***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: The objective of this study was to determine the impact of stress reduction on blood pressure ( BP ) in adolescents by the Transcendental Meditation ( TM ) program .  African-American adolescents ( aged 16.2 + /- 1.3 years ) with high normal systolic BP were r and omly assigned to either 4-month TM ( n = 50 ) or health education control ( n = 50 ) groups . Ambulatory 24-h BP measures were recorded at pretest , 2- and 4-month post-tests , and 4-month follow-up . Greater decreases in daytime systolic BP ( P < .04 ) and diastolic BP ( P < .06 ) in the TM group compared with the control group across the visits demonstrate a beneficial impact of the TM program in youth at risk for the development of hypertension Background Slow , controlled breathing has been shown by cross-spectral techniques to potentiate arterial baroreflex control of heart rate . However , crucial aspects of the effects of slow breathing on the arterial baroreflex remain unsettled , namely whether the major function of the arterial baroreflex ( i.e. the control of blood pressure ) is also potentiated and whether baroreflex function is differentially modulated according to the age of the individual . Objective To examine the bradycardic and depressor responses to selective carotid baroreceptor stimulation by the neck chamber technique ( −15 and −30 mmHg neck suction ) and the cross-spectral R – R interval/systolic blood pressure relationship ( α index ) . Methods In 24 resting , supine healthy male volunteers ( aged 19–66 years , mean ±SEM 37.5 ± 3.19 years ) , blood pressure ( Finapres ) , R – R interval ( electrocardiogram ) and ventilation ( impedance ) were recorded continuously . Both assessment s were performed during spontaneous breathing and during 6 cycles/min controlled ventilation in r and om order . Results The depressor and bradycardic responses to neck suction  were significantly larger during slow breathing than in spontaneous breathing ( + 32 and + 85 % , respectively ; both P < 0.01 ) . The α index was also significantly larger during slow breathing ( + 62 % ; P < 0.01 ) . Even after the volunteers were divided into older ( > 50 years , n = 9 ) and younger ( < 30 years , n = 9 ) groups , the baroreflex potentiation related to slow breathing was clearcut and significant for both the depressor ( + 46 and + 24 % older and younger volunteers ; both P < 0.01 ) and the bradycardic ( + 130 and + 73 % older and younger volunteers ; both P < 0.01 ) responses . When the assessment was made by computing the cross-spectral α index , a marked potentiation related to slow breathing was observed in younger volunteers ( + 99 % ; P < 0.01 ) , whereas in older volunteers only a trend to an enhancement ( by 32 % ; P < 0.055 ) was observed . Conclusions Slow controlled breathing is associated with potentiation of both the depressor and the cardio-inhibitory components of the arterial baroreflex , the potentiation being largely similar regardless of the age of the individual In man evaluation of neural cardiovascular regulation makes use of a variety of tests which address the excitatory and reflex inhibitory neural influences that control circulation . Because interpretation of these tests is largely based on the magnitude of the elicited haemodynamic responses , their reproducibility in any given subject is critical . In 39 subjects with continuous blood pressure ( intra-arterial catheter ) and heart rate monitoring we measured the blood pressure and heart rate rises during h and -grip and cold-pressor test , the heart rate changes occurring during baroreceptor stimulation and deactivation by injection of phenylephrine and trinitroglycerine , and the heart rate and blood pressure changes occurring with alteration in carotid baroreceptor activity by a neck chamber . Each test was carefully st and ardized and performed at 30 min intervals for a total of six times in each subject . The results showed that the responses to any test were clearly different from one another and that this occurred in all subjects studied . For the group as a whole the average response variability ( coefficient of variation ) ranged from 10.2 % for the blood pressure response to carotid baroreceptor stimulation to 44.2 % for the heart rate response to cold-pressor test . The variability of the responses was not related to basal blood pressure or heart rate , nor to the temporal sequence of the test performance . Thus tests employed for study ing neural cardiovascular control in man produce responses whose reproducibility is limited . This phenomenon may make it more difficult to define the response magnitude typical of each subject , as well as its comparison in different conditions and diseases OBJECTIVE --To establish whether stress management had a larger effect than a control treatment on resting blood pressure , ambulatory blood pressure , and left ventricular mass . DESIGN --A 12 week baseline period of habituation to measurement of blood pressure was followed by r and omisation to either stress management or mild exercise for six months and follow up six months later . SETTING --General practice , district general hospital , and medical school . PATIENTS --Of the 184 patients aged under 60 with mild primary hypertension who entered the baseline habituation period , 88 were excluded because they failed to meet the entry criteria or they withdrew from the study . The remaining 46 men and 50 women underwent treatment . INTERVENTIONS --10 clinical sessions and daily practice at home of either stress management based on relaxation or non-aerobic stretching exercises . Mildly stressful 15 minute interviews before and after treatment . MAIN OUTCOME MEASURES --Diastolic and systolic blood pressure in the clinic and during 12 hours of ambulatory recording , and left ventricular mass measured by echocardiography . RESULTS --The patients ' blood pressure fell during habituation ( systolic pressure from 152 mmHg to 140 mmHg , diastolic pressure from 98 to 93 mm Hg ) , but neither resting nor ambulatory blood pressure was changed by the treatments . Left ventricular mass was also unchanged . Blood pressure rose during the stressful interview , but this rise was reduced by stress management ( systolic pressure rose by 7.4 mmHg before treatment and by 3.7 mmHg after treatment ) . CONCLUSION --Stress management of a type advocated for treating mild primary hypertension is ineffective in lowering blood pressure in patients who are well habituated to measuring blood pressure 34 hypertensive patients were assigned at r and om either to six weeks ' treatment by yoga relaxation methods with bio-feedback or to placebo therapy ( general relaxation ) . Both groups showed a reduction in blood-pressure ( from 168/100 to 141/84 mm . Hg in the treated group and from 169/101 to 160/96 mm Hg in the control group ) . The difference was highly significant . The control group was then trained in yoga relaxation , and their blood-pressure fell to that of the other group ( now used as controls ) BACKGROUND In chronic heart failure ( CHF ) , impaired pulmonary function can independently contribute to oxygen desaturation and reduced physical activity . We investigated the effect of breathing rate on oxygen saturation and other respiratory indices . METHODS  Arterial oxygen saturation ( SaO2 ) and respiratory indices  were recorded during spontaneous breathing ( baseline ) and during controlled breathing at 15 , six , and three breaths per min in 50 patients with CHF and in 11 healthy volunteers ( controls ) . 15 patients with CHF were r and omly allocated 1 month of respiratory training to decrease their respiratory rate to six breaths per min . Respiratory indices  were recorded before training , at the end of training , and 1 month after training . FINDINGS During spontaneous breathing , mean SaO2 was lower in CHF patients than in controls ( 91 - 4 % [ SD 0.4 ] vs 95.4 % [ 0.2 ] , p<0.001 ) . Controlled breathing increased SaO2 at all breathing rates in patients with CHF . Compared with baseline , minute ventilation increased at 15 breaths per min ( + 45.9 % [ 9.8 ] , p<0.01 ) , did not change at six breaths per min , and decreased at three breaths per min ( -40.3 % [ 4.8 ] , p<0.001 ) . In the nine CHF patients who had 1 month of respiratory training , resting SaO2 increased from 92.5 % ( 0.3 ) at baseline to 93.2 % ( 0.4 ) ( p<0.05 ) , their breathing rate per min decreased from 13.4 ( 1.5 ) to 7.6 ( 1.9 ) ( p<0.001 ) , peak oxygen consumption increased from 1157 ( 83 ) to 1368 ( 110 ) L/min ( p<0.05 ) , exercise time increased from 583 ( 29 ) to 615 ( 23 ) min/s ( p<0.05 ) , and perception of dyspnoea reduced from a score of 19.0 ( 0.4 ) to 17.3 ( 0.9 ) on the Borg scale ( p<0.05 ) . There were no changes in the respiratory indices in the patients who did not have respiratory training . INTERPRETATION Slowing respiratory rate reduces dyspnoea and improves both resting pulmonary gas exchange and exercise performance in patients with CHF CONTEXT Weight loss , sodium reduction , increased physical activity , and limited alcohol intake are established recommendations that reduce blood pressure ( BP ) . The Dietary Approaches to Stop Hypertension ( DASH ) diet also lowers BP . To date , no trial has evaluated the effects of simultaneously implementing these lifestyle recommendations . OBJECTIVE To determine the effect on BP of 2 multicomponent , behavioral interventions . DESIGN , SETTING , AND PARTICIPANTS R and omized trial with enrollment at 4 clinical centers ( January 2000-June 2001 ) among 810 adults ( mean [ SD ] age , 50 [ 8.9 ] years ; 62 % women ; 34 % African American ) with above-optimal BP , including stage 1 hypertension ( 120 - 159 mm Hg systolic and 80 - 95 mm Hg diastolic ) , and who were not taking antihypertensive medications . INTERVENTION Participants were r and omized to one of 3 intervention groups : ( 1 ) " established , " a behavioral intervention that implemented established recommendations ( n = 268 ) ; ( 2 ) " established plus DASH,"which also implemented the DASH diet ( n = 269 ) ; and ( 3 ) an " advice only " comparison group ( n = 273 ) . MAIN OUTCOME MEASURES Blood pressure measurement and hypertension status at 6 months . RESULTS Both behavioral interventions significantly reduced weight , improved fitness , and lowered sodium intake . The established plus DASH intervention also increased fruit , vegetable , and dairy intake . Across the groups , gradients in BP and hypertensive status were evident . After subtracting change in advice only , the mean net reduction in systolic BP was 3.7 mm Hg ( P<.001 ) in the established group and 4.3 mm Hg ( P<.001 ) in the established plus DASH group ; the systolic BP difference between the established and established plus DASH groups was 0.6 mm Hg ( P = .43 ) . Compared with the baseline hypertension prevalence of 38 % , the prevalence at 6 months was 26 % in the advice only group , 17 % in the established group ( P = .01 compared with the advice only group ) , and 12 % in the established plus DASH group ( P<.001 compared with the advice only group ; P = .12 compared with the established group ) . The prevalence of optimal BP ( < 120 mm Hg systolic and < 80 mm Hg diastolic ) was 19 % in the advice only group , 30 % in the established group ( P = .005 compared with the advice only group ) , and 35 % in the established plus DASH group ( P<.001 compared with the advice only group ; P = .24 compared with the established group ) . CONCLUSION Individuals with above-optimal BP , including stage 1 hypertension , can make multiple lifestyle changes that lower BP and reduce their cardiovascular disease risk 
    Output:
    
There is at present insufficient good- quality evidence to conclude whether or not TM has a cumulative positive effect on blood pressure