***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: Background —Arterial distensibility measures , generally from pulse-wave velocity ( PWV ) , are widely used with little knowledge of relationships to patient outcome . We tested whether aortic PWV predicts cardiovascular and all-cause mortality in type 2 diabetes and glucose-tolerance – tested ( GTT ) multiethnic population sample s. Methods and Results — Participants were r and omly sample d from ( 1 ) a type 2 diabetes outpatient clinic and ( 2 ) primary care population registers , from which nondiabetic control subjects were given a GTT .  Brachial blood pressures  and Doppler-derived aortic PWV  were measured . Mortality data over 10 years ’ follow-up were obtained . At any level of systolic blood pressure ( SBP ) , aortic PWV was greater in subjects with diabetes than in controls . Mortality risk doubled in subjects with diabetes ( hazard ratio 2.34 , 95 % CI 1.5 to 3.74 ) and in those with glucose intolerance ( 2.12 , 95 % CI 1.11 to 4.0 ) compared with controls . For all groups combined , age , sex , and SBP predicted mortality ; the addition of PWV independently predicted all-cause and cardiovascular mortality ( hazard ratio 1.08 , 95 % CI 1.03 to 1.14 for each 1 m/s increase ) but displaced SBP . Glucose tolerance status and smoking were other independent contributors , with African-Caribbeans experiencing reduced mortality risk ( hazard ratio 0.41 , 95 % CI 0.25 to 0.69 ) . Conclusions —Aortic PWV is a powerful independent predictor of mortality in both diabetes and GTT population sample s. In displacing SBP as a prognostic factor , aortic PWV is probably further along the causal pathway for arterial disease and may represent a useful integrated index of vascular status and hence cardiovascular risk Aortic pulse wave velocity ( PWV ) is a significant and independent predictor of cardiovascular mortality in subjects with essential hypertension and in patients with end-stage renal disease . Its contribution to cardiovascular risk in subjects 70 to 100 years old has never been tested . A cohort of 141 subjects ( mean±SD age , 87.1±6.6 years ) was studied in 3 geriatrics departments in a Paris suburb . Together with sphygmomanometric blood pressure measurements , aortic PWV was measured with a vali date d automatic device . During the 30-month follow-up , 56 patients died ( 27 from cardiovascular events ) . Logistic regressions indicated that age ( P = 0.005 ) and a loss of autonomy ( P = 0.01 ) were the best predictors of overall mortality . For cardiovascular mortality , aortic PWV was the major risk predictor ( P = 0.016 ) . The odds ratio was 1.19 ( 95 % confidence interval , 1.03 to 1.37 ) . Antihypertensive drug treatment and blood pressure , including systolic and pulse pressure , had no additive role . In subjects 70 to 100 years old , aortic PWV is a strong , independent predictor of cardiovascular death , whereas systolic or pulse pressure was not . This prospect i ve result will need to be confirmed in an intervention trial Background —The role of antiretroviral therapy in acceleration of atherosclerosis in patients with human immunodeficiency virus ( HIV ) infection is controversial . We hypothesized that aortic stiffness , an early marker of arteriosclerosis , may be increased in HIV patients treated with protease inhibitors .  Methods and Results —In 32 HIV-infected patients treated with protease inhibitors and 32 age- , sex- , and blood pressure – matched HIV-uninfected control subjects , we obtained aortic pulse wave velocity and central aortic pressure waveform , from which aortic augmentation was calculated . HIV patients had a higher aortic pulse wave velocity ( 7.6±1.1 versus 6.8±1.2 m × s−1 , P=0.015 ) and aortic augmentation ( 6.8±5 versus 4.6±4 mm Hg , P=0.037 ) than control subjects . Age and HIV infection ( both P<0.05 ) independently predicted aortic pulse wave velocity when a consistent number of cardiovascular risk factors was simultaneously controlled for . The cumulative duration of treatment was a predictor of aortic pulse wave velocity , each 5 years of treatment duration being independently related to a 1.35 m × s−1 increase in pulse wave velocity . Conclusions —Aortic stiffness is increased in HIV-positive individuals receiving antiretroviral therapy including a protease inhibitor .  Pulse wave velocity increases with longer exposure to protease inhibitors . We hypothesize that arteriosclerosis is a side effect of antiretroviral treatment including a protease inhibitor Recent studies have suggested that a high pulse wave velocity ( PWV ) , a measure of aortic stiffness , may be a stronger risk factor for cardiovascular disease ( CVD ) than a high blood pressure ( BP ) . The relation between insulin , believed to play an important role in the development and clinical course of high BP , and PWV is not yet clear . Therefore , we decided to examine the relationship between insulin and PWV in a large population -based study . The study population consisted of a r and om sample of 1213 women and 1207 men ( age range , 41–72 years ) without a history of myocardial infa rct ion or stroke .  Fasting insulin was determined together with conventional risk factors for CVD . PWV was recorded transcutaneously by a mechanical electrical principle with one transducer positioned over the left common carotid artery , and another over the left femoral artery . In univariate analysis , insulin was highly significantly related to PWV ( st and ardized regression coefficient : 0.0669±0.0051 ; P<0.001 ) . In multivariate analysis , controlling for all well-established predictors of PWV , such as age , systolic BP or mean BP and pulse pressure , sex , and heart rate , as well as controlling for conventional risk factors for CVD and use of BP-lowering drugs , the level of insulin remained a significant predictor of PWV ( st and ardized regression coefficient : 0.0122±0.0048 ; P=0.012 ) . In conclusion , the present study found that a higher insulin level  was related to a higher PWV . This indicates that hyperinsulinaemia may affect BP and risk of CVD by increasing aortic stiffness Background — Few population studies addressed the prognostic significance of aortic pulse wave velocity ( APWV ) above and beyond other cardiovascular risk factors . Methods and Results — We studied a sex- and age-stratified r and om sample of 1678 Danes aged 40 to 70 years . We used Cox regression to investigate the prognostic value of  APWV , office pulse pressure ( PP ) , and 24-hour ambulatory PP  while adjusting for mean arterial pressure ( MAP ) and other covariates . Over a median follow-up of 9.4 years , the incidence of fatal and nonfatal cardiovascular end points , cardiovascular mortality , and fatal and nonfatal coronary heart disease amounted to 154 , 62 , and 101 cases , respectively . We adjusted for sex , age , body mass index , MAP measured in the office ( conventional PP and APWV ) or by ambulatory monitoring ( 24-hour PP ) , smoking , and alcohol intake . With these adjustments , APWV maintained its prognostic significance in relation to each end point ( P<0.05 ) , whereas office and 24-hour PP lost their predictive value ( P>0.19 ) , except for office PP in relation to coronary heart disease ( P=0.02 ) . For each 1-SD increment in  APWV  ( 3.4 m/s ) , the risk of an event increased by 16 % to 20 % . In sensitivity analyses , APWV still predicted all cardiovascular events after st and ardization to a heart rate of 60 beats per minute , after adjustment for 24-hour MAP instead of office MAP , and /or after additional adjustment for the ratio of total to HDL serum cholesterol and diabetes mellitus at baseline . Conclusions — In a general Danish population , APWV predicted a composite of cardiovascular outcomes above and beyond traditional cardiovascular risk factors , including 24-hour MAP Arterial stiffness is a strong determinant of cardiovascular risk . Pulse wave velocity ( PWV ) is an index of arterial stiffness , and its prognostic value has been repeatedly emphasized . The purpose of the present study was to assess the effect of  heart rate ( HR ) on PWV . Twenty-two subjects with a mean age of 77.8±8.4 ( SD ) years and permanent cardiac pacing were studied . In each subject , PWV was measured at 5 different pacing frequencies in the same session ( 60 , 70 , 80 , 90 , 100 bpm ) , the order of the various frequencies being r and omly determined . Furthermore , to test the reproducibility , a repeat measurement of PWV was obtained in one r and omly selected frequency . Blood pressure ( BP ) was measured by conventional means at each pacing frequency . PWV appeared fairly reproducible because no significant difference was disclosed between the 2 measurements obtained at the same HR level ( P = 0.5 ) and both measurements were strongly correlated ( r = 0.87 , P < 0.001 ) . No significant BP variation was observed during pacing . There was a highly significant effect of HR on PWV estimated by a one-way , within-subjects analysis of variance ( P = 0.01 ) . This study demonstrates that HR is an important factor in the intraindividual variation of PWV in elderly subjects . This raises method ological concern about the measurement of this parameter . St and ardizing PWV for HR level seems m and atory if one wants to interpret PWV changes in clinical trials or in the follow-up of patients Background — Rheumatoid arthritis ( RA ) is associated with increased cardiovascular risk , which is not explained by traditional cardiovascular risk factors but may be due in part to increased aortic stiffness , an independent predictor of cardiovascular mortality . In the present study , our aim was to establish whether aortic stiffness is increased in RA and to investigate the relationship between inflammation and aortic stiffness . In addition , we tested the hypothesis that aortic stiffness could be reduced with anti – tumor necrosis factor-&agr ; ( TNF-&agr ; ) therapy . Methods and Results — Aortic pulse-wave velocity ( PWV ) , augmentation index , and blood pressure were measured in 77 patients with RA and in 142 healthy individuals . Both acute and chronic inflammatory measures and disease activity were determined . The effect of anti-TNF-&agr ; therapy on PWV and endothelial function was measured in 9 RA patients at 0 , 4 , and 12 weeks . Median ( interquartile range ) aortic PWV was significantly higher in subjects with RA than in control subjects ( 8.35 [ 7.14 to 10.24 ] versus 7.52 [ 6.56 to 9.18 ] m/s , respectively ; P=0.005 ) . In multiple regression analyses , aortic PWV correlated independently with age , mean arterial pressure , and log-transformed C-reactive protein ( R2=0.701 ; P<0.0001 ) . Aortic PWV was reduced significantly by anti-TNF-&agr ; therapy ( 8.82±2.04 versus 7.94±1.86 versus 7.68±1.56 m/s at weeks 0 , 4 , and 12 , respectively ; P<0.001 ) ; concomitantly , endothelial function improved . Conclusions — RA is associated with increased aortic stiffness , which correlates with current but not historical measures of inflammation , suggesting that increased aortic stiffness may be reversible . Indeed , anti-TNF-&agr ; therapy  reduced aortic stiffness to a level comparable to that of healthy individuals . Therefore , effective control of inflammation may be of benefit in reducing cardiovascular risk in patients with RA Background —Arterial stiffening with increased pulse pressure is a leading risk factor for cardiovascular disease in the elderly . We tested whether ALT-711 , a novel nonenzymatic breaker of advanced glycation end-product crosslinks , selectively improves arterial compliance and lowers pulse pressure in older individuals with vascular stiffening . Methods and Results —Nine US centers recruited and r and omly assigned subjects with resting arterial pulse pressures > 60 mm Hg and systolic pressures > 140 mm Hg to once-daily ALT-711 ( 210 mg ; n=62 ) or placebo ( n=31 ) for 56 days .  Preexisting antihypertensive treatment ( 90 % of subjects ) was continued during the study . Morning upright blood pressure , stroke volume , cardiac output , systemic vascular resistance , total arterial compliance , carotid-femoral pulse wave velocity , and drug tolerability were assessed . ALT-711 netted a greater decline in pulse pressures than placebo ( −5.3 versus −0.6 mm Hg at day 56;P = 
    Output:
    
The prognostic value of cfPWV may relate to a process of arterial ageing unrelated to classic risk factors other than hypertension