***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: This study assessed the effects of regular coffee drinking on 24-hour ambulatory blood pressure ( ABP ) in normotensive and hypertensive older men and women . Twenty-two normotensive and 26 hypertensive , nonsmoking men and women , with a mean age of 72.1 years ( range , 54 to 89 years ) , took part in the study . After 2 weeks of a caffeine-free diet , subjects were r and omized to continue with the caffeine-free diet and abstain from caffeine-containing drinks or drink instant coffee ( 5 cups per day , equivalent to 300 mg caffeine per day ) in addition to the caffeine-free diet for a further 2 weeks . Change in systolic and diastolic blood pressures ( SBP , DBP ) determined by 24-hour ambulatory BP monitoring showed significant interactions between coffee drinking and hypertension status . In the hypertensive group , rise in mean 24-hour SBP was greater by 4.8 ( SEM , 1.3 ) mm Hg ( P=0.031 ) and increase in mean 24-hour DBP was higher by 3.0 ( 1.0 ) mm Hg ( P=0.010 ) in coffee drinkers than in abstainers . There were no significant differences between abstainers and coffee drinkers in the normotensive group for 24-hour , daytime , or nighttime SBP or DBP . In older men and women with treated or untreated hypertension , ABP increased in coffee drinkers and decreased in abstainers . Restriction of coffee intake may be beneficial in older hypertensive individuals CONTEXT Caffeine acutely increases blood pressure , but the association between habitual consumption of caffeinated beverages and incident hypertension is uncertain . OBJECTIVE To examine the association between caffeine intake and incident hypertension in women . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study conducted in the Nurses ' Health Studies ( NHSs ) I and II of 155,594 US women free from physician-diagnosed hypertension followed up over 12 years ( 1990 - 1991 to 2002 - 2003 question naires ) .  Caffeine intake and possible confounders were ascertained from regularly administered question naires . We also tested the associations with types of caffeinated beverages . MAIN OUTCOME MEASURE Incident physician-diagnosed hypertension . RESULTS During follow-up , 19,541 incident cases of physician-diagnosed hypertension were reported in NHS I and 13,536 in NHS II . In both cohorts , no linear association between  caffeine  consumption and risk of incident hypertension was observed after multivariate adjustment ( NHS I , P for trend = .29 ; NHS II , P for trend = .53 ) . Using categorical analysis , an inverse U-shaped association between caffeine consumption and incident hypertension was found . Compared with participants in the lowest quintile of caffeine consumption , those in the third quintile had a 13 % and 12 % increased risk of hypertension , respectively ( 95 % confidence interval in NHS I , 8%-18 % ; in NHS II , 6%-18 % ) . When study ing individual classes of caffeinated beverages , habitual coffee consumption was not associated with increased risk of hypertension . By contrast , consumption of cola beverages was associated with an increased risk of hypertension , independent of whether it was sugared or diet cola ( P for trend < .001 ) . CONCLUSION No linear association between caffeine consumption and incident hypertension was found . Even though habitual coffee consumption was not associated with an increased risk of hypertension , consumption of sugared or diet cola was associated with it . Further research to eluci date the role of cola beverages in hypertension is warranted Coffee consumption has been associated with elevated  plasma cholesterol . One hundred eighty-one men consumed a st and ard caffeinated coffee for 2 mo followed by r and omization to continue caffeinated coffee ( control ) , change to decaffeinated coffee or no coffee for 2 mo . Plasma low-density-lipoprotein ( LDL ) cholesterol and apolipoprotein B concentrations increased significantly ( 0.12 + /- 0.65 mmol/L , P less than 0.025 ; 0.06 + /- 0.12 g/L , P less than 0.0004 , respectively ) in the group that changed to decaffeinated coffee . In a subgroup ( n = 51 ) , post-heparin lipoprotein lipase decreased significantly more ( -270 mmol free fatty acids . L-1.h-1 , P less than 0.003 ) in the decaffeinated-coffee group . Resting heart rate and blood pressure did not change significantly . Change from caffeinated to decaffeinated coffee increased plasma LDL cholesterol and apolipoprotein B whereas discontinuation of caffeinated coffee revealed no change . This finding suggests that a coffee component other than caffeine is responsible for the LDL cholesterol , apolipoprotein B , and lipase activity changes reported in this investigation BACKGROUND Only 2 prospect i ve studies have previously investigated the association between  coffee consumption  and incident hypertension , and the findings are equivocal . OBJECTIVE The objective was to determine the relation between  coffee  consumption and the incidence of antihypertensive drug treatment . DESIGN We prospect ively followed 24 710 Finnish subjects aged 25 - 64 y without a history of antihypertensive drug treatment , coronary heart disease , or stroke at baseline .  Daily coffee consumption  was assessed by question naires . RESULTS During a mean follow-up period of 13.2 y , 2505 participants started antihypertensive drug treatment . The multivariate-adjusted ( age , sex , study year , education , leisure-time physical activity , smoking , body mass index , high total cholesterol , history of diabetes , and alcohol , tea , fruit , vegetable , sausage , and bread consumption ) hazard ratios for antihypertensive drug treatment associated with the amount of coffee consumed daily ( 0 - 1 , 2 - 3 , 4 - 5 , 6 - 7 , or > or=8 cups ) were 1.00 , 1.29 ( 95 % CI : 1.09 , 1.54 ) , 1.26 ( 95 % CI : 1.06 , 1.49 ) , 1.24 ( 95 % CI : 1.04 , 1.48 ) , and 1.14 ( 95 % CI : 0.94 , 1.37 ) ( P for trend = 0.024 ) , respectively . This trend became marginally significant after additional adjustment for baseline systolic blood pressure ( P for trend = 0.077 ) . CONCLUSIONS The results indicate that coffee drinking seems to increase the risk of antihypertensive drug treatment , and this risk was higher in subjects with low-to-moderate coffee intakes ; however , there was no significantly increased trend in drinkers of approximately 1 cup ( 100 mL)/d or > or=8 cups/d BACKGROUND AND AIM Coffee is rich in chlorogenic acids ( CGA ) , whose metabolites may have beneficial effects such as anti-hypertensive effects . However , trial results concerning the effects of coffee on blood pressure ( BP ) are not consistent . A recent study suggested that hydroxyhydroquinone ( HHQ ) , produced by the roasting of green coffee beans , inhibits the effect of CGA . In the present study , the dose-response for CGA in HHQ-free coffee on BP were investigated in mildly hypertensive men and women . METHODS AND RESULTS The trial design was a double-blind , r and omized controlled trial , with five study groups including , control , zero-dose , low-dose , middle-dose and high-dose . The control beverage was identical to ordinary coffee . The others contained reduced HHQ levels , compared to ordinary coffee , and the CGA were adjusted in target concentration . A total of 203 subjects were r and omly allocated . Each subject drank one cup of coffee per day . The study involved a screening and a baseline observation period of 6 weeks and an intervention period of 4 weeks . BP response showed  CGA  has an anti-hypertensive effect in a dose-dependent manner in HHQ-free coffee , and ordinary coffee showed almost no effect . As a result , a significant correlation between BP change and the three dose-response patterns was observed ( p<0.001 ) . CONCLUSIONS This study demonstrates a dose-dependent decrease in BP for CGA in HHQ-free coffee The effects of coffee on blood pressure and heart-rate and the mediating effect of two common brewing methods , were studied in a r and omized trial in 107 young , normotensive adults . After a three-week run-in period , subjects were r and omly assigned to one of three groups , receiving either ( 1 ) 4 - 6 cups filtered coffee per day , ( 2 ) 4 - 6 cups boiled coffee per day , or ( 3 ) no coffee at all for a period of nine weeks . Because all participants consumed filtered coffee before the trial , the group continuing on filtered coffee was considered as the reference group . Both systolic ( SBP ) and diastolic blood pressure ( DBP ) decreased in the abstinence group . Compared to the filter group , only the fall in SBP after 9 weeks was statistically significant , -6.1 mmHg ( 95 % confidence limits -10.8 , -1.4 ) . After adjustment for SBP at baseline and body weight change during the study , the observed reduction decreased , to -3.4 mmHg ( -7.1 , 0.3 ) . The patterns for SBP and DBP were remarkably similar in the groups using either filtered coffee or boiled coffee . After 9 weeks of boiled coffee , mean changes from baseline for SBP and DBP were 0.4 mmHg ( -3.7 , 4.5 ) and -0.1 mmHg ( -3.4 , 3.2 ) , compared to the filter group . The heart rate showed a slight , non-significant decrease in the abstinence group . In conclusion , these findings suggest that abstinence from coffee for a period of several weeks may slightly reduce blood pressure in young normotensive subjects In a double-blind crossover trial , the effect of 4 week daily ingestion of eight cups of regular coffee ( corresponding to 504 mg caffeine ) vs eight cups of decaffeinated coffee was studied . Blood pressure , heart rate and urinary catecholamines were measured in eight healthy , young volunteers . In both groups , regular coffee immediately led to a significant increase in mean blood pressure ( + 3 and + 5 mm Hg respectively ) . The difference between both groups , however , existed only in the first 3 to 5 days of ingestion of regular coffee . On day 5 after ingestion of regular coffee , and thereafter in weekly intervals , no significant increase in catecholamine excretion was observed . The data suggest that long-term consumption of large amounts of coffee leads to only a small and transient rise in mean blood pressure . This may be due to an adaptation phenomenon . Therefore , continuous heavy coffee ingestion ( eight cups/day for 4 weeks ) by young persons does not appear to involve a risk of the development of hypertension Objective : Earlier studies and trials have shown a serum cholesterol raising effect of unfiltered coffee , which is reduced by about 80 % in filtered coffee . Recent cross-sectional studies and trials , however , have indicated that filtered coffee may have a more pronounced serum cholesterol raising effect than previously anticipated . The objective of this controlled study was to assess the effects of the intake and abstention of filtered brewed coffee on blood lipids . Design : A prospect i ve , controlled study with four consecutive trial periods . The first and third periods were 3 weeks of total coffee abstention . The second and fourth periods consisted of 4 weeks with the subjects consuming 600 ml filter brewed coffee/day . Setting : Free-living population . Volunteers . Subjects : A total of 121 healthy , nonsmoking men and women aged 29–65 y. Interventions : Not applicable . Main outcome measures : Serum total cholesterol , serum HDL cholesterol , serum triglycerides , serum lipoprotein ( a ) ( Lp(a ) ) , blood pressure and heart rate . Results : The two coffee abstention periods were associated with a decline in serum cholesterol of 0.22 mmol/l ( 95 % CI −0.31 , −0.13 ) and 0.36 mmol/l ( 95 % CI −0.46 , −0.26 ) , respectively . Filtered coffee/day 600 ml increased serum cholesterol by 0.25 mmol/l ( 95 % CI 0.15 , 0.36 ) and 0.15 mmol/l ( 95 % CI 0.04 , 0.26 ) during the two coffee drinking periods . Conclusions : Coffee abstention for 3 weeks decreased total serum cholesterol by 0.22–0.36 mmol/l . A volume of 600 ml ( about four cups ) of filtered coffee/day during 4 weeks raised total serum cholesterol by 0.15–0.25 mmol/l . Sponsorship : None Background . The longitudinal relationship between coffee use and  hypertension  is not well known . Aim . We did a prospect i ve study to investigate if there is a temporal relationship between coffee consumption and development of sustained hypertension . Method . We assessed 1107 white subjects with elevated blood pressure who were followed up for 6.4 years .  Coffee intake and other life‐style factors were ascertained from regularly administered question naires . Incident 
    Output:
    
Low- quality evidence did not show any statistically significant effect of coffee consumption on BP or the risk of hypertension .
Given the quality of the currently available evidence , no recommendation can be made for or against coffee consumption as it relates to BP and hypertension