) in the placebo group . After 2 years , the stevioside group had significant decreases in mean ( SD ) SBP and DBP compared with baseline ( SBP , from 150 [ 7.3 ] to 140 [ 6.8 ] mm Hg ; DBP , from 95 [ 4.2 ] to 89 [ 3.2 ] mm Hg ; P < 0.05 ) and compared with placebo ( P < 0.05 ) . Based on patients ' records of self-monitored blood pressure , these effects were noted beginning approximately 1 week after the start of treatment and persisted throughout the study . There were no significant changes in body mass index or blood biochemistry , and the results of laboratory tests were similar in the 2 groups throughout the study . No significant difference in the incidence of adverse effects was noted between groups , and QOL scores were significantly improved overall with stevioside compared with placebo ( P < 0.001 ) . Neither group had a significant change in mean LVMI . However , after 2 years , 6 of 52 patients ( 11.5 % ) in the stevioside group had left ventricular hypertrophy ( LVH ) , compared with 17 of 50 patients ( 34.0 % ) in the placebo group ( P < 0.001 ) . Of those who did not have LVH at baseline , 3 of 46 patients ( 6.5 % ) in the stevioside group had developed LVH after 2 years , compared with 9 of 37 patients ( 24.3 % ) in the placebo group ( P < 0.001 ) . CONCLUSIONS In this 2-year study in Chinese patients with mild hypertension , oral stevioside significantly decreased SBP and DBP compared with placebo . QOL was improved , and no significant adverse effects were noted Objective : To examine the relation of blood pressure ( BP ) to subsequent decline in cognitive function among persons age 65 or over . Methods : All persons age 65 or over in a geographically defined community were invited to participate in a longitudinal study of problems of the elderly .  Interviews were conducted in the participants ’ homes and included two BP measures and four tests of cognitive function . Follow-up interviews 3 and 6 years after baseline repeated the cognitive function tests . These analyses included 4,284 individuals who had baseline and at least one follow-up measure of cognitive function .  The average of z scores of the individual cognitive function tests was used as a global measure of cognitive function . Results : In r and om effects analyses controlling for age , sex , education , and race , there was no significant linear association of either systolic or diastolic BP with 6-year change in global cognitive function score . There was no significant curvilinear association with systolic BP . In tests for a curvilinear association with diastolic BP , there was a suggestion of increased decline among those with low or high diastolic BP ( p = 0.03 for the quadratic diastolic term ) . At baseline , 50 % of participants took some type of medication affecting BP . Conclusion : In this community population where BP treatment was common , there was no association of either high systolic or high diastolic BP at the beginning of the observation interval with 6-year cognitive decline Summary The Syst-Eur Trial is a concerted action of the European Community ’s Medical and Health Research Programme . The trial is carried out in consultation with the World Health Organization , the International Society of Hypertension , the European Society of Hypertension and the World Hypertension League . This article describes the objectives and the protocol of Syst-Eur 
    Output:
    
There is no convincing evidence from the trials identified that blood pressure lowering in late-life prevents the development of dementia or cognitive impairment in hypertensive patients with no apparent prior cerebrovascular disease .