Occupational, Commuting, and Leisure-TimePhysical Activity in Relation to CardiovascularMortality Among Finnish Subjects WithHypertension

Gang Hu, Pekka Jousilahti, Riitta Antikainen, and Jaakko Tuomilehto

AJH 2007; 20:1242–1250

Background: The association between different typesof physical activity and cardiovascular risk among hyper-tensive subjects is not fully understood. The purpose ofthis study was to determine the association of occupa-tional, commuting, and leisure-time physical activity oncardiovascular mortality among hypertensive patients.

Methods: Study cohorts included 26,643 hypertensiveFinnish men and women who were aged 25 to 64 yearsand free of coronary heart disease, stroke, and Type 1diabetes.

Results: During a mean follow-up of 19.9 years (range,6.6 to 31.7 years), 3743 subjects died because of cardio-vascular disease. The multivariate-adjusted (age, studyyear, education, alcohol consumption, smoking, bodymass index, systolic blood pressure, total cholesterol, useof antihypertensive drugs, and diabetes at baseline orduring follow-up, and the other two kinds of physicalactivity) hazard ratios of cardiovascular mortality associ-ated with low, moderate, and high occupational physical

activity were 1.00, 0.84, and 0.86 (P for trend � .006),

Hospital (JT), Seinäjoki, Finland.

0895-7061/07/$32.00doi:10.1016/j.amjhyper.2007.07.015

respectively, for hypertensive men, and 1.00, 0.85, and0.84 (P for trend � .014), respectively, for hypertensivewomen. The multivariate-adjusted hazard ratios of cardio-vascular mortality associated with low, moderate, and highleisure-time physical activity were 1.00, 0.84, and 0.73(P for trend � .001), respectively, for hypertensive men,and 1.00, 0.78, and 0.76 (P for trend � .001), respectively,for hypertensive women. Active commuting to and fromwork was significantly associated with reduced cardiovas-cular mortality in hypertensive women.

Conclusions: Moderate or high levels of occupationalor leisure-time physical activity reduce cardiovascularmortality among both men and women with hypertension.Walking or cycling to and from work daily reduces car-diovascular mortality among hypertensive women. Am JHypertens 2007;20:1242–1250 © 2007 American Journalof Hypertension, Ltd.

Key Words: Exercise, cardiovascular disease, mortal-

ity, epidemiology, hypertension.

H igh blood pressure (BP) is a major worldwidepublic health problem.1 It is well-established thatBP has a positive association with risk of cardio-

vascular disease (CVD).2,3 Several4,5 but not all prospec-tive studies6 demonstrated that regular physical activity isrelated to a reduced risk of hypertension. There is strongevidence that regular leisure-time physical activity reducesCVD risk in the general population.7–10 However, data onthe association between leisure-time physical activity and

Received April 19, 2007. First decision May 25, 2007. Accepted July 29,2007.

From the Department of Health Promotion and Prevention of ChronicDiseases (GH, PJ, JT), National Public Health Institute, Helsinki; De-partment of Public Health (GH, JT), University of Helsinki, Helsinki;School of Public Health (PJ), University of Tampere, Tampere; OuluCity Hospital and Department of Public Health Science and GeneralPractice (RA), University of Oulu, Oulu; and South Ostrobothnia Central

CVD risk among people with hypertension, particularly inwomen, are sparse. Moreover, it is not clear whether otherkinds of physical activity besides leisure-time physicalactivity, such as occupational and daily commuting phys-ical activity on foot or by bicycle, may reduce CVD riskamong hypertensive subjects. The aim of this study was toexamine whether occupational, commuting, and leisure-time physical activity are independently associated withCVD mortality in hypertensive individuals.

Supported by grants 46558, 204274, 205657, and 118065 from theFinnish Academy (Helsinki, Finland), by the Finnish Foundation forCardiovascular Research (Helsinki, Finland), and by Special ResearchFunds of the Social Welfare and Health Board, City of Oulu (Oulu,Finland).

Address correspondence and reprint requests to Dr. Gang Hu, De-partment of Health Promotion and Prevention of Chronic Diseases,National Public Health Institute, Mannerheimintie 166, FIN-00300 Hel-

sinki, Finland; e-mail: hu.gang@ktl.fi

© 2007 by the American Journal of Hypertension, Ltd.Published by Elsevier Inc.

1243AJH–December 2007–VOL. 20, NO. 12 EXERCISE AND CVD DEATH IN HYPERTENSION

MethodsParticipants

Six independent population surveys were performed infive geographic areas of Finland in 1972, 1977, 1982,1987, 1992, and 1997.11 In 1972 and 1977, a randomlyselected sample comprising 6.6% of the population bornbetween 1913 and 1947 was drawn. Since 1982, the sam-ple has been stratified by area, gender, and 10-year agegroup according to the World Health Organization (WHO)Monitoring Trends and Determinants of CardiovascularDisease (MONICA) protocol.12 Subjects who participatedin more than one survey were included only in the firstsurvey cohort. The total sample size of the six surveys was52,058 participants, aged 25 to 64 years. The participationrate varied by year from 74% to 88%.11 Participants gaveinformed consent (verbal, 1972 to 1992; signed, 1997).Surveys were conducted according to the ethical rules ofthe National Public Health Institute (Helsinki, Finland),and the investigations were performed in accordance withthe Declaration of Helsinki.

Assessment of Hypertension

Participants who had systolic BP (SBP) �140 mm Hg ordiastolic BP (DBP) �90 mm Hg, or who were receivingantihypertensive drugs according to the questionnaire orwho had received an approval for special reimbursementfor antihypertensive drugs before the baseline survey,were defined as manifesting hypertension and were in-cluded in the present analysis. Moderate or severe hyper-tension was defined as SBP �160 mm Hg or DBP �95mm Hg at baseline.13 Data on the initiation of antihyper-tensive drug treatment for hypertension were receivedform the records of the Social Insurance Institution’s na-tionwide register on persons entitled to special reimburse-ment for antihypertensive drugs. In principle, everyresident in Finland was entitled to such a reimbursementfrom 1964 to 2002. To obtain an approval for it, thediagnosis of hypertension had to be assigned by the pa-tient’s own physician on the basis of the WHO or Euro-pean Society of Hypertension criteria for hypertension.13

The physician’s statement, documenting the details of thediagnosis of hypertension, was reviewed by an expertphysician at the Social Insurance Institution. Computer-ized record linkage was performed using the nationalpersonal identification number assigned to every personliving permanently in Finland. All patients receiving spe-cial reimbursement for medication for hypertension wereentered into a register maintained by the Social InsuranceInstitution. This method for the diagnosis of hypertensionwas used also in previous studies.5 Of the 29,208 eligibleparticipants with hypertension, we excluded 1399 patientswho had a history of coronary heart disease (n � 969) orstroke (n � 351) at baseline, or who had Type 1 diabetesat baseline or during follow-up (n � 79), and 1166 patientswho had incomplete data on any required study variables.

Thus, 14,399 men and 12,244 women were included in the

present study. The sample sizes of men and women in eachsurvey year were 3714 and 3404 in 1972, 3505 and 3133in 1977, 2583 and 2069 in 1982, 1630 and 1268 in 1987,1370 and 1154 in 1992, and 1597 and 1216 in 1997,respectively.

Assessment of Physical Activity

Occupational, commuting, and leisure-time physical activ-ity was assessed using a self-administered questionnaire.A detailed description of the questions was presentedelsewhere.10,14–17 Subjects reported their occupationalphysical activity according to the following three catego-ries: (1) “low” was physically very easy, such as sedentaryoffice work, eg, secretary; (2) “moderate” was work thatentailed standing and walking, eg, store assistant or lightindustrial worker; and (3) “high” was work that entailedwalking and lifting, or heavy manual labor, eg, industrialor farm work. The daily-commuting return journey wascategorized into three categories: (1) motorized transpor-tation or no work (no walking or cycling); (2) walking orbicycling 1 to 29 min per day; and (3) walking or bicycling�30 min per day. Self-reported leisure-time physical ac-tivity was classified into three categories: (1) “low” wasdefined as almost completely inactive, such as reading,watching television, or doing some minor physical activ-ity, but not of moderate or high level; (2) “moderate” wasdefined as doing some physical activity �4 h a week, suchas walking, cycling, or light gardening, excluding travel towork; and (3) “high” involved performing vigorous phys-ical activity �3 h a week, such as running, jogging,swimming, or heavy gardening, or competitive sports sev-eral times a week.

Other Assessments

Smoking, socioeconomic factors, alcohol consumption,and medical history were also assessed through the self-administered questionnaire. Based on questionnaire data,participants were classified as never smokers, ex-smokers,and current-smokers. Years of education were divided intobirth cohort-specific tertiles. Because different questionsabout alcohol consumption were asked between the firsttwo surveys (1972 and 1977) and the later surveys, par-ticipants were categorized into abstainers and alcohol us-ers. Data on diabetes were based on self-report at baselineand on data from two nationwide registers both at baselineand during follow-up. The National Hospital DischargeRegister data include hospital discharge diagnoses from1968 to 2002. Data on diabetes medication were ascer-tained from the National Social Insurance Institution’sregister on special reimbursement for antidiabetic drugsfrom 1964 to 2002 basically using the same methodologydescribed above for hypertension.5,14,15 Subjects who re-ported having diabetes in the questionnaire, or who had ahospital discharge with a diagnosis of diabetes, or ap-proval for free-of-charge medication for diabetes before

the baseline survey, were classified as having a history of

1244 AJH–December 2007–VOL. 20, NO. 12EXERCISE AND CVD DEATH IN HYPERTENSION

diabetes at baseline. Subjects who had a first hospitaldischarge diagnosis with diabetes, or a date for the ap-proval for free-of-charge medication for diabetes after thebaseline survey, were classified as having incident diabe-tes during follow-up.

At the study site, specially trained research nursesmeasured height, weight, and BP using a standardizedprotocol.12 Height was measured without shoes, andweight was measured with subjects dressed in light cloth-ing. Body mass index (BMI) was calculated as weight inkilograms divided by the square of the height in meters.Blood pressure was measured once using a standard mer-cury sphygmomanometer from the right arm of subject,who had rested 5 min in sitting position. The fifth-phaseKorotkoff sound was recorded as DBP. Serum total cho-lesterol had been determined by using the Lieberman-Burchard method in 1972 and 1977, and an enzymaticmethod (CHOD-PAP, Boehringer Mannheim, Mannheim,Germany) since 1982. Because the enzymatic methodgave 2.4% lower values than the Lieberman-Burchardmethod, 1972 and 1977 values were corrected by thispercentage. All samples were analyzed in the same centrallaboratory at the National Public Health Institute.

Prospective Follow-Up

Mortality data were obtained from Statistics Finland andwere linked with the survey data through personal identi-fication numbers. Deaths occurring outside Finland werealso registered. Dates of emigrations were obtained fromStatistics Finland. The overall sensitivity of the diagnosisof myocardial infarction in the Causes of Death Registerwas �92%.18 The International Classification of Diseases(ICD) 8th, 9th, and 10th revisions were used for coding thecauses of death. The ICD codes 390 through 459 and I00through I99 were classified as CVD deaths. The studysurveys were followed to the end of 2003, emigration, ordeath.

Statistical Analyses

Differences in risk factors by different levels of physicalactivity and by CVD death status were tested by ANOVAafter adjustment for age and study year. The associationbetween physical activity at baseline and the risk of CVDmortality was analyzed by using Cox proportional hazardsregression models. Categories of physical activity wereincluded in the models as dummy and categorical vari-ables, and the significance of a trend over different cate-gories of physical activity was tested in the same modelsby giving an ordinal numeric value for each dummy vari-able. The proportional hazards assumption in the Coxmodel was assessed with graphic methods, and with mod-els including time-by-covariate interactions.19 In general,all proportionality assumptions were appropriate. Theanalyses were first performed adjusting for age and studyyear, and then for education, alcohol consumption, smok-

ing, BMI, SBP, total cholesterol, use of antihypertensive

drugs at baseline or during follow-up, diabetes at baselineor during follow-up, and the other two kinds of physicalactivity. To avoid potential bias because of severe diseasesat baseline, additional analyses were performed, excludingsubjects who died during the first 2 years of follow-up.Statistical significance was set at P � .05. The statisticalpackage SPSS for Windows, version 15.0 (SPSS, Inc.,Chicago, IL), was used for statistical analyses.

ResultsDuring a mean follow-up of 19.9 years (range, 6.6 to 31.7years), we ascertained 3743 deaths because of CVD (2240men and 1503 women). General characteristics of thestudy population at baseline are presented in Table 1.Comparing hypertensive men and women with noncases,hypertensive men and women who died during follow-upwere older and had higher levels of major CVD riskfactors (Table 2). Age-adjusted correlations were 0.25 inhypertensive men (P � .001) and 0.24 in hypertensivewomen (P � .001) between occupational and commutingphysical activity, �0.07 in hypertensive men (P � .001)and �0.05 in hypertensive women (P � .001) betweenoccupational and leisure-time physical activity, and 0.04in hypertensive men (P � .001) and 0.08 in hypertensivewomen (P � .001) between commuting and leisure-timephysical activity.

The multivariate-adjusted (age, study year, education,alcohol consumption, smoking, BMI, SBP, total choles-terol, use of antihypertensive drugs, diabetes, and othertwo kinds of physical activity) hazard ratios (HRs) ofCVD mortality associated with low, moderate, and highoccupational physical activity were 1.00, 0.84, and 0.86(P for trend � .006), respectively, for hypertensive men,and 1.00, 0.85, and 0.84 (P for trend � .014), respectively,for hypertensive women (Table 3). When we excludedindividuals who died during the first 2 years of follow-up(n � 231), these inverse associations were still statisticallysignificant among men (P for trend � .005) and women(P for trend � .020) (data not shown).

Daily walking or cycling to and from work was signif-icantly and inversely associated with the risk of CVDmortality among hypertensive men (P for trend � .001)and women (P for trend � .001) after adjustment for ageand study year. The inverse relationship remained signif-icant among women (P for trend � .016) but not amongmen (P for trend � .607) after additional adjustment forother risk factors. When we excluded subjects who diedduring the first 2 years of follow-up, the multivariate-adjusted HRs of CVD mortality in hypertensive womenassociated with no minutes, 1 to 29 min, and �30 min ofwalking or cycling to and from work were 1.00, 0.83, and0.87 (P for trend � .022), respectively.

The multivariate-adjusted HRs of CVD mortality asso-ciated with low, moderate, and high leisure-time physicalactivity were 1.00, 0.84, and 0.73 (P for trend � .001),

respectively, for hypertensive men, and 1.00, 0.78, and

Table 1. General characteristics according to occupational, commuting, and leisure-time physical activity among study subjects with hypertensionby sex

No. ofSubjects METs

Age (y)(SE)

BodyMassIndex

(kg/m2)(SE)

SystolicBlood

Pressure(mm Hg)

(SE)

DiastolicBlood

Pressure(mm Hg)

(SE)

TotalCholesterol

(mg/dL)(SE)

Education(y) (SE)

AlcoholDrinker

(%)

CurrentSmoker

(%)

History ofDiabetes at

Baseline(%)

IncidentDiabetesDuring

Follow-Up(%)

MenOccupational

physical activityLow 5046 1.5 47.8 (0.2) 27.1 (0.1) 152 (0.2) 94 (0.2) 244 (0.7) 9.5 (0.1) 66.2 44.4 3.0 7.7Moderate 3073 2.5 42.9 (0.2) 27.0 (0.1) 151 (0.3) 93 (0.2) 243 (0.8) 9.9 (0.1) 71.4 37.9 2.2 7.8High 6280 �3 43.7 (0.1) 26.7 (0.1) 152 (0.2) 93 (0.1) 250 (0.6) 7.6 (0.1) 62.7 43.4 1.4 7.8P for trend �.001 �.001 .038 �.001 �.001 �.001 �.001 �.001 �.001 .948

Walking or cycling toand from work

0 min/day 7279 0 45.8 (0.1) 27.0 (0.1) 152 (0.2) 93 (0.1) 247 (0.5) 8.5 (0.1) 65.1 44.7 2.3 8.31–29 min/day 4513 3.5 43.0 (0.2) 26.8 (0.1) 151 (0.2) 93 (0.2) 246 (0.7) 9.2 (0.1) 66.9 39.9 1.9 7.2�30 min/day 2607 3.5 46.1 (0.2) 26.6 (0.1) 152 (0.3) 93 (0.2) 246 (0.9) 8.6 (0.1) 65.7 41.2 1.9 7.4P for trend �.001 �.001 .004 .790 .560 �.001 .138 �.001 .247 .087

Leisure-timephysical activity

Low 4297 1.5 45.8 (0.2) 27.1 (0.1) 153 (0.2) 94 (0.2) 249 (0.7) 8.3 (0.1) 62.9 50.4 2.7 10.1Moderate 7689 2.5–4.0 45.7 (0.1) 27.0 (0.1) 152 (0.2) 93 (0.1) 248 (0.5) 8.7 (0.4) 66.8 43.0 2.0 7.3High 2413 �6.0 41.1 (0.2) 26.1 (0.1) 151 (0.3) 92 (0.2) 237 (0.9) 9.8 (0.1) 67.8 27.5 1.4 5.1P for trend �.001 �.001 �.001 �.001 �.001 �.001 �.001 �.001 .002 �.001

WomenOccupational

physical activityLow 5200 1.5 51.0 (0.1) 27.8 (0.1) 155 (0.3) 93 (0.1) 250 (0.7) 8.3 (0.1) 28.0 13.8 3.7 10.3Moderate 3444 2.5 47.0 (0.2) 27.2 (0.1) 154 (0.3) 93 (0.2) 249 (0.8) 8.9 (0.1) 32.2 13.5 2.1 8.3High 3600 �3 47.8 (0.2) 28.0 (0.1) 157 (0.3) 93 (0.2) 256 (0.8) 7.4 (0.1) 20.9 9.1 1.5 10.2P for trend �.001 �.001 �.001 .542 �.001 �.001 �.001 �.001 �.001 .003

Walking or cycling toand from work

0 min/day 5986 0 50.9 (0.1) 28.2 (0.1) 156 (0.2) 93 (0.1) 253 (0.6) 7.8 (0.1) 23.5 11.8 3.5 10.91–29 min/day 3534 3.5 46.6 (0.2) 27.3 (0.1) 155 (0.3) 93 (0.2) 250 (0.8) 8.8 (0.1) 31.9 13.2 2.1 8.6�30 min/day 2724 3.5 47.7 (0.2) 27.2 (0.1) 155 (0.3) 92 (0.2) 252 (0.9) 8.6 (0.1) 28.8 12.2 1.1 8.6P for trend �.001 �.001 �.001 .366 .018 �.001 �.001 .144 �.001 �.001

Leisure-timephysical activity

Low 5309 1.5 49.9 (0.1) 28.6 (0.1) 156 (0.3) 93 (0.1) 253 (0.6) 7.8 (0.1) 25.1 14.3 3.1 11.4Moderate 5781 2.5–4.0 48.7 (0.1) 27.2 (0.1) 155 (0.2) 92 (0.1) 251 (0.6) 8.5 (0.1) 28.3 11.2 2.3 8.4High 1154 �6.0 45.8 (0.3) 26.4 (0.1) 154 (0.5) 92 (0.1) 249 (1.4) 9.0 (0.1) 30.9 8.3 1.6 8.2P for trend �.001 �.001 �.001 �.001 .053 �.001 .001 �.001 .004 �.001

Adjusted for age and study year.METs � metabolic equivalents.

12

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1246 AJH–December 2007–VOL. 20, NO. 12EXERCISE AND CVD DEATH IN HYPERTENSION

0.76 (P for trend � .001), respectively, for hypertensivewomen. After excluding individuals who died during thefirst 2 years of follow-up, these inverse associations re-mained statistically significant among both hypertensivemen and women (both P values for trend � .001). Whenfurther pooled analyses were performed based on the firsttwo surveys (1972 and 1977) and the later surveys (1982,1987, 1992, and 1997), the protective effects of differentkinds of physical activity did not change in these twodifferent periods (data not shown).

When analyses were restricted to individuals with mod-erate or severe hypertension, whose SBP was �160 mmHg or whose DBP was �95 mm Hg (n � 12,986), themultivariate-adjusted inverse associations of occupationaland leisure-time physical activity with the risk of CVDmortality were statistically significant, and the HRs werefairly similar among those whose BP was �140/90 mmHg (Table 4). Further restriction of analyses to individualswhose BP was �160/95 mm Hg at baseline, and who didnot use antihypertensive drugs at baseline (n � 9952),affected the results only slightly (Table 4). When werestricted the analyses to individuals whose BP was�160/95 mm Hg, and who used no antihypertensive drugsat baseline or during follow-up (n � 5957), the results didnot appreciably change (data not shown). The exclusion ofindividuals who died during the first 2 years of follow-updid not affect the results significantly.

The joint effects of different types of physical activityon CVD mortality are presented in Fig. 1. We dichoto-mized the level of occupational and leisure-time physicalactivity at low versus moderate to high, and the level ofcommuting physical activity at any versus none. Men andwomen with high levels of all three types of physical

Table 2. General characteristics according to cahypertension by sex

Men

Noncase(n � 12,159)

Case(n � 224

Age (y) (SE) 43.5 (0.1) 52.5 (0.Body mass index

(kg/m2) (SE) 26.8 (0.03) 27.3 (0.Systolic blood pressure

(mm Hg) (SE) 151 (0.1) 156 (0.Diastolic blood pressure

(mm Hg) (SE) 93 (0.1) 95 (0.Total cholesterol

(mg/dL) (SE) 244 (0.4) 258 (1.Education (y) (SE) 8.8 (0.03) 8.4 (0.Alcohol drinker (%) 66.5 62.2Current smoker (%) 40.6 53.6History of diabetes at

baseline (%) 1.7 4.6Incident diabetes during

follow-up (%) 7.1 11.5

Adjusted for age and study year.

activity had 36% and 39% lower multivariate-adjusted

risks of CVD mortality, compared with the least activemen and women.

DiscussionModerate or high levels of physical activity at work orduring leisure time were associated with a reduced risk ofCVD mortality in both hypertensive men and women.Walking or cycling to and from work daily was associatedwith a decreased CVD mortality among hypertensivewomen. These protective effects were also consistent insubjects with moderate or severe hypertension, and amongthose with no antihypertensive drug treatment.

High BP was found to be one of the most importantdeterminants of CVD risk in all ethnic groups.2,3,20 Thereis good evidence that regular physical activity reduces therisk of CVD in the general population.7–10 However, theeffect of physical activity on CVD mortality among hy-pertensive adults is not fully understood. We found thatonly two prospective studies evaluated the association ofphysical activity with CVD mortality among hypertensivemen,21,22 and no studies included hypertensive women. Inan early study that included 819 hypertensive Universityof Pennsylvania male alumni, those who reported no vig-orous sports play were at only slightly higher risk ofall-cause mortality than those who participated in anyvigorous sports play.21 In a Swedish study of 173 hyper-tensive men, vigorous activity was associated with a re-duced relative risk of all-cause and CVD mortality.22

There were several limitations in these two studies: (1)small sample sizes and few deaths;22 (2) the inclusion ofunhealthy subjects only, and especially patients with ahistory of myocardial infraction or stroke, which may

vascular death status among study subjects with

P Value

Women

P ValueNoncase

(n � 10,741)Case

(n � 1503)

�.001 47.9 (0.1) 56.5 (0.2) �.001

�.001 27.6 (0.05) 28.7 (0.1) �.001

�.001 155 (0.2) 163 (0.5) �.001

�.001 92 (0.1) 96 (0.3) �.001

�.001 251 (0.5) 157 (1.3) �.001�.001 8.3 (0.03) 7.7 (0.1) �.001�.001 28.8 15.2 �.001�.001 11.6 17.7 �.001

�.001 1.9 7.6 �.001

�.001 8.0 22.0 �.001

rdio

0)

2)

1)

4)

2)

0)1)

cause a potential bias because these patients may have

1247AJH–December 2007–VOL. 20, NO. 12 EXERCISE AND CVD DEATH IN HYPERTENSION

been physically inactive due to various diseases;21 (3) thelack of accounting for hypertensive medication;21,22 and(4) adjustment only for a limited number of confoundingfactors.21,22 Our study, with a large sample size (n �26,643), subjects free of CVD and Type 1 diabetes, andthe largest number of CVD deaths (n � 3743) duringfollow-up reported thus far, provides strong evidence forthe benefits of leisure-time physical activity in the preven-tion of CVD mortality in hypertension men and women.Moreover, the protective effect of leisure-time physical

Table 3. Hazard ratios of cardiovascular mortality aand leisure-time physical activity among subjects wi

No. ofCases Person-Years

MenOccupational physical

activityLow 861 82,570Moderate 371 62,646High 1008 130,615P for trend

Walking or cycling to andfrom work

0 min/day 1132 128,1761–29 min/day 600 92,479�30 min/day 508 55,177P for trend

Leisure-time physicalactivity

Low 867 82,002Moderate 1183 146,960High 190 46,870P for trend

WomenOccupational physical

activityLow 760 97,054Moderate 311 75,103High 432 82,547P for trend

Walking or cycling to andfrom work

0 min/day 946 119,5591–29 min/day 295 75,585�30 min/day 262 59,560P for trend

Leisure-time physicalactivity

Low 892 116,255Moderate 538 114,827High 73 23,622P for trend

* Adjusted for age, study year, education, alcohol consumption, santihypertensive drugs at baseline or during follow-up, and inciden

† Adjusted for age, study year, education, alcohol consumptionantihypertensive drugs at baseline or during follow-up, incident diactivity.

activity was also found among subjects who had moderate

or severe hypertension (�160/95 mm Hg) and who usedno antihypertensive drugs at baseline or during follow-up.

We found no previous studies that examined the asso-ciation between occupational or commuting physical ac-tivity and the risk of CVD mortality among hypertensivepatients. Only a few studies assessed the association be-tween occupational physical activity and the risk of totalor CVD mortality among the general population since the1990s, but the results are controversial.15,23,24 The evi-dence from our group and from one Danish study indicates

rding to different levels of occupational, commuting,ypertension

Hazard Ratios (95% Confidence Intervals)

justment fore and Study

YearMultivariableAdjustment*

MultivariableAdjustment†

1.00 1.00 1.001 (0.63–0.80) 0.82 (0.72–0.93) 0.84 (0.74–0.96)2 (0.74–0.90) 0.87 (0.78–0.96) 0.86 (0.78–0.96)

�.001 .001 .006

1.00 1.00 1.002 (0.74–0.91) 0.90 (0.81–0.99) 0.95 (0.85–1.05)4 (0.76–0.94) 0.91 (0.82–1.01) 0.98 (0.87–1.10)

�.001 .081 .607

1.00 1.00 1.008 (0.72–0.86) 0.84 (0.77–0.91) 0.84 (0.77–0.92)7 (0.49–0.67) 0.73 (0.62–0.86) 0.73 (0.62–0.86)

�.001 �.001 �.001

1.00 1.00 1.008 (0.60–0.78) 0.79 (0.69–0.90) 0.85 (0.74–0.98)5 (0.67–0.85) 0.80 (0.71–0.91) 0.84 (0.73–0.96)

�.001 �.001 .014

1.00 1.00 1.002 (0.63–0.82) 0.78 (0.68–0.89) 0.83 (0.72–0.96)0 (0.61–0.80) 0.80 (0.70–0.92) 0.86 (0.74–0.99)

�.001 �.001 .016

1.00 1.00 1.002 (0.64–0.80) 0.78 (0.70–0.87) 0.78 (0.70–0.87)0 (0.47–0.77) 0.74 (0.58–0.94) 0.76 (0.60–0.97)

�.001 �.001 �.001

ng, body mass index, systolic blood pressure, cholesterol, use ofetes at baseline or during follow-up.king, body mass index, systolic blood pressure, cholesterol, use ofs at baseline or during follow-up, and other two kinds of physical

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that moderate or higher levels of occupational physical

1248 AJH–December 2007–VOL. 20, NO. 12EXERCISE AND CVD DEATH IN HYPERTENSION

activity reduce total and CVD mortality among the generalpopulation and diabetic patients,15,24 whereas anotherstudy did not find such an association.23 Occupationalphysical activity has been largely ignored in epidemiolog-ical surveys. Active daily commuting is another majorsource of total physical activity in some populations, suchas China and Finland,10,14–16,25,26 and it was indirectlymeasured by asking for the frequency and duration ofwalking or cycling in many Western studies. Regularwalking or cycling to and from work is related to lowerlevels of cardiovascular risk factors14,25,27 and a reducedrisk of Type 2 diabetes,14 stroke,16 coronary heart dis-ease,10 and mortality among the general population anddiabetic patients.15,24 The present study is, to our knowl-edge, the first to find a protective effect of occupationalphysical activity among both hypertensive men andwomen, and of activity based on daily walking or cyclingto and from work among hypertensive women, in theprevention of CVD mortality. We cannot explain why nodose-response relationship in occupational and commutingphysical activity on CVD mortality was seen, and furtherstudies are needed to evaluate this aspect.

The protective effect of physical activity may be partlymediated by its effect on other CVD risk factors. Physicalactivity has a favorable effect on BP, lipid profile, insulin

Table 4. Hazard ratios of cardiovascular mortality aand leisure-time physical activity among subjects wi

Hazard R

Moderate or Severe Hy

Men(n � 7032) (n

Occupational physicalactivity

Low 1.00Moderate 0.81 (0.69–0.96) 0.83High 0.84 (0.74–0.96) 0.78P for trend .011

Walking or cycling toand from work,min/day

0 1.001–29 0.95 (0.84–1.09) 0.84�30 0.96 (0.84–1.11) 0.93P for trend .762

Leisure-time physicalactivity

Low 1.00Moderate 0.85 (0.76–0.95) 0.76High 0.71 (0.58–0.88) 0.71P for trend .001

* Moderate or severe hypertension was defined as systolic blood pr† Adjusted for age, study year, education, alcohol consumption

antihypertensive drugs at baseline or during follow-up, incident diactivity.

sensitivity, body weight, blood coagulation, and fibrino-

lysis.5,14,25,27,28 It is also associated with a reduced risk ofdeveloping hypertension, Type 2 diabetes, and metabolicsyndrome.5,14,29,30 In our study, the inverse associationsbetween physical activity and CVD mortality persistedafter controlling for major CVD risk factors. We alsofound that hypertensive patients who developed incidentdiabetes or started antihypertensive drug treatment duringfollow-up were lower among active versus nonactive pa-tients (data not shown).

There are several limitations in our study. The firstinvolves the self-report of physical activity; moreover,physical activity was recorded only once, at baseline.Although no direct assessment of the repeatability orvalidity of our questionnaire has been performed, sim-ilar questionnaires were successfully used in a largenumber of studies in Finland and other Nordic coun-tries.5,10,14 –16,24 We do not have data on possiblechanges in physical activity during follow-up. Misclas-sification, and particularly the over-reporting ofamounts of physical activity at baseline and changes inactivity during follow-up, would probably lead to anunderestimation of the association between physicalactivity and outcomes. Hypertension was defined basedon a single BP measurement. Because our data allowedfor only a dichotomized measure of alcohol consump-

rding to different levels of occupational, commuting,oderate or severe hypertension*

s (95% Confidence Intervals)†

tension

Moderate or Severe HypertensionWithout Antihypertensive Drug

Treatment

en954)

Men(n � 5736)

Women(n � 4216)

00 1.00 1.000–0.98) 0.88 (0.73–1.06) 0.76 (0.61–0.96)7–0.92) 0.86 (0.74–0.99) 0.77 (0.63–0.95)

006 .116 .018

00 1.00 1.001–0.99) 0.90 (0.78–1.05) 0.76 (0.61–0.95)8–1.10) 0.92 (0.78–1.08) 0.99 (0.80–1.23)

122 .377 .045

00 1.00 1.006–0.86) 0.82 (0.72–0.94) 0.77 (0.64–0.91)3–0.97) 0.71 (0.56–0.91) 0.62 (0.41–0.93)

001 .002 .002

re �160 mm Hg or diastolic blood pressure �95 mm Hg.king, body mass index, systolic blood pressure, cholesterol, use ofs at baseline or during follow-up, and other two kinds of physical

ccoth m

atio

per

Wom� 5

1.(0.7(0.6

.

1.(0.7(0.7

.

1.(0.6(0.5�.

essu, smoabete

tion in our samples, we may not have been able to

tensioof agrou

1249AJH–December 2007–VOL. 20, NO. 12 EXERCISE AND CVD DEATH IN HYPERTENSION

control fully for the effect of alcohol consumption onthe risk of CVD mortality. Finally, we cannot com-

No >=1 minute

N

1.00

0.70*0.77*0.75*

0

0,2

0,4

0,6

0,8

1

HR

ofC

VD

mor

talit

y

Commuting PALeisure-time PA

Low

ModeraLow

No >=1 minute

N

1.00

0.67*0.74*

0.60*

0

0,2

0,4

0,6

0,8

1

HR

ofC

VD

mor

talit

y

Commuting PALeisure-time PA

Low

ModeraLow

A

B

FIG. 1. Hazard ratios (HRs) of cardiovascular (CVD) mortality acphysical activity (PA) among men (A) and women (B) with hypersmoking, body mass index, systolic blood pressure, cholesterol, usediabetes at baseline or during follow-up. *P � .05 versus reference

pletely rule out the effects of residual confounding due

to measurement error in the assessment of confoundingfactors, or some unmeasured factors, or selection bias in

>=1 minute

Moderate or active

Light

0.72*0.73*

*0.64*

Occupat

ional PA

highModerate or high

>=1 minute

Moderate or active

Light

0.66*

0.53** 0.61*

Occupat

ional PA

highModerate or high

ing to joint effects of occupational, commuting, and leisure-timen. Adjusted for age, study year, education, alcohol consumption,

ntihypertensive drugs at baseline or during follow-up, and incidentp.

o

0.64

te or

o

0.57

te or

cord

our analyses.

1250 AJH–December 2007–VOL. 20, NO. 12EXERCISE AND CVD DEATH IN HYPERTENSION

In conclusion, the present study demonstrates that mod-erate or higher levels of occupational or leisure-time phys-ical activity can reduce the risk of CVD mortality amongboth hypertensive men and women. Walking or cycling toand from work daily seems to reduce CVD mortalityamong hypertensive women.

References

1. Antikainen RL, Moltchanov VA, Chukwuma C Sr, Kuulasmaa KA,Marques-Vidal PM, Sans S, Wilhelmsen L, Tuomilehto JO: Trendsin the prevalence, awareness, treatment and control of hypertension:the WHO MONICA Project. Eur J Cardiovasc Prev Rehabil 2006;13:13–29.

2. Lewington S, Clarke R, Qizilbash N, Peto R, Collins R: Age-specific relevance of usual blood pressure to vascular mortality: ameta-analysis of individual data for one million adults in 61 pro-spective studies. Lancet 2002;360:1903–1913.

3. Hu G, Sarti C, Jousilahti P, Peltonen M, Qiao Q, Antikainen R,Tuomilehto J: The impact of history of hypertension and Type 2diabetes at baseline on the incidence of stroke and stroke mortality.Stroke 2005;36:2538–2543.

4. Blair SN, Goodyear NN, Gibbons LW, Cooper KH: Physical fitnessand incidence of hypertension in healthy normotensive men andwomen. JAMA 1984;252:487–490.

5. Hu G, Barengo NC, Tuomilehto J, Lakka TA, Nissinen A, JousilahtiP: Relationship of physical activity and body mass index to the riskof hypertension: a prospective study in Finland. Hypertension 2004;43:25–30.

6. Pereira MA, Folsom AR, McGovern PG, Carpenter M, Arnett DK,Liao D, Szklo M, Hutchinson RG: Physical activity and incidenthypertension in black and white adults: the Atherosclerosis Risk inCommunities Study. Prev Med 1999;28:304–312.

7. Blair SN, Cheng Y, Holder JS: Is physical activity or physicalfitness more important in defining health benefits? Med Sci SportsExerc 2001;33(Suppl):S379–S399.

8. Wannamethee SG, Shaper AG: Physical activity in the prevention ofcardiovascular disease: an epidemiological perspective. Sports Med2001;31:101–114.

9. Hu FB, Willett WC, Li T, Stampfer MJ, Colditz GA, Manson JE:Adiposity as compared with physical activity in predicting mortalityamong women. N Engl J Med 2004;351:2694–2703.

10. Hu G, Tuomilehto J, Borodulin K, Jousilahti P: The joint associa-tions of occupational, commuting, and leisure-time physical activ-ity, and the Framingham risk score on the 10-year risk of coronaryheart disease. Eur Heart J 2007;28:492–498.

11. Vartiainen E, Jousilahti P, Alfthan G, Sundvall J, Pietinen P, PuskaP: Cardiovascular risk factor changes in Finland, 1972–1997. Int JEpidemiol 2000;29:49–56.

12. WHO MONICA Project Principal Investigators: The World HealthOrganization MONICA Project (Monitoring Trends and Determi-nants in Cardiovascular Disease): a major international collabora-tion. J Clin Epidemiol 1988;41:105–114.

13. World Health Organization, International Society of HypertensionWriting Group: 2003 European Society of Hypertension-EuropeanSociety of Cardiology guidelines for the management of arterialhypertension. J Hypertens 2003;21:1011–1053.

14. Hu G, Qiao Q, Silventoinen K, Eriksson JG, Jousilahti P, LindstromJ, Valle TT, Nissinen A, Tuomilehto J: Occupational, commuting,

and leisure-time physical activity in relation to risk for Type 2

diabetes in middle-aged Finnish men and women. Diabetologia2003;46:322–329.

15. Hu G, Eriksson J, Barengo NC, Lakka TA, Valle TT, Nissinen A,Jousilahti P, Tuomilehto J: Occupational, commuting, and leisure-time physical activity in relation to total and cardiovascular mortal-ity among Finnish subjects with Type 2 diabetes. Circulation 2004;110:666–673.

16. Hu G, Sarti C, Jousilahti P, Silventoinen K, Barengo NC, Tuom-ilehto J: Leisure time, occupational, and commuting physical activ-ity and the risk of stroke. Stroke 2005;36:1994–1999.

17. Hu G, Tuomilehto J, Silventoinen K, Barengo NC, Peltonen M,Jousilahti P: The effects of physical activity and body mass index oncardiovascular, cancer and all-cause mortality among 47 212 mid-dle-aged Finnish men and women. Int J Obes 2005;29:894–902.

18. Pajunen P, Koukkunen H, Ketonen M, Jerkkola T, Immonen-RaihaP, Karja-Koskenkari P, Mahonen M, Niemela M, Kuulasmaa K,Palomaki P, Mustonen J, Lehtonen A, Arstila M, Vuorenmaa T,Lehto S, Miettinen H, Torppa J, Tuomilehto J, Kesaniemi YA,Pyorala K, Salomaa V: The validity of the Finnish Hospital Dis-charge Register and Causes of Death Register data on coronary heartdisease. Eur J Cardiovasc Prev Rehabil 2005;12:132–137.

19. Cox DR: Regression models and life tables (with discussion). J RStat Soc B 1972;34:187–220.

20. Yusuf S, Hawken S, Ounpuu S, Dans T, Avezum A, Lanas F,McQueen M, Budaj A, Pais P, Varigos J, Lisheng L: Effect ofpotentially modifiable risk factors associated with myocardial in-farction in 52 countries (the INTERHEART Study): case-controlstudy. Lancet 2004;364:937–952.

21. Paffenbarger RS Jr, Jung DL, Leung RW, Hyde RT: Physicalactivity and hypertension: an epidemiological view. Ann Med 1991;23:319–327.

22. Engstrom G, Hedblad B, Janzon L: Hypertensive men who exerciseregularly have lower rate of cardiovascular mortality. J Hypertens1999;17:737–742.

23. Folsom AR, Arnett DK, Hutchinson RG, Liao F, Clegg LX, CooperLS: Physical activity and incidence of coronary heart disease inmiddle-aged women and men. Med Sci Sports Exerc 1997;29:901–909.

24. Andersen LB, Schnohr P, Schroll M, Hein HO: All-cause mortalityassociated with physical activity during leisure time, work, sports,and cycling to work. Arch Intern Med 2000;160:1621–1628.

25. Hu G, Pekkarinen H, Hanninen O, Yu Z, Guo Z, Tian H: Commut-ing, leisure-time physical activity, and cardiovascular risk factors inChina. Med Sci Sports Exerc 2002;34:234–238.

26. Hu G, Pekkarinen H, Hanninen O, Yu Z, Tian H, Guo Z, NissinenA: Physical activity during leisure and commuting in Tianjin, China.Bull WHO 2002;80:933–938.

27. Hu G, Pekkarinen H, Hanninen O, Tian H, Guo Z: Relation betweencommuting, leisure time physical activity and serum lipids in aChinese urban population. Ann Hum Biol 2001;28:412–421.

28. Mayer-Davis EJ, D’Agostino R Jr, Karter AJ, Haffner SM, RewersMJ, Saad M, Bergman RN: Intensity and amount of physical activityin relation to insulin sensitivity: the Insulin Resistance Atheroscle-rosis Study. JAMA 1998;279:669–674.

29. Laaksonen DE, Lakka HM, Salonen JT, Niskanen LK, Rauramaa R,Lakka TA: Low levels of leisure-time physical activity and cardio-respiratory fitness predict development of the metabolic syndrome.Diabetes Care 2002;25:1612–1618.

30. Hu G, Lindstrom J, Valle TT, Eriksson JG, Jousilahti P, Silvento-inen K, Qiao Q, Tuomilehto J: Physical activity, body mass index,and risk of Type 2 diabetes in patients with normal or impaired

glucose regulation. Arch Intern Med 2004;164:892–896.