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GAINING WEIGHT INCREASES THE RISK FORTHE DEVELOPMENT OF HEART FAILUREDespite the fact that the death rate from coronaryheart disease has decreased 60% over the past 40years, the age-adjusted risk for developing conges-tive heart failure has continued to increase. Overthis same time period, the risk of becoming obesehas increased at epidemic proportions, affectingmore than one third of Americans over 20 years ofage. It has been unclear whether obesity is an inde-pendent risk factor for developing heart failure orwhether this association is a result of other condi-tions, such as hypertension, dyslipidemia, or dia-betes, which are so often found in obese subjects.Although this observation has been well studied atthe extremes of obesity (body mass index [BMI]>40), the impact of having lesser degrees of obesi-ty (BMI >30) or of being overweight (BMI 25–30)has remained unclear.

In the first major community-based study toinvestigate the risk of weight gain and the develop-ment of heart failure, investigators from theFramingham Heart Study studied 5881 men andwomen (mean age, 55 years; 5% women) with noevidence of heart failure at baseline. Beginning in1976, over an average follow-up of 14 years, heartfailure developed in 8% of the cohort. After adjust-ing for other risk factors known to be associatedwith the development of heart failure, i.e., smok-ing, high cholesterol, diabetes, and hypertension, itwas noted that in people who were obese (BMI>30) there was a two-fold increase in the risk ofheart failure. The risk of heart failure independent-ly increased 5% for men and 7% for women foreach unit increase in BMI >25. Those who wereoverweight but not obese (BMI 25–29.9) had a riskthat was intermediate between the risk in normal-weight and obese subjects. Being obese (BMI >30)

was independently responsible for 11% of theheart failure cases in men and 14% of the casesthat occurred in women. Increased BMI remains asignificant risk factor for developing heart failure.Strategies to promote ideal body weight mayreduce this risk.—Kenchaiah S, Evans J, Levy D, etal. Obesity and the risk of heart failure. N Engl JMed. 2002;347:305–313.

CommentHeart failure remains a major health problem associ-ated with substantial morbidity and mortality. Thisobservational analysis from the Framingham HeartStudy suggests that a BMI ≥25 in both men andwomen may result in heart failure, and the risk ofheart failure continues to increase with increasing lev-els of BMI. Although the precise mechanism(s)accounting for this causation is unclear, the authorssuggest that there is experimental evidence associatingweight gain with an increase in hemodynamic load,neurohormonal activation, increased oxidative stress,and cardiac steatosis associated with lipoapoptosis.

It is unclear whether or not the findings in this pre-dominantly white sample can be generalized to otherraces and ethnic groups who are more likely to becomeobese. Black women continue to remain at greatest riskfor obesity. Beginning at age 28, black men becameobese 2.2-times faster than white men. Hispanic menand women are also more likely to develop obesitythan their white counterparts. These groups also needto be studied for the association of weight gain andheart failure risk.

Americans are becoming obese at epidemic pro-portions with an estimated 61% of Americansages 20–74 either overweight or obese. With obe-sity occurring at an earlier age, the early identifi-cation of individuals at risk for obesity may betterprepare us to develop strategies that more effec-tively focus on those at greatest risk of developingheart failure. Intervention strategies to preventobesity should target all ethnic groups at youngerages when they remain at highest risk for becom-ing obese. Obesity must not remain the No. 1untreated disease in this country.

A n a l y s i s o f R e c e n t P a p e r s i n H y p e r t e n s i o nJ a n B a s i l e , M D , S e c t i o n E d i t o r

Jan Basile, MD

From the Ralph H. Johnson VA Medical Center,Medical University of South Carolina, Charleston, SCAddress for correspondence:Jan Basile, MD, Ralph H. Johnson VA Medical Center,1090 Bee Street, Charleston, SC 29403

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COFFEE INTAKE OVER 33 YEARS IS NOT ASSOCIATED WITH DEVELOPING HYPERTENSIONDrinking coffee acutely raises blood pressure; as aresult it has been recommended that blood pressurenot be taken within thirty minutes of coffee ingestion.Adaptation to the acute cardiovascular effects of cof-fee occurs promptly, with blood pressure quicklyreturning to baseline. However, whether chronic cof-fee ingestion increases the long-term risk of developinghypertension has never been studied.

As part of the Johns Hopkins Precursors Study, aprospective longitudinal study of former Hopkinsmedical students, the long-term effect of coffee drink-ing on the development of hypertension was assessed.Excluding women, because of the small number ofgraduates, 1017 normotensive white men (mean age26 years) graduating between 1948 and 1964 sup-plied coffee information while in medical school.Through an annual questionnaire, caffeinated coffeeintake was assessed at baseline by self-report rangingfrom zero to more than five cups of coffee. This ques-tionnaire was repeated at least every 5 years, up to 11times during follow-up.

Over a median of 33 years, 281 men developedhypertension at a median age of 53 years. Each cup ofcoffee per day was associated with a 0.21 mm Hghigher systolic and 0.26 mm Hg higher diastolic bloodpressure. During follow-up, Cox analysis (adjusted forcigarettes smoked, alcohol intake, physical activity,and body mass index) found no association betweencoffee drinking and the development of hypertension.

Although coffee drinking is associated with smallincreases in blood pressure, the authors concludedthat over many years of follow-up it plays a small rolein the development of hypertension.—Klag M, WangNY, Meoni L, et al. Coffee intake and risk of hyper-tension. Arch Intern Med. 2002;162:657–662.

CommentThe risks of coffee drinking and increased blood pres-sure have been pondered for many years. Although arecent meta-analysis of up to 1 years’ duration foundthat coffee drinkers had slightly raised blood pressureswhen compared to nondrinkers, no prospective studieson coffee consumption and the risk of developinghypertension have been previously performed. In thisprospective longitudinal study of former medical stu-dents, the ability to repeatedly measure coffee intakefrom young adulthood to age 60 as well as receive val-idated self-reports of developing hypertension, provid-ed a unique opportunity to study this question.

Drinking one cup of coffee was associated withsmall increases in blood pressure. However, after

adjusting for a number of factors associated withhypertension, long term coffee drinking was not asso-ciated with the risk of developing hypertension.Continued adaptation over the long period of follow-up may explain why the effect on systolic blood pres-sure is less than that seen in previous clinical trials.While coffee consumption may acutely raise bloodpressure, studies have not found an increase in the riskof hemorrhagic stroke, a marker of uncontrolledhypertension, and coffee drinking.

Weaknesses of the study include those that arewell known to occur in a format that uses a self-reported questionnaire, the fact that it is generalize-able only to white men of high socioeconomic sta-tus, and the fact that the amount of other dietaryfactors associated with hypertension, such as sodi-um, potassium, and fiber intake, were not known.

Despite the fact that cessation of coffee con-sumption in those with hypertension has beenassociated with reduction in blood pressure, drink-ing caffeinated coffee does not appear to play amajor role in the incidence of hypertension.

SERIAL HEMODYNAMIC MEASUREMENTSALLOW BETTER BLOOD PRESSURE CONTROL THAN CLINICAL JUDGMENT INTHOSE WITH REFRACTORY HYPERTENSIONWhile effective control of blood pressure lowersboth stroke and cardiovascular mortality, only onein four hypertensive adult Americans have theirblood pressure controlled to <140/90 mm Hg. Asmany as 13% of patients are referred to hyperten-sion clinics for “resistant hypertension,” i.e., ablood pressure >140/90 mm Hg on three or moreantihypertensive medications, one of which is adiuretic. The term is often used interchangeablywith “refractory hypertension,” which refers to theinability to control blood pressure to <140/90 mmHg with the use of two or more agents.

Investigators from the Mayo Clinic in Rochester,MN compared the use of serial noninvasive hemo-dynamic measurements (HD) with care deliveredconventionally by a clinical hypertension specialist(SC) in an effort to improve the blood pressure con-trol rates in those with refractory hypertension. Overa 30-month period, 104 patients (mean age 66; 48%male) with refractory hypertension were randomlyassigned to a 3-month treatment period comparingHD with SC. Using thoracic bioimpedance, aninstrument that detects changes in thoracic fluid vol-ume during systole, real-time measurements ofstroke volume were determined which, when cou-pled with heart rate and blood pressure measure-ments, can determine cardiac output and systemic

vascular resistance. HD measurements were obtainedin both groups at the initiation and end of the studybut remained unavailable to the SC group. In addi-tion, monthly measurements were taken for the HDgroup. Subjects in the HD group, based on the meas-urements made, were treated according to a prede-fined treatment algorithm with the selection andtitration of antihypertensive medication made by asingle physician.

With the average subject receiving 3.6 different med-ications at entry (range of 2–6 medications), includinga diuretic in 91%, there were no differences in age, gen-der distribution, blood pressure, or renal functionbetween treatment groups. While a secondary cause ofhypertension was identified in 34% of subjects, theywere equally distributed between treatment groups andtreated medically until the end of the study period.

Blood pressure was favorably lowered by intensi-fied drug therapy in both groups (169/87 to 139/72mm Hg in the HD group compared to 173/91 to147/79 mm Hg in the SC group). Achieved bloodpressure levels were lower, however, for the HDgroup than the SC group (56% vs. 33% controlledto 140/90 mm Hg, respectively). While the finalnumber of medications, total number of daily doses,and the number of office visits did not differ be-tween the groups, the defined daily dose of diureticwas higher in the HD group.

The results demonstrate that better blood pressurecontrol may occur over a 3-month treatment period byusing hemodynamic measurements and a treatmentalgorithm compared to clinical judgment by a hyper-tension specialist. Measurements of thoracic fluid vol-ume suggest occult volume expansion and the need forincreasing diuretic use as the reason for differencesbetween groups in blood pressure control.—Taler SJ,Textor SC, Augustine JE. Resistant hypertension: com-paring hemodynamic measurement to specialist care.Hypertension. 2002;39:982–988.

CommentAdequate control of blood pressure continues toelude the majority of practitioners caring for thosewith hypertension. Refractory hypertension, affect-ing only a minority of hypertensive patients, isassociated with a disproportionately high risk ofcardiovascular events. Despite the availability ofmore effective antihypertensive agents than everbefore, refractory hypertension continues to posemanagement problems for the clinician. The use ofnoninvasive measurements to guide therapeuticdecisions has been limited by the reproducibility ofthe results, cost, and the lack of improvement inoutcome over clinically-based therapy.

In this short-term 3-month study, 56% ofpatients randomized to HD and 33% of thoseassigned to care under a clinical hypertension spe-cialist had blood pressure controlled to <140/90mm Hg. The better results using HD care at thefinal visit resulted from detection of higher periph-eral resistance associated with volume expansionand the greater use of diuretic therapy to controlblood pressure. As patients in both groups requiredthe same number of medications (four or more),and similar number of clinic visits, better bloodpressure control was a result of more changes inmedication choices and treatment intensity in theHD care group.

Occult volume expansion often limits effectiveblood pressure control. HD care appeared toimprove blood pressure control to a greater degreethan specialist care in those with refractory hyper-tension. However, larger trials of longer durationusing bioelectrical impedance at baseline will be nec-essary before hemodynamic-based care becomesready for prime time. For now, in those with refrac-tory hypertension, more frequent use of and largerdoses of diuretics appear to be important in improv-ing blood pressure control.

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