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CMAJ
CMAJ - October 19, 1999JAMC - le 19 octobre 1999
Cardiovascular Disease in Seniors

Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986­1992

Donald B. Langille, MD, MHSc; Michel R. Joffres, MD, PhD; Kathleen M. MacPherson, MD, MPH; Pantelis Andreou, MSc; Susan A. Kirkland, PhD; David R. MacLean, MD, MHSc

CMAJ 1999;161(8 suppl):S3

Contents
Abstract

Background: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians.

Methods: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease.

Results: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected.

Interpretation: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.

Canadians are aging rapidly: by the year 2016, the proportion of the population older than 65 years of age will have increased from its current level of 12% to 16%.1 In Canada cardiovascular disease is the leading cause of death overall -- and in those over 65 years of age -- and even the decreases in age-adjusted rates of cardiovascular disease that have occurred since the late 1960s do not offset the increases in absolute numbers of cases caused by the increasing age of the population.2 Understanding the prevalence of risk factors for cardiovascular disease in older Canadians is therefore of concern to those responsible for health policy and planning. Although there are many risk factors related to cardiovascular disease in the older population,3 this paper is limited to hypertension, dyslipidemia, smoking, lack of exercise and obesity.

Of all the risk factors for cardiovascular disease, high blood pressure, especially high systolic blood pressure, is the best predictor of coronary artery disease,4,5 the incidence of which increases dramatically with age.3 Hypertension is also a leading risk factor for stroke,6,7 the incidence of which also increases rapidly with age.8,9 Factors other than hypertension may also be involved in the increase in stroke with age.10

Increased serum total cholesterol, increased low-density-lipoprotein (LDL) cholesterol and decreased high-density-lipoprotein (HDL) cholesterol are well-established risk factors for ischemic heart disease in middle age.11 However, the degree of risk of ischemic heart disease imposed by altered lipids in older people remains controversial, with some studies refuting the relation12,13,14 and others supporting it.15,16

Although it is well established that smoking is a major risk factor for ischemic heart disease in middle-aged populations,17,18 it has been argued that the risk associated with smoking diminishes with age.19,20,21 This argument has been countered by studies demonstrating that smoking in those over 64 years of age is associated with increases in ischemic heart disease22,23 and overall death from cardiovascular disease.24

Regular physical activity protects against coronary artery disease,25,26 although much of its effect may be through its influence on other risk factors, including blood pressure, lipids and body mass.27 Although the Longitudinal Study of Aging has shown that regular physical activity is beneficial for those over 70 years of age in terms of all-cause mortality,28 the effect of exercise on cardiovascular disease in the older population is less clear.29,30

The association of obesity with cardiovascular disease in younger populations is well established.31 Studies of obesity in older people are few, but obesity is linked to other cardiovascular risk factors in older people, including hypertension, altered lipids32 and diabetes.33 Data from the Cardiovascular Health Study indicated a positive association between heavier weight and cardiovascular disease in those older than 65 years, especially women.34

The current study was carried out as part of the data-gathering process of the Canadian Heart Health Initiative, which collected information concerning heart health risk from Canadians in all 10 provinces. The data presented here describe the prevalence of risk factors in those 55 to 74 years of age.

[Contents]

Methods

The general methodology followed in the provincial heart health surveys, including collection of blood and biochemical testing methods, sample design, training, quality control, and data processing and analysis, has been reported previously.35

All 10 Canadian provinces participated in the Heart Health Surveys, which took place from 1986 to 1992. Sampling in each province consisted of stratified, 2-stage, replicated probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps. Health insurance registries were used as the sampling frames.

For each participant, a trained nurse conducted a 40- to 60-minute home interview, collecting demographic and lifestyle data, as well as information on the participant's level of knowledge and awareness of the risk factors for cardiovascular disease. Participants were asked to attend a clinic within 2 weeks of the initial visit, at which time anthropometric measurements were taken and blood was drawn for analysis.

Anthropometric measurements were taken in the morning with participants dressed in light indoor clothing and no shoes. Height was measured with a tape measure affixed to a wall and a fixed square (to ensure that the marker was level on the top of the subject's head). Participants stood on a hard surface, and height was measured to the nearest centimetre. Weight was measured to the nearest 100 g by means of beam balance scales. Body mass index (BMI) was calculated as weight in kilograms/(height in metres)2.

Blood pressure readings were taken with a standard mercury­gravity manometer. A compression cuff based on arm circumference and the diaphragm side of a stethoscope with 37-cm tubing were used. Each participant had been asked not to eat or smoke for a minimum of 30 minutes before the readings were taken and rested quietly for a minimum of 5 minutes before the readings. The person's right arm was held at the level of the heart. The maximum inflation level was determined before the reading was taken. The first and fifth Korotkoff sounds were recorded for the systolic and diastolic pressures respectively; for sounds that continued to 0 mm Hg, the fourth Korotkoff sound was recorded.

A total of 4 readings were taken: at the beginning and end of the home interview and at the beginning and end of the clinic visit. Blood pressure data are based on the mean of these 4 measurements. For participants who did not come to the clinic, the values used are based on the mean of the 2 measurements taken during the home interview.

The lipid data reported here are for participants who had fasted for 8 hours or longer. All plasma lipid analyses were carried out at the J. Alick Little Lipid Research Laboratory, University of Toronto. Throughout the study period this laboratory maintained certification in part III of standardization for cholesterol, triglyceride and HDL cholesterol measurement under the National Heart, Lung, and Blood Institute, Centers for Disease Control Lipid Standardization Program.36 The cut points in the distributions of plasma lipid and lipoprotein that were used to assign risk of coronary artery disease were those derived for adults from the Canadian Consensus Conference on Cholesterol37 and the US National Cholesterol Education Program guidelines.38

To more fully understand the relation between the prevalence of risk factors and age, the data were analysed according to 2 subgroups: participants 55 to 64 years of age and those 65 to 74 years of age.

All reported measures have been weighted to account for the sampling design, and the values in the tables represent population estimates.

[Contents]

Results

Response rate

Of 3932 men and 3994 women 55 to 74 years of age who were asked to participate in the survey, 5956 (75%) did so (2981 men [76%] and 2975 women [74%]). Of these, 2739 men (92% [70% overall]) and 2617 women (88% [66% overall]) also visited the clinic. Of men attending the clinic, 904 (33%) were 55 to 64 years of age, and 1835 (67%) were 65 to 74 years of age. Of women attending the clinic, 901 (34%) were 55 to 64 years of age, and 1716 (66%) were 65 to 74 years of age.

Hypertension

When hypertension was defined as systolic blood pressure of at least 140 mm Hg or diastolic blood pressure of at least 90 mm Hg (or both) and/or treatment with blood pressure medication and/or dietary therapy (or any combination of these criteria), 54% of men and 50% of women were found to have the condition; for both sexes, hypertension was more prevalent in the older age group (Table 1). Older women had the highest prevalence of hypertension (58%). Of participants with hypertension, 52% were receiving neither dietary nor pharmacologic treatment (data not shown). When the definition of hypertension was limited to isolated elevation of systolic blood pressure, 27% of men and 26% of women had the condition (Table 2). In both sexes, isolated systolic hypertension was also more common in the older age group than in the younger age group: 34% of men and 38% of women 65 to 74 years of age had the condition.

Blood lipids

In both age groups, women had higher total blood cholesterol levels than men (Table 3). Overall, 78% of women and 60% of men had a total blood cholesterol level of 5.2 mmol/L or greater, and 38% of women and 20% of men had a total blood cholesterol level of 6.2 mmol/L or greater.

HDL cholesterol levels of less than 0.9 mmol/L were far more common in men than women. For 15% of men in both age groups the level of this form of cholesterol was less than 0.9 mmol/L, whereas only 2% of women 55 to 64 years of age and 3% of those 65 to 74 years of age had an HDL cholesterol below this level (Table 4).

Overall, more men than women had LDL cholesterol levels of less than 3.4 mmol/L (48% v. 40%). In addition, more women than men had LDL cholesterol levels of 4.1 mmol/L or greater (33% v. 20%) (Table 5).

About 25% of men in both age groups had triglyceride levels of 2.3 mmol/L or greater, whereas slightly fewer women (18% of those 55 to 64 years of age and 20% of those 65 to 74 years of age) had triglyceride measurements at this level or higher (Table 6).

Smoking

The proportion of women who had never been smokers was more than 3 times as great as the proportion of men who had never smoked. However, many men were ex-smokers (60% overall), so rates of current smoking, although lower in women than in men (17% v. 22%), were not dramatically different (Table 7). Overall, 87% of men and 78% of women who were current smokers smoked 10 or more cigarettes per day (data not shown). The proportion of men in the 2 age groups who smoked to this extent was almost equal (88% in the younger age group and 85% in the older age group), whereas fewer older women than younger women did so (74% v. 81%).

Physical activity

Slightly more than half of the participants exercised one or more times per week for more than 15 minutes (Table 8). Men in the older age group were more likely to be physically active to this degree than younger men (57% v. 49%) or than women in both younger and older age groups (53% and 51% respectively).

Body mass index

Almost half of the men and women had a BMI of 27 or more (46% and 45% respectively) (Table 9). For both sexes, the proportion of participants with a BMI above this cut point was lower in the older than in the younger age group.

Multiple risk factors

Table 10 shows the prevalence of multiple risk factors. Only 4% of participants had none of the 5 selected risk factors: hypertension (defined on the basis of blood pressure of 140/90 mm Hg or higher or treatment for hypertension), dyslipidemia (defined as total blood cholesterol of 5.2 mmol/L or greater or HDL cholesterol less than 0.9 mmol/L or LDL cholesterol 3.4 mmol/L or greater or triglycerides 2.3 mmol/L or greater), regular smoking, sedentary lifestyle or excess weight (BMI of 25 or greater). Almost half (49%) had 3 or more of these risk factors. Although the prevalence of 3 or more concurrent risk factors decreased slightly with age in men, it increased with age in women: 51% of women 65 to 74 years of age but only 43% of those 55 to 64 years of age had 3 or more of the risk factors.

[Contents]

Interpretation

This study found that significant numbers of Canadian men and women 55 to 74 years of age had risk factors for cardiovascular disease. Overall, 52% were hypertensive, 26% had isolated systolic hypertension, and 30% had levels of total blood cholesterol at which intensive dietary intervention is recommended (6.2 mmol/L or greater).37 Fifteen percent of men had an HDL cholesterol level that made them candidates for intervention (less than 0.9 mmol/L). Overall, 56% of participants had an LDL cholesterol level of 3.4 mmol/L or greater, and 21% had a triglyceride level of 2.3 mmol/L or greater, levels at which dietary intervention is recommended for adults.37 In addition, many participants had more than 1 of the 5 major risk factors for cardiovascular disease.

Hypertension, thought to be the most significant of these risk factors,4 was untreated in 52% of those in whom it was present. In both sexes, participants in the older age group were more likely to have hypertension defined on the basis of systolic blood pressure of 140 mm Hg or greater or diastolic blood pressure of 90 mm Hg or greater or drug or dietary therapy (or some combination of these criteria). Of the 26% who had isolated systolic hypertension (140 mm Hg or greater), a greater proportion were in the older age group. This pattern is typical of developed countries, where systolic blood pressure rises throughout life and declines much later than diastolic blood pressure, which generally rises until the sixth decade and then levels off or declines.39 The benefits of treating isolated systolic hypertension in elderly people, in terms of both nonfatal stroke and myocardial infarction, have been demonstrated in clinical trials,40,41 as have the benefits of treating elevated systolic and diastolic blood pressure in reducing stroke, myocardial infarction and total mortality rate.42,43 The decline in death from ischemic heart disease and stroke in the United States since the 1970s,44 including a decline in death of elderly people caused by stroke, is to a large extent attributable to better diagnosis and control of hypertension.45,46 The number of those with undiagnosed or untreated hypertension, especially the approximately 26% of both sexes with isolated systolic hypertension, is significant, especially given the extent to which Canadians are unaware of their hypertension.47

Significant proportions of participants had total blood cholesterol equal to or greater than 6.2 mmol/L, the level at which the Canadian Consensus Conference on Cholesterol recommends intervention for those over 30 years of age.37 This problem was more common in women than in men. Fewer women than men had HDL cholesterol levels below 0.9 mmol/L (3% v. 15%), but women were more likely than men to have LDL cholesterol levels equal to or greater than 3.4 mmol/L (60% v. 52%). Although the relation between total blood cholesterol and cardiovascular disease in the older population remains somewhat unclear,12,13,14,15,16 altering lipids in older people is thought by some to be effective in reducing cardiovascular disease.48 Trials of reductase inhibitors in younger people have shown that lowering lipids can reduce mortality rate.49,50 In addition, it has been argued that because the risk of death from ischemic heart disease and stroke increases with increasing age,3,8 the number of deaths attributable to cholesterol problems may be greater in absolute terms and may justify intervention.51,52

Many older Canadians continue to smoke cigarettes, despite evidence that stopping smoking can be of benefit to older people. Jajich and associates22 studied a population of 2674 men and women over the age of 65 in the United States and found that the higher risk of death from coronary artery disease among cigarette smokers was reduced to the same level as that of nonsmokers 1 to 5 years after cessation of smoking. A review of the literature concerning smoking in older adults concluded that overall risk of death was lower for ex-smokers than for current smokers within 1 to 2 years after smoking cessation and approached that of never-smokers after 15 or 20 years.53 There is also evidence that in people older than 55 years of age who have had coronary artery surgery, smoking cessation is associated with a decrease in the risk of myocardial infarction or death, with no decline in benefit with increasing age.54

Almost 50% of those taking part in this study, both men and women, reported little or no exercise. Paffenbarger and associates,25 in a study of male Harvard alumni, found that in the cohort 65 to 74 years of age, the risk of a coronary event in the least active group was twice that of the most active group. A recent study involving a US health maintenance organization found that people older than 65 years of age who walked more than 4 hours per week had a lower risk of admission to hospital for cardiovascular disease; this finding was more pronounced in women.55 Recently, it has been demonstrated that leisure time physical activity in multiethnic elderly city residents of both sexes is associated with a lower incidence of ischemic stroke.56

Clinical trials have shown that older people can undertake exercise programs successfully,57 and exercise has many benefits for older people, including delay in the onset of frailty.3 In addition, exercise may have a beneficial effect, at least in middle-aged and older men, through weight loss.27,58 Excess weight and obesity are thought to constitute an independent risk factor for cardiovascular disease59 and are linked to other cardiovascular risk factors, including high blood pressure, lipid abnormalities and diabetes.32,33 In this study, about 45% of both men and women had a BMI equal to or greater than 27, a level associated with increased risk of cardiovascular disease.59 Given the potential for weight reduction to affect other risk factors and given that obesity is so prevalent, weight control deserves high priority as a preventive measure,48 and increasing physical activity is one way to reduce this risk factor.27,58

Almost 50% of participants in this study had 3 or more major risk factors for cardiovascular disease. These risk factors are known to act synergistically rather than additively,60 which should engender increased concern over the results of this study.

[Contents]

Conclusion

The data that have been presented here indicate that many older Canadians have risk factors for cardiovascular disease, the leading cause of death in Canada. Cardiovascular disease resulted in an estimated 294 000 years of life lost in 1995, third after injuries and cancer.2 Recent analysis of secular trends in risk factor levels and improvements in treatment has demonstrated the significant impact of prevention on the decline in death from coronary artery disease.61 It has been postulated that in Western societies with relatively low death rates, prevention efforts can have a greater effect on cumulative lifetime disability (morbidity) than on mortality.62 Thus, concerted action on the risk factors for cardiovascular disease in both mid and late life can perhaps lead most importantly to a "compression" of the period of morbidity in the last years of life,63 which would result in improved quality of life for Canada's increasingly older population.64

Competing interests: None declared.

From the Department of Community Health and Epidemiology, Faculty of Medicine, Dalhousie University, Halifax, NS

This article has been peer reviewed.

This paper is published on behalf of the Canadian Heart Health Surveys Research Group and is sponsored by Health Canada.

Address reprint requests to: Dr. Donald B. Langille, Department of Community Health and Epidemiology, Faculty of Medicine, Dalhousie University, 5849 University Ave., Halifax NS B3H 4H7

Members of the Canadian Heart Health Surveys Research Group: Christofer Balram, PhD, Department of Health and Community Services, Fredericton, NB; Lynne Blair, BScN, MPA, British Columbia Ministry of Health, Victoria, BC; David Butler-Jones, MD, MHSc, Saskatchewan Health, Regina, Sask.; Roy Cameron, PhD, University of Waterloo, Waterloo, Ont.; Ruth Collins-Nakai, MD, University of Alberta, Edmonton, Alta.; Philip W. Connelly, PhD, St. Michael's Hospital and University of Toronto, Toronto, Ont.; Catherine Donovan, MD, MHSc, Memorial University of Newfoundland, St. John's, Nfld.; Ron Dyck, PhD, Alberta Health, Edmonton, Alta.; Alison C. Edwards, MSc, Memorial University of Newfoundland, St. John's, Nfld.; Dale Gelskey, MPH, DPH, University of Manitoba, Winnipeg, Man.; Kevin Hogan, MD, Memorial University of Newfoundland, St. John's, Nfld.; Michel R. Joffres, MD, PhD, Dalhousie University, Halifax, NS; Richard Lessard, MD, MPH, Public Health Directorate, Montreal, Que.; Sharon M. Macdonald, MD, University of Manitoba, Winnipeg, Man.; David R. MacLean, MD, MHSc (Chair), Dalhousie University, Halifax, NS; Ella MacLeod, RN, MSc, Prince Edward Island Heart Health Program, Charlottetown, PEI; Mukund Nargundkar, MSc, MEng (deceased), Statistics Canada, Ottawa, Ont.; Brian A. O'Connor, MD, MHSc, University of British Columbia, Vancouver, BC; Gilles Paradis, MD, MSc, McGill University, Montreal, Que.; Andres Petrasovits, PhD, MPH, Health Canada, Ottawa, Ont.; Bruce A. Reeder, MD, MHSc, University of Saskatchewan, Saskatoon, Sask.; Richard Schabas, MD, MHSc, Ontario Ministry of Health, Toronto, Ont.; Lamont Sweet, MD, MHSc, PEI Department of Health and Social Services, Charlottetown, PEI; Rosemary White, BScN, MSc, Heart and Stroke Foundation of PEI, Charlottetown, PEI.

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References
  1. Statistics Canada. Population by sex and age, estimates for 1996 and projections for 2001, 2006, 2011 and 2016. Available: www.statcan.ca/english/Pgdb/People/Population/demo23a.htm (accessed 1999 Aug 22).
  2. Heart disease and stroke in Canada. Ottawa: Statistics Canada, Health Statistics Division, Health Canada, and Heart and Stroke Foundation of Canada. 1997. p. 3.
  3. Powell C, MacKnight C. Epidemiology of heart disease. In: Pathy MJS, editor. Principles and practice of geriatric medicine. vol 1. Toronto: John Wiley & Sons; 1998. p. 517-31.
  4. Vokonas PS, Kannel WB, Cupples LA. Epidemiology and risk of hypertension in the elderly: the Framingham study. J Hypertens 1988;6:S3-9.
  5. Taylor JO, Cornoni-Huntley J, Curb JD, Manton KG, Ostfeld AM, Scherr P, et al. Blood pressure and mortality risk in the elderly. Am J Epidemiol 1991;134:489-501. [MEDLINE]
  6. Fodor JG. Hypertension control: historic perspectives -- 25 years of progress in Canada and around the world. Can J Public Health 1994;85(Suppl 2):S7-8.
  7. World Health Organization. Hypertension control: report of a WHO expert committee. WHO Tech Rep Ser 1996;862:1-83.
  8. Kawachi I. Epidemiology of stroke. Importance of preventive pharmacological strategies in elderly patients and associated costs. Drugs Aging 1994;5:288-99. [MEDLINE]
  9. Cardiovascular disease. In: Strasser T, editor. Cardiovascular care of the elderly. Geneva: World Health Organization; 1987. p. 111-7.
  10. Curb JD, Abbott RD, MacLean CJ, Rodriguez BL, Burchfiel CM, Sharp DS, et al. Age-related changes in stroke risk in men with hypertension and normal blood pressure. Stroke 1996;27:819-24. [MEDLINE]
  11. Garber AM, Browner WS, Hulley SB. Cholesterol screening in asymptomatic adults, revisited. Ann Intern Med 1996;124:518-31. [MEDLINE]
  12. Kronmal PE, Cain KC, Ye Z, Omenn GS. Total serum cholesterol and mortality risk as a function of old age. Arch Intern Med 1993;153:1065-73. [MEDLINE]
  13. Leaverton PE, Havlik RJ, Ingster-Moore IM, LaCroix AZ, Cornoni-Huntley JC. Coronary heart disease and hypertension. In: Cornoni-Huntley JC, Huntley RR, Feldman JJ, editors. Health status and well-being of the elderly. New York: Oxford University Press; 1990. p. 53-70.
  14. Krumholz HM, Seeman TE, Merrill SS, Mendes de Leon CF, Vaccinaro V, Silverman DI, et al. Lack of association between cholesterol and coronary heart disease mortality and morbidity and all-cause mortality in persons older than 70 years. JAMA 1994;272:1335-40. [MEDLINE]
  15. Rossouw JE, Mangdiwala S, Gordon DJ, Bush JL, Rifkind BL. Plasma lipids as predictors of CHD in older men and women: the LRC follow-up study [abstract]. Circulation 1990;82(Suppl 3):346.
  16. Frost PH, Davis BR, Burlando AJ, Curb JD, Guthrie GP, Isaacsohn JL, et al. Serum lipids and incidence of coronary heart disease: findings from the systolic hypertension in the elderly program (SHEP). Circulation 1996;94:2381-8. [MEDLINE]
  17. The health consequences of smoking: cardiovascular disease. A report of the Surgeon General. Department of Health and Human Services publ no. (PHS) 84-50204. Washington: US Public Health Service, Office on Smoking and Health; 1983. p. 6-8.
  18. Wilhelmson L. Coronary heart disease: epidemiology of smoking and intervention studies of smoking. Am Heart J 1988;115:242-9. [MEDLINE]
  19. Doll R, Peto R. Mortality in relation to smoking: 20 years' observations on male British doctors. BMJ 1976;2:1525-36.
  20. Harris T, Cook EF, Kannel WB, Goldman L. Proportional hazards analysis of risk factors for coronary heart disease in individuals aged 65 or older: the Framingham Heart Study. J Am Geriatr Soc 1988;36:1023-8. [MEDLINE]
  21. Castelli WP, Wilson PW, Levy D, Anderson K. Cardiovascular risk factors in the elderly. Am J Cardiol 1989;63:12H-19H.
  22. Jajich CL, Ostfeld AM, Freeman DH Jr. Smoking and coronary heart disease mortality in the elderly. JAMA 1984;252:2831-4. [MEDLINE]
  23. Benfante R, Reed D, Frank J. Does cigarette smoking have an independent effect on coronary artery disease incidence in the elderly? Am J Public Health 1991;81:897-9. [MEDLINE]
  24. LaCroix AZ, Lang J, Scherr P, Wallace RB, Cornoni-Huntley J, Berkman L, et al. Smoking and mortality among older men and women in three communities. N Engl J Med 1991;324:1619-25. [MEDLINE]
  25. Paffenbarger RS, Wing AL, Hyde RT. Physical activity as an index of heart attack risk in college alumni. Am J Epidemiol 1978;108:161-75. [MEDLINE]
  26. Morris JN, Everitt MG, Pollard R, Chave SP, Semmence AM. Vigorous exercise in leisure-time: protection against coronary heart disease. Lancet 1980;2:1207-10. [MEDLINE]
  27. Rodriguez BL, Curb JD, Burchfiel CM, Abbott RD, Petrovich H, Masaki K, et al. Physical activity and 23-year incidence of coronary heart disease morbidity and mortality among middle-aged men. The Honolulu Heart Program. Circulation 1994;89:2540-4. [MEDLINE]
  28. Rakowski W, Mor V. The association of physical activity with mortality among older adults in the Longitudinal Study of Aging (1984­1988). J Gerontol 1992;47:M122-9. [MEDLINE]
  29. Sherman SE, D'Agostino RB, Cobb JL, Kannel WB. Does exercise reduce mortality rates in the elderly? Experience from the Framingham Heart Study. Am Heart J 1994;128:965-72. [MEDLINE]
  30. Simonsick EM, Lafferty ME, Phillips CL, Mendes de Leon CF, Kasl SV, Seeman TE, et al. Risk due to inactivity in physically capable older adults. Am J Public Health 1993;83:1443-50. [MEDLINE]
  31. Pi-Sunyer FX. Health implications of obesity. Am J Clin Nutr 1991;53(6 Suppl):1595S-1603S.
  32. Burack RC, Keller JB, Higgins MW. Cardiovascular risk factors and obesity: Are baseline levels of blood pressure, glucose, cholesterol and uric acid elevated prior to weight gain? J Chron Dis 1985;38:865-72.
  33. Felber JP, Acheson KJ, Tapp L. Epidemiological aspects. In: From obesity to diabetes. West Sussex (UK): John Wiley and Sons; 1993. p. 1-14.
  34. Harris TB, Savage PJ, Tell GS, Haan M, Kumanyika S, Lynch JC. Carrying the burden of cardiovascular risk in old age: associations of weight and weight change with prevalent cardiovascular disease, risk factors, and health status in the Cardiovascular Health Study. Am J Clin Nutr 1997;66:837-44. [MEDLINE]
  35. MacLean DR, Petrasovits A, Nargundkar M, Connelly PW, MacLeod E, Edwards A, et al. Canadian Heart Health Surveys: a profile of cardiovascular risk. Survey methods and data analysis. Canadian Heart Health Surveys Research Group. CMAJ 1992;146(11):1969-74. [MEDLINE]
  36. Lipid and lipoprotein analysis. In: Manual of laboratory operation, lipid research clinics program (revised). Publ no. 75-678. Washington: US Department of Health, Education, and Welfare; 1982. p. 1-143.
  37. Canadian Consensus Conference on the Prevention of Heart and Vascular Disease by Altering Serum Cholesterol and Lipoprotein Risk Factors. Canadian Consensus Conference on Cholesterol: final report. CMAJ 1988;139(11 Suppl):1-8. [MEDLINE]
  38. Summary of the second report of the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel II). JAMA 1993;269(23):3015-23. [MEDLINE]
  39. Landahl S, Bengstson C, Sigurdsson JA, Svanborg A, Svardsudd K. Age-related changes in blood pressure. Hypertension 1986;8:1044-9. [MEDLINE]
  40. Staessen J, Fagard R, Amery A. Isolated systolic hypertension in the elderly: implications of Systolic Hypertension in the Elderly Program (SHEP) for clinical practice and for the ongoing trials. J Hum Hypertens 1991;5:469-74. [MEDLINE]
  41. SHEP Cooperative Research Group. Prevention of stroke by antihypertensive drug treatment in older persons with isolated systolic hypertension: final results of the Systolic Hypertension in the Elderly Program (SHEP). JAMA 1991;265:3255-64. [MEDLINE]
  42. Dahlof B, Lindholm LH, Hansson L, Schersten B, Ekbom T, Wester PO. Morbidity and mortality in the Swedish Trial in Old Patients with Hypertension (STOP-Hypertension). Lancet 1991;338:1281-5. [MEDLINE]
  43. MRC Working Party. Medical Research Council trial of treatment of hypertension in older adults: principal results. BMJ 1992;304:405-12. [MEDLINE]
  44. National Heart, Lung and Blood Institute. Part III: A closer look. In: Report of the Task Force on Research in Atheroschlerosis. Bethesda (MD): The Institute; 1992. p. 114-5.
  45. Barker WH, Mullooly JP. Stroke in a defined elderly population, 1967­1985: a less lethal and disabling but no less common disease. Stroke 1997;28:285-90.
  46. MacMahon S, Cutler JA, Stamler J. Antihypertensive drug treatment: potential, expected and observed effects on stroke and coronary heart disease. Hypertension 1989;13(5 Suppl):145-50. [MEDLINE]
  47. Joffres MR, Ghadirian P, Fodor JG, Petrasovits A, Chockalingam A, Hamet P. Awareness, treatment and control of hypertension in Canada. Am J Hypertension 1997;10:1097-102.
  48. Kannel WB. Cardiovascular risk factors in the elderly. Coron Artery Dis 1997;9:565-75.
  49. Shepherd J, Cobbe SM, Ford I, Isles CG, Lorimer AR, MacFarlane PW, et al. Prevention of coronary heart disease with pravastatin in men with hypercholesterolemia. West of Scotland Coronary Prevention Study Group. N Engl J Med 1995;333:1301-7. [MEDLINE]
  50. Scandinavian Simvastatin Survival Study Group. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet 1994;344:1383-9. [MEDLINE]
  51. Rubin SM, Sidney S, Black DM, Browner WS, Hulley SB, Cummings SR. High blood cholesterol in elderly men and the excess risk for coronary heart disease. Ann Intern Med 1990;113:916-20. [MEDLINE]
  52. Rose G. The relation of risk to exposure. In: The strategy of preventive medicine. Oxford: Oxford University Press; 1992. p. 15-28.
  53. LaCroix AZ, Omenn GS. Older adults and smoking. Clin Geriatr Med 1992;8:69-87. [MEDLINE]
  54. Hermanson B, Omenn GS, Kronmal RA, Gersh BJ. Beneficial six-year outcome of smoking cessation in older men and women with coronary artery disease: results from the CASS registry. N Engl J Med 1988;319:1365-9. [MEDLINE]
  55. LaCroix AZ, Leveille SG, Hecht JA, Grothaus LC, Wagner EH. Does walking decrease the risk of cardiovascular disease hospitalizations and death in older adults? J Am Geriatr Soc 1996;44:113-20. [MEDLINE]
  56. Sacco RL, Gan R, Boden-Albala B, Lin IF, Kargman DE, Hauser WA, et al. Leisure-time physical activity and ischemic stroke risk: the Northern Manhattan Stroke Study. Stroke 1998;29:380-7. [MEDLINE]
  57. Morey MC, Cowper PA, Feussner JR, DiPasquale RC, Crowley GM, Sasma GP, et al. Two-year trends in physical performance following supervised exercise among community-dwelling older veterans. J Am Geriatr Soc 1991;39:986-92. [MEDLINE]
  58. Katzel LI, Bleecker ER, Colman EG, Rogus EM, Sorkinc JD, Goldberg AP. Effects of weight loss vs aerobic exercise training on risk factors for coronary disease in healthy, obese, middle-aged and older men: a randomized controlled trial. JAMA 1995;274:1915-21. [MEDLINE]
  59. Health and Welfare Canada. Nutrition recommendations: the report of the scientific review committee. Ottawa: Minister of Supply and Services; 1990. p. 15-16.
  60. Kannel WB, Neaton JD, Wentworth D, Thomas HE, Stamler J, Hulley SB, et al. Overall and coronary heart disease mortality rates in relation to major risk factors in 325,348 men screened for the MRFIT. Multiple Risk Factor Intervention Trial. Am Heart J 1986;112:825-36. [MEDLINE]
  61. Hunink MG, Goldman L, Tosteson A, Mittleman MA, Goldman PA, Williams LW, et al. The recent decline in mortality from coronary heart disease, 1980­1990: the effect of secular trends in risk factors and treatment. JAMA 1997;277:535-42. [MEDLINE]
  62. Fries JF. Aging, natural death, and the compression of morbidity. N Engl J Med 1980;303:130-5. [MEDLINE]
  63. Vita AJ, Terry RB, Hubert HB, Fries JF. Aging, health risks, and cumulative disability. N Engl J Med 1998;338:1035-41. [MEDLINE]
  64. Campion EW. Aging better. N Engl J Med 1998;338:1064-6. [MEDLINE]