***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: A reduction in salt intake lowers blood pressure . However , most previous trials were in whites with few in blacks and Asians . Salt reduction may also reduce other cardiovascular risk factors ( eg , urinary albumin excretion , arterial stiffness ) . However , few well-controlled trials have studied these effects . We carried out a r and omized double-blind crossover trial of salt restriction with slow sodium or placebo , each for 6 weeks , in 71 whites , 69 blacks , and 29 Asians with untreated mildly raised blood pressure .  From slow sodium to placebo , urinary sodium was reduced from 165±58 ( ±SD ) to 110±49 mmol/24 hours ( 9.7 to 6.5 g/d salt ) . With this reduction in salt intake , there was a significant decrease in blood pressure from 146±13/91±8 to 141±12/88±9 mm Hg ( P<0.001 ) , urinary albumin from 10.2 ( IQR : 6.8 to 18.9 ) to 9.1 ( 6.6 to 14.0 ) mg/24 hours ( P<0.001 ) , albumin/creatinine ratio from 0.81 ( 0.47 to 1.43 ) to 0.66 ( 0.44 to 1.22 ) mg/mmol ( P<0.001 ) , and carotid-femoral pulse wave velocity from 11.5±2.3 to 11.1±1.9 m/s ( P<0.01 ) . Subgroup analysis showed that the reductions in blood pressure and urinary albumin/creatinine ratio were significant in all groups , and the decrease in pulse wave velocity was significant in blacks only . These results demonstrate that a modest reduction in salt intake , approximately the amount of the current public health recommendations , causes significant falls in blood pressure in all 3 ethnic groups . Furthermore , it reduces urinary albumin and improves large artery compliance . Although both could be attributable to the falls in blood pressure , they may carry additional benefits on reducing cardiovascular disease above that obtained from the blood pressure falls alone Objective — To study the possible pathophysiological implication s of long continued dietary sodium restriction in pregnancy Objective : To determine the blood pressure responses in elderly normotensive men and women to dietary sodium and to the diunsaturated fatty acid dihomogammalinolenic acid ( DGLA ) , which is derived from linoleic acid Design : Blood pressure responses were assessed in 66 subjects ( 36 male , 30 female ; mean age 65 years ) on two diets differing by approximately 70mmol/day sodium , combined with daily supplements of either 1 g DGLA or 1 g safflower oil  , giving a four-group parallel design . After a common period of salt restriction and salt supplementation , two sets of parallel groups continued with either salt or placebo tablets . The study was blinded , except for dietary adjustments based on 24-h urinary sodium excretion values measured once every 2 weeks . Blood pressures were also measured automatically once every 2 weeks Results : Urinary sodium excretion ( sodium intake ) correlated significantly with systolic and diastolic blood pressures . A strong interaction with sex ( P < 0.001 for systolic blood pressure ) reflected greater responsiveness in women to changing sodium intake . A second major determinant of blood pressure responsiveness was the waist : hip ratio , an index of central obesity ; this correlation was independent of the initial sodium intake , initial blood pressure or body mass index . The waist : hip ratio was a powerful predictor of blood pressure changes with sodium intake in women only ; women with and roid fat distribution were , similarly to men , less sensitive to dietary sodium . Daily supplements of 1 g DGLA doubled the concentration of DGLA in plasma but did not influence blood pressure Conclusions : Among elderly normotensive subjects , women responded to changes in sodium intake with greater changes in blood pressure than men did . Furthermore , this response was strongly related to the gynaecoid distribution of body The aim of this study was to determine whether moderate restriction of dietary salt intake leads to an additional fall in blood pressure in treated hypertensive men who are asked to simultaneously reduce their usual alcohol intake . Sixty-three subjects entered an initial 2-week familiarization period during which they continued their usual alcohol intake and commenced a " low sodium " diet ( less than 60 mmol/day ) supplemented with 100 mmol sodium chloride per day as enteric-coated tablets . Subjects were then r and omly assigned to either drink a low alcohol beer alone for a 4-week period ( reducing their self-reported alcohol consumption from 537 to 57 ml/week ) or to continue their usual alcohol intake ( 543 versus 557 ml/week ) . Within the low and normal alcohol intake groups , subjects were assigned to either a low or normal sodium intake . The low sodium groups continued the sodium-restricted diet but were switched to placebo sodium chloride tablets for the 4 weeks . This result ed in a fall in the 24-hour urinary sodium excretion from 144 to 69 mmol/day . The normal sodium groups continued the low sodium diet but kept taking 100 mmol/day of the sodium chloride tablets , and their urinary sodium excretion remained unchanged ( 125 versus 142 mmol/day ) . Regular antihypertensive therapy was continued throughout . Fifty-nine subjects completed the trial . In those who reduced their alcohol intake there was a fall in both systolic blood pressure ( -5.4 mm Hg supine , p less than 0.01 ) and diastolic blood pressure ( -3.2 mm Hg supine , p less than 0.01 ) . ( ABSTRACT TRUNCATED AT 250 WORDS This study was design ed to evaluate in healthy volunteers the renal hemodynamic and tubular effects of the orally active angiotensin II receptor antagonist losartan ( DuP 753 or MK 954 ) . Losartan or a placebo was administered to 23 subjects maintained on a high-sodium ( 200 mmol/d ) or a low-sodium ( 50 mmol/d ) diet in a r and omized , double-blind , crossover study . The two 6-day diet periods were separated by a 5-day washout period . On day 6 , the subjects were water loaded , and blood pressure , renal hemodynamics , and urinary electrolyte excretion were measured for 6 hours after a single 100-mg oral dose of losartan ( n = 16 ) or placebo ( n = 7 ) . Losartan induced no significant changes in blood pressure , glomerular filtration rate , or renal blood flow in these water-loaded subjects , whatever the sodium diet . In subjects on a low-salt diet , losartan markedly increased urinary sodium excretion from 115 + /- 9 to 207 + /- 21 mumol/min ( P < .05 ) . The fractional excretion of endogenous lithium was unchanged , suggesting no effect of losartan on the early proximal tubule in our experimental conditions . Losartan also increased urine flow rate ( from 10.5 + /- 0.4 to 13.1 + /- 0.6 mL/min , P < .05 ) ; urinary potassium excretion ( from 117 + /- 6.9 to 155 + /- 11 mumol/min ) ; and the excretion of chloride , magnesium , calcium , and phosphate . In subjects on a high-salt diet , similar effects of losartan were observed , but the changes induced by the angiotensin II antagonist did not reach statistical significance . In addition , losartan demonstrated significant uricosuric properties with both sodium diets . ( ABSTRACT TRUNCATED AT 250 WORDS The aim of the present study was to evaluate the effects of a normal-sodium ( 120 mmol sodium ) diet compared with a low-sodium diet ( 80 mmol sodium ) on readmissions for CHF ( congestive heart failure ) during 180 days of follow-up in compensated patients with CHF . A total of 232 compensated CHF patients ( 88 female and 144 male ; New York Heart Association class II-IV ; 55 - 83 years of age , ejection fraction < 35 % and serum creatinine < 2 mg/dl ) were r and omized into two groups : group 1 contained 118 patients ( 45 females and 73 males ) receiving a normal-sodium diet plus oral furosemide [ 250 - 500 mg , b.i.d . ( twice a day ) ] ; and group 2 contained 114 patients ( 43 females and 71 males ) receiving a low-sodium diet plus oral furosemide ( 250 - 500 mg , b.i.d . ) . The treatment was given at 30 days after discharge and for 180 days , in association with a fluid intake of 1000 ml per day . Signs of CHF , body weight , blood pressure , heart rate , laboratory parameters , ECG , echocardiogram , levels of BNP ( brain natriuretic peptide ) and aldosterone levels , and PRA ( plasma renin activity ) were examined at baseline ( 30 days after discharge ) and after 180 days . The normal-sodium group had a significant reduction ( P<0.05 ) in readmissions . BNP values were lower in the normal-sodium group compared with the low sodium group ( 685+/-255 compared with 425+/-125 pg/ml respectively ; P<0.0001 ) . Significant ( P<0.0001 ) increases in aldosterone and PRA were observed in the low-sodium group during follow-up , whereas the normal-sodium group had a small significant reduction ( P=0.039 ) in aldosterone levels and no significant difference in PRA . After 180 days of follow-up , aldosterone levels and PRA were significantly ( P<0.0001 ) higher in the low-sodium group . The normal-sodium group had a lower incidence of rehospitalization during follow-up and a significant decrease in plasma BNP and aldosterone levels , and PRA . The results of the present study show that a normal-sodium diet improves outcome , and sodium depletion has detrimental renal and neurohormonal effects with worse clinical outcome in compensated CHF patients . Further studies are required to determine if this is due to a high dose of diuretic or the low-sodium diet Objective : To examine effects of dietary fish oil supplementation with sodium restriction on  blood pressure in the elderly . Design : In a double-blind dietary intervention lasting 4 weeks , parallel comparisons of blood pressure were made in volunteers assigned to one of four treatment groups : fish oil and low sodium ; fish oil and normal sodium ; sunflower oil and low sodium ; or sunflower oil and normal sodium . Setting : Subjects lived at home and attended our nutrition research clinic at fortnightly intervals for dietary counselling and blood pressure measurement . Participants : Health volunteers aged 60 - 80 years were sought by advertisement . A total of 114 men and women were enrolled in two cohorts ; 106 , with an initial mean blood pressure of 132/77 mmHg , satisfactorily completed the study . Intervention : All subjects adopted a low-sodium diet and dietary changes were effected by double-blind administration of slow-release sodium chloride or placebo tablets , along with capsules containing either fish or sunflower oil . Main outcome measure : The primary measure was the within-subject change in blood pressure after 4 weeks of intervention in each dietary treatment group . Results : Urinary sodium excretion in subjects on low-sodium diets decreased whilst potassium excretion was unaffected . Systolic blood pressure ( SBP ) fell in the group taking sunflower oil with low sodium , but there was only a transient fall in diastolic blood pressure ( DBP ) . In those taking fish oil with normal sodium , the change in blood pressure was not significant , except after adjustment for initial blood pressure and weight changes . When fish oil was combined with low sodium , however , both SBP and DBP were substantially reduced ; the reduction in DBP was significantly greater than in the other treatment groups . Conclusion : Dietary fish oil and sodium restriction can interact to lower DBP in the elderly If high sodium intake is involved in the pathogenesis of essential hypertension , the effects of changing the sodium intake should be demonstrable in the susceptible part of the normotensive population . Therefore , we have investigated the effects of moderate salt restriction in 52 young normotensive subjects with and without a family history of hypertension ; 22 ( 42 % ) responded to  moderate salt restriction  ( 200 to 50 mmol/day ) over 2 weeks , with a significant fall in blood pressure shown by continuous automatic blood pressure recordings . Accordingly , these subjects were classified as salt-sensitive , and the remainder as salt-resistant . Compared to salt-resistant subjects , salt-sensitive subjects showed a 2.5-fold higher incidence of a positive family history of hypertension ( p less than 0.01 ) , and a significantly higher blood pressure and lower salivary sodium concentration during the usual high sodium diet . Although there were no differences in Na , K-ATPase activity and in Na-K cotransport of erythrocytes , the pressor response to infused norepinephrine in salt-sensitive subjects was double that of salt-resistant subjects independent of the diet and this was linked to indirect evidence for enhanced proximal tubular sodium reabsorption . On 
    Output:
    
Sodium reduction result ed in a 1 % decrease in blood pressure in normotensives  , a 3.5 % decrease in hypertensives , a significant increase in plasma renin , plasma aldosterone , plasma adrenaline and plasma noradrenaline , a 2.5 % increase in cholesterol , and a 7 % increase in triglyceride .
In general , these effects were stable in studies lasting for 2 weeks or more