***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 Hypertension Prevention Trial ( HPT ) was a r and omized , controlled , multicenter ( four clinics , four re source centers ) trial design ed to test the feasibility of achieving and sustaining dietary changes in the intake of calories , sodium , and potassium and to assess the effect of those changes on blood pressure in a normotensive population . The trial involved 841 men and women ( plus a test cohort of 78 ) who , at the first baseline ( BL ) examination were in the age range of 25 - 49 years and had diastolic blood pressure ( DBP ) greater than or equal to 76 but less than 100 mm Hg ( average of two readings ) , and at the examination prior to r and omization ( BL 2 ) , had DBP greater than or equal to 78 but less than 90 mm Hg ( also averaged ) . Participants were r and omly assigned to a control treatment group ( no dietary counseling ) or to one of four dietary treatment groups involving counseling design ed to reduce calorie intake , reduce sodium intake , reduce sodium and calorie intake , and reduce sodium and increase potassium intake .  This chapter describes the process of recruiting participants for the trial . Methods used to identify and contact study participants are presented . Details of the steps involved in the recruitment process and strategies for reducing costs are discussed Phase I of the Trials of Hypertension Prevention ( TOHP ) was a r and omized , multicenter investigation that included double-blind , placebo-controlled testing of calcium and magnesium supplementation among 698 healthy adults ( 10.5 % blacks and 31 % women ) aged 30 to 54 years with high-normal diastolic blood pressure ( DBP ) ( 80 to 89 mm Hg ) . Very high compliance ( 94 to 96 % by pill counts ) with daily doses of 1 g of calcium ( carbonate ) , 360 mg of magnesium ( diglycine ) , or placebos was corroborated for the active supplements by significant net increases in all urine and serum compliance measures in white men and for urine compliance measures in white women . Overall , neither calcium nor magnesium produced significant changes in blood pressure at 3 and 6 months . Analyses stratified by baseline intakes of calcium , magnesium , sodium , or initial blood pressures also showed no effect of supplementation . These analyses suggested that calcium supplementation may have result ed in a DBP decrease in white women and that response modifiers in this subgroup might have included lower initial urinary calcium levels , urinary sodium levels , or lower body mass index . However , overall analyses indicated that calcium and magnesium supplements are unlikely to lower blood pressure in adults with high-normal DBP . The subgroup analyses , useful to formulate hypotheses , raise the possibility of a benefit to white women , which requires testing in future trials 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 The Hypertension Prevention Trial ( HPT ) , was a r and omized , controlled , multicenter ( four clinics , four re source centers ) trial design ed to test the feasibility of achieving and sustaining dietary changes in the intake of calories , sodium , and potassium and to assess the effect of those changes on blood pressure in a normotensive population . The trial involved 841 men and women ( plus a test cohort of 78 ) who , at the first baseline ( BL ) examination were in the age range of 25 - 49 years and had diastolic blood pressure ( DBP ) greater than or equal to 76 but less than 100 mm Hg ( average of two readings ) , and at the examination prior to r and omization ( BL 2 ) had DBP greater than or equal to 78 but less than 90 mm Hg ( also averaged ) . Participants were r and omly assigned to a control treatment group ( no dietary counseling ) or to one of four dietary treatment groups involving counseling design ed to reduce calorie intake , reduce sodium intake , reduce sodium and calorie intake , and reduce sodium and increase potassium intake . This chapter describes HPT procedures for training and certifying clinic staff , for data entry checks and data audits of its distributed data entry system , and for inspecting clinical equipment . Replicate analyses were performed regularly by the two arms of the Data Coordinating Center . The Food Coding Center and the Central Laboratory were evaluated by both internal and external monitoring techniques . The performance monitoring report , prepared semiannually for the governing committees of the HPT , reported on the effectiveness of quality assurance procedures and served to alert staff to developing problems The Hypertension Prevention Trial ( HPT ) was a r and omized , controlled , multicenter ( four clinics , four re source centers ) trial design ed to test the feasibility of achieving and sustaining dietary changes in the intake of calories , sodium , and potassium and to assess the effect of those changes on blood pressure in a normotensive population . The trial involved 841 men and women ( plus a test cohort of 78 ) who , at the first baseline ( BL ) examination were in the age range of 25 - 49 years and had diastolic pressure ( DBP ) greater than or equal to 76 but less than 100 mm Hg ( average of two readings ) , and at the examination prior to r and omization ( BL 2 ) , had DBP greater than or equal to 78 but less than 90 mm Hg ( also averaged ) . Participants were r and omly assigned to a control treatment group ( no dietary counseling ) or to one of four dietary treatment groups involving counseling design ed to reduce calorie intake ; reduce sodium intake , reduce sodium and calorie intake , and reduce sodium and increase potassium intake .  This chapter presents HPT baseline characteristics by weight stratum , clinic , and treatment group for various demographic , medical history , and nutritional characteristics , for several physiologic variables used in monitoring treatment compliance , and for blood pressure . The degree of comparability observed among treatment groups was within the range expected for the r and omization procedure used The Hypertension Prevention Trial ( HPT ) was a r and omized , controlled , multicenter ( four clinics , four re source centers ) trial design ed to test the feasibility of achieving and sustaining dietary changes in the intake of calories , sodium , and potassium and to assess the effect of those changes on blood pressure in a normotensive population . The trial involved 841 men and women ( plus a test cohort of 78 ) who , at the first baseline ( BL ) examination , were in the age range of 25 - 49 years and had diastolic blood pressure ( DBP ) greater than or equal to 76 but less than 100 mm Hg ( average of two readings ) , and at the examination prior to r and omization ( BL 2 ) had DBP greater than or equal to 78 but less than 90 mm Hg ( also averaged ) . Participants were r and omly assigned to a control treatment group ( no dietary counseling ) or to one of four dietary treatment groups involving counseling design ed to reduce calorie intake , reduce sodium intake , reduce sodium and calorie intake , and reduce sodium and increase potassium intake . Dietary counseling was provided primarily in group setting s and was aim ed at changing participants ' shopping , cooking , and eating habits related to a design ated treatment assignment . The effect of dietary counseling was measured through changes in urinary excretion of sodium and potassium , changes in body weight , and changes in reported food intake based on 24-hour food records . Blood pressure changes during the 3-year course of followup were based on measurements taken at 6-month intervals from enrollment using a r and om-zero sphygmomanometer . This chapter provides a general description of the design and methods of the HPT and the underlying rationale for decisions affecting the design BACKGROUND The beneficial effects of potassium-enriched salt on blood pressure have been reported in a few short-term trials . The long-term effects of potassium-enriched salt on cardiovascular mortality have not been carefully studied . OBJECTIVE The objective was to examine the effects of potassium-enriched salt on cardiovascular disease ( CVD ) mortality and medical expenditures in elderly veterans . DESIGN Five kitchens of a veteran retirement home were r and omized into 2 groups ( experimental or control ) and veterans assigned to those kitchens were given either potassium-enriched salt ( experimental group ) or regular salt ( control group ) for approximately 31 mo . Information on death , health insurance cl aims , and date s that veterans moved in or out of the home was gathered . RESULTS Altogether , 1981 veterans , 768 in the experimental [ x ( + /-SD ) age : 74.8 + /- 7.1 y ] and 1213 in the control ( age : 74.9 + /- 6.7 y ) groups , were included in the analysis . The experimental group had better CVD survivorship than did the control group . The incidence of CVD-related deaths was 13.1 per 1000 persons ( 27 deaths in 2057 person-years ) and 20.5 per 1000 ( 66 deaths in 3218 person-years ) for the experimental and control groups , respectively . A significant reduction in CVD mortality ( age-adjusted hazard ratio : 0.59 ; 95 % CI : 0.37 , 0.95 ) was observed in the experimental group . Persons in the experimental group lived 0.3 - 0.90 y longer and spent significantly less ( approximately US Dollars 426/y ) in inpatient care for CVD than did the control group , after control for age and previous hospitalization expenditures . CONCLUSIONS This study showed a long-term beneficial effect on CVD mortality and medical expenditure associated with a switch from regular salt to potassium-enriched salt in a group of elderly veterans . The effect was likely due to a major increase in potassium and a moderate reduction in sodium intakes The Hypertension Prevention Trial ( HPT ) was a r and omized unmasked multicenter trial design ed to address questions concerning the feasibility and efficacy of dietary intervention in the primary prevention of hypertension . Participants in the diet treatments  were given counseling to achieve and sustain changes in calorie , sodium , and /or potassium intake . Diet composition , sodium and potassium excretion , and body weight were assessed for all participants at 6-mo intervals over 3 y. This paper provides information about extent and possible sources of bias in the dietary assessment methodology used in the HPT . Estimates of nutrient intake were derived from food records , urinalysis , and measurement of body weight . Reported potassium intake increased and sodium intake declined to a greater degree during the study than did potassium and sodium excretion . Our results indicate that repeated assessment s of diet , which depend upon participant recording , may not accurately represent usual diet in a dietary trial To examine the long-term effects of weight loss and dietary sodium reduction on the incidence of hypertension , we studied 181 men and women who participated in the Trials of Hypertension Prevention , phase 1 , in Baltimore , 
    Output:
    
Salt restriction increased the risk of all-cause mortality in those with heart failure ( end of trial RR 2.59 , 1.04 - 6.44 , 21 deaths).We found no information on participant 's health-related quality of life .
Despite collating more event data than previous systematic review s of RCTs ( 665 deaths in some 6,250 participants ) there is still insufficient power to exclude clinical ly important effects of reduced dietary salt on mortality or CVD morbidity .
Our estimates of benefits from dietary salt restriction are consistent with the predicted small effects on clinical events attributable to the small BP reduction achieved