***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: 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 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 . 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 physician‐diagnosed hypertension was the outcome measure . Results . During the follow‐up , 561 subjects developed sustained hypertension , whereas 546 subjects did not meet the criteria for treatment . Coffee drinkers developed sustained hypertension more frequently than abstainers ( 53.1 % versus 43.9 % , P = 0.007 ) . The incidence of hypertension did not differ between moderate and heavy coffee drinkers . Kaplan‐Meier analysis confirmed that sustained hypertension was developed more frequently by coffee drinkers compared with nondrinkers ( P<0.001 ) . The adjusted relative risk of hypertension was greater in both categories of coffee drinking than in abstainers ( hazard ratio , 95 % confidence limit ( CL ) = 1.24 , 1.06–1.44 ) . The risk of hypertension associated with coffee drinking increased gradually with increasing level of alcohol use ( adjusted P for interaction = 0.005 ) . Conclusions . In subjects screened for stage 1 hypertension a nonlinear association was found between coffee consumption and development of sustained hypertension BACKGROUND Whether the increase in blood pressure with coffee drinking seen in clinical trials persists over time and translates into an increased incidence of hypertension is not known . METHODS We assessed coffee intake in a cohort of 1017 white male former medical students ( mean age , 26 years ) in graduating classes from 1948 to 1964 up to 11 times over a median follow-up of 33 years .  Blood pressure and incidence of hypertension were determined annually by self-report , demonstrated to be accurate in this cohort . RESULTS Consumption of 1 cup of coffee a day raised systolic blood pressure by 0.19 mm Hg ( 95 % confidence interval , 0.02 - 0.35 ) and diastolic pressure by 0.27 mm Hg ( 95 % confidence interval , 0.15 - 0.39 ) after adjustment for parental incidence of hypertension and time-dependent body mass index , cigarette smoking , alcohol drinking , and physical activity in analyses using generalized estimating equations . Compared with nondrinkers at baseline , coffee drinkers had a greater incidence of hypertension during follow-up ( 18.8 % vs. 28.3 % ; P = .03 ) . Relative risk ( 95 % confidence interval ) of hypertension associated with drinking 5 or more cups a day was 1.35 ( 0.87 - 2.08 ) for baseline intake and 1.60 ( 1.06 - 2.40 ) for intake over follow-up . After adjustment for the variables listed above , however , these associations were not statistically significant . CONCLUSION Over many years of follow-up , coffee drinking is associated with small increases in blood pressure , but appears to play a small role in the development of hypertension Selected demographic , behavioral and psychophysiological variables ( sex of the subject , exercise , coffee and cigarette consumption , baroreceptor stimulation-dependent pain dampening , initial blood pressure , body mass index , daily stress rating , reactivity to mental stress as measured by change in stress rating and heart rate and blood pressure from resting to mental arithmetic conditions ) were entered into a stepwise multiple-regression equation to predict changes of oscillometrically self-measured tonic blood pressure in 80 normotensives over a 19 month period . The prediction equation ( r = 0.55 ) associated increases in diastolic blood pressure with baseline diastolic blood pressure , more baroreceptor stimulation-dependent pain inhibition , and less heart rate change during mental arithmetic . There were no significant predictors of systolic changes , and no sex differences . Results are discussed in terms of the learned model of hypertension To assess the validity of self-reported illnesses , medical records were review ed for participants reporting major illnesses on the biennial follow-up question naires used in a prospect i ve cohort study which began in 1976 . In over 90 % of cases of cancer of the breast , skin , large bowel , and thyroid , histopathology reports confirmed the subjects ' self-report . Lower levels of confirmation were obtained for cancers of the lung , ovary , and uterus . Application of strict diagnostic criteria also gave lower levels of confirmation for myocardial infa rct ion ( 68 % ) and stroke ( 66 % ) . Among r and om sample s of women reporting fractures and hypertension all records obtained confirmed self-reports . For self-reported elevated cholesterol levels 85.7 % of self-reports were confirmed . Self-report is a valuable epidemiologic tool but may require additional documentation when the disease is diagnostically complex Objectives The longitudinal relationship between coffee use and hypertension is still controversial . Cytochrome P450 1A2 ( CYP1A2 ) is the main responsible enzyme for the metabolism of caffeine . The aim of the present study was to investigate the effect of coffee intake on the risk of developing hypertension needing antihypertensive treatment in individuals stratified by CYP1A2 genotype . Design We assessed prospect ively 553 young White individuals screened for stage 1 hypertension .  Coffee intake  was ascertained from regularly administered question naires . Incident physician-diagnosed hypertension was the outcome measure . Genotyping of CYP1A2 SNP was performed by real time PCR . Results During a median follow-up of 8.2 years , 323 individuals developed hypertension . For carriers of the slow * 1F allele ( 59 % ) , hazard ratios of hypertension from multivariable Cox analysis were 1.00 in abstainers ( reference ) , 1.72 ( 95%CI , 1.21–2.44 ) in moderate coffee drinkers ( P = 0.03 ) , and 3.00 ( 1.53–5.90 ) in heavy drinkers ( P = 0.001 ) . In contrast , hazard ratios for coffee drinkers with the rapid * 1A/*1A genotype were 0.80 ( 0.52–1.23 , P = 0.29 ) for moderate drinkers and 0.36 ( 0.14–0.89 , P = 0.026 ) for heavy drinkers . In a two-way ANCOVA , a gene × coffee interactive effect was found on follow-up changes in systolic ( P = 0.000 ) and diastolic ( P = 0.007 ) blood pressure . Urinary epinephrine was higher in coffee drinkers than abstainers but only among individuals with slow * 1F allele ( P = 0.001 ) . Conclusion These data show that the risk of hypertension associated with coffee intake varies according to CYP1A2 genotype . Carriers of slow * 1F allele are at increased risk and should thus abstain from coffee , whereas individuals with * 1A/*1A genotype can safely drink coffee BACKGROUND Data on the impact of the many dietary and lifestyle factors on the prevalence of  hypertension  in Western societies are lacking . This study quantified the contributions of body weight , physical inactivity and dietary factors to the prevalence of hypertension in Finl and , Italy , the Netherl and s , United Kingdom ( UK ) and USA . METHODS Distributions of blood pressure ( BP ) and risk factors in Western population s were obtained from nationwide surveys . The effect of risk factors on BP was assessed by meta-regression analysis of r and omized trials , published between 1966 and March 2001 . Population attributable risk percentages ( PAR% ) for hypertension ( i.e. systolic BP > or = 140 mmHg ) were computed for all risk factors in the five countries . RESULTS Being overweight made the largest contribution to hypertension , with PAR% between 11 % ( Italy ) and 25 % ( USA ) . PAR% were 5 - 13 % for physical inactivity , 9 - 17 % for high sodium intake , 4 - 17 % for low potassium intake and 4 - 8 % for low magnesium intake . The impact of alcohol was small ( 2 - 3 % ) in all population s. PAR% varied among population s for inadequate intake of calcium ( 2 - 8 % ) , magnesium ( 4 - 8 % ) , coffee ( 0 - 9 % ) and fish fatty acids ( 3 - 16 % ) . CONCLUSIONS Diet and lifestyle have a substantial impact on  hypertension  in Western societies , with being overweight , physical inactivity , high sodium intake and low potassium intake being the main contributors . The relative significance of different risk factors varies among population s , which is important for preventative strategies UNLABELLED Only three Japanese prospect i ve studies have suggested an inverse association between  coffee drinking and liver cancer risk . No prospect i ve studies on the association between serum gamma-glutamyltransferase ( GGT ) and liver cancer risk have been reported . We aim ed to determine the single and joint associations of coffee consumption and serum GGT with the risk of primary liver cancer . Study cohorts included 60,323 Finnish participants who were 25 - 74 years 
    Output:
    
The results suggest that habitual coffee consumption of > 3 cups/d was not associated with an increased risk of hypertension compared with < 1 cup/d ; however , a slightly elevated risk appeared to be associated with light-to-moderate consumption of 1 to 3 cups/d