Is Worrying Bad for Your Heart?
A Prospective Study of Worry and Coronary Heart Disease in the Normative Aging Study
Background Worry is an important component of anxiety, which recent work suggests is related to increased incidence of coronary heart disease (CHD). Chronic worry has also been associated with decreased heart rate variability. We hypothesized that high levels of worry may increase CHD risk.
Method and Results We examined prospectively the relationship of worry with CHD incidence in the Normative Aging Study, an ongoing cohort of older men. In 1975, 1759 men free of diagnosed CHD completed a Worries Scale, indicating the extent to which they worried about each of five worry domains: social conditions, health, financial, self-definition, and aging. During 20 years of follow-up, 323 cases of incident CHD occurred: 113 cases of nonfatal myocardial infarction (MI); 86 cases of fatal CHD; and 124 cases of angina pectoris. Worry about social conditions was the domain most strongly associated with incident CHD. Compared with men reporting the lowest levels of social conditions worry, men reporting the highest levels had multivariate adjusted relative risks of 2.41 (95% CI, 1.40 to 4.13) for nonfatal MI and 1.48 (95% CI, 0.99 to 2.20) for total CHD (nonfatal MI and fatal CHD). A dose-response relation was found between level of worry and both nonfatal MI (P for trend, .002) and total CHD (P for trend, .04).
Conclusions These results suggest that high levels of worry in specific domains may increase the risk of CHD in older men.
Recent research has suggested that anxiety is related to incidence of coronary heart disease (CHD).1 2 3 4 In the Normative Aging Study (NAS), men who reported two or more anxiety symptoms (assessed using items from the Cornell Medical Index) had an adjusted relative risk (RR) of fatal CHD of 1.94 (95% CI, 0.70 to 5.41) and an adjusted RR of sudden cardiac death of 4.46 (95% CI, 0.92 to 21.6).2 Using the Crown-Crisp index (a measure of phobic anxiety), a prospective examination of anxiety and CHD risk in the Health Professionals Follow-up Study1 found the RR of fatal CHD among men with the highest anxiety levels was 2.45 (95% CI, 1.00 to 5.96) compared with men reporting no anxiety symptoms. The psychological and biological mechanisms by which anxiety is related to CHD are not yet clearly understood. A greater understanding of the psychological process of anxiety may thus shed further light on its relationship with CHD. Psychologists have suggested that emotions are comprised of at least three components−cognitive, expressive-behavioral, and neurobiological−and have identified worry as related to the cognitive component of anxiety.5 6 7 For example, individuals who are chronic and extreme “worriers” fit into the DSM-III-R (Diagnostic and Statistical Manual of Mental Disorder) category of generalized anxiety disorder.8 9 Anxiety and worry, however, have been found to be separate but related processes independently associated with other psychological processes like constructive problem solving or depression10 ; a better understanding of the relationship between cardiovascular health and anxiety may be obtained by examining some of its component processes separately. Psychological research suggests that worry may function as a coping mechanism, as an attempt to control unwanted experiences (future catastrophes, perceived threats). The coping mechanism (worry), however, can itself become an unwanted experience that is difficult to control.8 Worrying can be a constructive process10 ; when problem-solving strategies are thwarted by personality or situational factors, however, worrying may have negative effects, including negative cognitions, defining problems as catastrophes, and increased anxiety and/or depression levels.10 Some researchers have hypothesized that the negative cognitions and perceived lack of control associated with ineffective problem solving have deleterious consequences for health,11 although these consequences have never been empirically examined.
In the present study, we provided a test of the hypothesis that chronic worrying is related to risk of CHD, using the NAS, an ongoing cohort of older community-dwelling men.
The NAS is a longitudinal study of aging established by the Veterans Administration in 1961.12 The study cohort consists of 2280 community-dwelling men from the greater Boston area aged 21 to 80 years at the time of entry. Volunteers were screened at entry according to health criteria12 and were free of known chronic medical conditions at the start of follow-up. Because men with known chronic conditions were excluded from the original cohort, the study cohort comprised healthy individuals.
Assessment of Worry
Worry has been defined as negative affect, associated with a perceived inability to control or obtain desired results in upcoming situations.9 Many worry assessments are content-based; the division of worries into spheres or domains is a central feature of this type of measurement.13 In 1975, a survey assessing health and psychological well-being was administered by mail to all active cohort members (n=2011). The worries scale was administered as part of the assessment of psychological well-being and included 20 items asking participants to rate on a scale of 1 (never) to 5 (all the time) how much they worry about various issues. Using these scale ratings, we quantified how much subjects worry and their worry level about a particular content domain.13 For example, an average score of 2 on the health worry subscale suggests that the individual was not highly worried and that his health was not a particular concern (similar to rating “no” if asked about health concerns on a yes/no scale). The present scale, similar to other reliable and validated worry scales,13 was designed to analyze worry content. A principal components analysis with a varimax rotation14 identified five worry domains within the 20 items: worry about social conditions (eg, economic recession); health (eg, dying); finances (eg, money shortages); self-definition (eg, religious faith); and aging (eg, senility) (see “Appendix”). All subscales had high internal consistency reliability (α coefficients ranging from 0.73 to 0.82) with the sole exception of the financial worry scale (α=0.38). However, we retained the financial worry scale, since it explained 7.5% of the variance in the overall scale. High scores on each subscale of the worries scale suggest high levels of worry about that particular domain. Similar worry scales have been found to correlate highly with various measures of trait anxiety (SCL-90, Spielberger Trait Anxiety, MAACL) and depression (BDI).15 16 17
Responses to each scale item were summed, and a mean score for each worry subscale was obtained. For each subscale, the scores were then categorized a priori into three levels based on the distribution of scores in this population. We also analyzed each worry subscale as a continuous variable.
Measurement of Other Cardiovascular Risk Factors
Every 3 to 5 years, participants in the NAS are assessed by physical examination, updating of medical history, and measurement of a variety of biochemical values including serum cholesterol. Cigarette smoking status (current, former, never) is ascertained by a trained interviewer. Current smokers are defined as men who smoke ≥1 cigarette per day. Weight and height are measured with the participants wearing only socks and underpants. Body mass index (weight/height2) is then calculated. Blood pressure is measured by an examining physician using a standard mercury sphygmomanometer with a 14-cm cuff. With the subject seated, systolic blood pressure and fifth-phase diastolic blood pressures are measured in each arm to the nearest 2 mm Hg. The average of systolic and diastolic blood pressures in each arm was used in analyses.
Assessment of Morbidity and Mortality
This study includes all confirmed CHD end points that occurred between the return of the 1975 survey and April 1995. The diagnostic categories of CHD include nonfatal myocardial infarction (MI), angina pectoris, total CHD (nonfatal MI plus fatal CHD), and combined angina pectoris and total CHD (nonfatal MI, angina pectoris, and fatal CHD). The criteria for MI and angina pectoris were those used in the Framingham Heart Study.18 MI was diagnosed only when documented by unequivocal ECG changes (ie, pathological Q waves), by a diagnostic elevation of serum enzymes (serum glutamic-oxalacetic transaminase and lactic dehydrogenase) together with chest discomfort consistent with MI, or by autopsy. The diagnosis of angina pectoris was made by a board-certified cardiologist (P.V.) on the basis of medical history and physical examination, using Framingham Heart Study criteria.18 Angina was diagnosed when a subject reported recurrent chest discomfort lasting ≥15 minutes, was distinctly related to exertion or excitement, and was relieved by rest or nitroglycerin.18 Death from CHD was designated when a death certificate (coded according to the Eighth Revision of the International Classification of Diseases19 ) indicated an underlying cause of death coded to rubric 410-414. The medical records in each instance of MI or CHD death were reviewed by a board-certified cardiologist (P.V.) to ensure accurate coding.
We performed logistic regression using the Statistical Analysis System20 to estimate age-adjusted odds ratios of CHD according to worry levels. We also performed multivariate logistic regression analysis, controlling for a range of potential confounding variables ascertained in 1975, including: age (years); body mass index (kg/m2); smoking status (never, former, current); systolic and diastolic blood pressures (mm Hg); serum cholesterol (mg/dL); family history of CHD (yes/no); and whether participant drank two or more drinks of alcohol per day (yes/no).
The 1975 survey was mailed to 2011 men; 1811 responded to the survey, and of these men, 52 were excluded because of preexisting CHD (angina pectoris or history of MI). Thus, the study population in the present report comprised 1759 men in the NAS free of diagnosed CHD in 1975 and who completed the worries survey. Thus, the worry measure was obtained prospectively, ie, before the onset of CHD.
We gave particular attention to the subscale measuring social conditions worry because this scale had the highest internal consistency reliability (α=0.82).
A total of 1758 subjects completed the social conditions subscale of the worries survey. The mean score on the social conditions subscale was 2.69 (SD, 77; range, 1.00 to 5.00). The distribution of responses to this scale in the entire cohort is shown in the Figure⇓: 31.7% of the cohort scored between 1.00 and 2.25, 50.4% scored 2.50 to 3.00, and 17.9% scored 3.25 to 5.00. There were some differences in the distribution of coronary risk factors by level of social conditions worry (Table 1⇓). Individuals who scored high were more likely to be current smokers, to drink at least two drinks of alcohol per day, and to report a slightly higher family history of heart disease. Mean age, systolic and diastolic blood pressure, serum cholesterol level, and body mass index were similar across groups. We adjusted for all variables shown in Table 1⇓ in multiple logistic regression analyses.
Of the 1758 men, 323 developed CHD over the follow-up period. The average length of follow-up was 13.7 years. There were 113 incident cases of nonfatal MI; 86 cases of fatal CHD; and 124 cases of angina pectoris. The category total CHD (n=323) included cases of nonfatal MI and fatal CHD. The category combined angina and total CHD (n=199) included cases of nonfatal MI, fatal CHD, and angina pectoris.
Increased risk of MI was associated with higher levels of worry about social conditions. Compared with men who reported never or rarely worrying about social conditions (scoring ≤2.25), those scoring between 2.5 and 3.0 had an age-adjusted RR of MI of 1.70 (95% CI, 1.01 to 2.86), while those scoring 3.25 or more had an age-adjusted RR of 2.54 (95% CI, 1.49 to 4.31; multivariate P for linear trend=.002). Adjustment for potential confounders did not materially affect these estimates (Table 2⇓).
Social conditions worry was not associated with increased risk of angina pectoris or fatal CHD (see Table 2⇑). Few cases of sudden death occurred across the tertiles of social conditions; when we estimated RRs of social conditions worry for sudden and nonsudden cardiac death separately, we found no relationship for either outcome. When end points were combined (nonfatal MI and fatal CHD), the highest level of worrying about social conditions was associated with an ≈50% excess risk of total CHD (multivariate P for linear trend=.04). Social conditions worry was also analyzed as a continuous variable. These analyses confirmed the findings described above: a one-point increase in the worry score was associated with a 50% increased risk of MI (RR=1.49; 95% CI, 1.16 to 1.93) and a 20% increased risk of total CHD (RR=1.23; 95% CI, 1.01 to 1.50) (Table 3⇓).
We also examined relationships of the four other worry domains to risk of CHD. Mean scores were 2.16 (SD=.66; range, 1 to 5) among 1745 respondents to the health worry subscale; 2.06 (SD=.67; range, 1 to 5) among 1716 respondents to the financial worry subscale; 1.77 (SD=.75; range, 1 to 5) among 1725 respondents to the self-definition worry subscale; and 1.47 (SD=.49; range, 1 to 5) among 1751 respondents to the aging worry subscale (numbers varied according to how many items on the overall worry scale were completed). Some associations were evident between the health and financial worries subscales and CHD (Table 4⇓). A one-point increase in the health worry score was associated with a modest increase in risk of angina pectoris (age-adjusted RR=1.39; 95% CI, 1.05 to 1.84). A one-point increase in the financial worry score was associated with an ≈20% excess risk for combined CHD and angina (age-adjusted RR=1.24; 95% CI, 1.04 to 1.49). These relationships did not change substantially when accounting for multiple risk factors (see Table 4⇓). Self-definition and aging worry domains were not associated with any type of CHD (Table 4⇓). We also estimated RRs of worry in each domain for sudden and nonsudden cardiac death separately. A one-point increase in the health worry score was associated with an age-adjusted RR of 2.19 for sudden cardiac death (95% CI, 1.01 to 4.76). The number of events, however, is small (n=14), and the association could have arisen by chance because of the multiple comparisons performed. No other associations were found between worry in each domain and sudden and nonsudden cardiac death.
We examined the relationship of the total worry score (all worry items combined) with all types of CHD. Total worry was associated with total CHD and with angina pectoris. A one-point increase in this scale was associated with an age-adjusted RR of 1.40 (95% CI, 1.07 to 1.83) for total CHD, and this was not substantially different after accounting for multiple risk factors. A one-point increase in this scale was also associated with an age-adjusted RR of 1.52 (95% CI, 1.02 to 2.29) for angina pectoris, which did not change substantially after taking into account multiple risk factors. No other associations with total worry were found. Because worry about social conditions may be qualitatively different from worry in the other domains, we also estimated the RR of CHD for a worry score obtained by combining all worry items except those in the social conditions worry subscale. Similar to above, a one-point increase in this scale was associated with an age-adjusted RR of 1.50 (95% CI, 1.01 to 2.21) for angina pectoris, which did not change substantially after taking into account multiple risk factors. This association was largely driven by the association between health worry and angina noted in Table 4⇑. Associations of this scale with other types of CHD were not found. Because no association was found between this scale and total CHD, it is likely that the association described earlier between total worry and total CHD is driven by the association between social conditions worry and total CHD. Finally, we examined the relationship between each worries scale and total mortality in this cohort. No significant associations were found (Table⇑s 2, 3, and 4).
We calculated the intercorrelations among the worries subscales. Social conditions worry was moderately correlated with aging and financial worries and strongly correlated with health worry (Table 5⇓).
These prospective data suggest that worry in different domains is associated with increased risk of CHD. In particular, worry about social conditions is associated with a 2-fold increase in risk of MI and with a 1.5-fold increase in risk of total CHD. Despite the strong association with risk of nonfatal MI, social conditions worry was not associated with increased risk of fatal CHD. The lack of association between worry and fatal CHD may have occurred through chance, due to the smaller number of events in this category. Worry in few other domains was associated with CHD (excepting of health worry and increased risk of angina, and increased risk of sudden cardiac death; and financial worry and increased risk of combined CHD and angina). The latter associations may have arisen through chance, given the multiple comparisons involved. The association of health worry and sudden death is of note and to our knowledge has not been described previously. While it may have been due to chance, the strength of the association suggests that it is worthy of further investigation.
To our knowledge, these are the first prospective data to suggest an association between worry (related to the cognitive component of anxiety) and risk of CHD. The association appears to be somewhat specific to distinctive domains of worry, in particular, global worry about social conditions, and to a lesser extent health and financial worries. However, further studies are needed to confirm these associations. Recent epidemiological research has increasingly focused explicitly on the relationship between specific emotions (anger, anxiety, depression) and risk of CHD, though much of this work has been done in the context of psychopathology (eg, phobic anxiety).1 4 21 This emerging literature suggests that emotions may have long-term consequences for cardiovascular health and raises questions about possible consequences of the presence of even “normal” levels of negative emotion (ie, nonpathological). Recent epidemiological research also suggests that different emotions may affect risk of coronary heart disease in specific ways. For example, in the NAS,2 anxiety symptoms were associated with risk for fatal CHD (in particular, sudden cardiac death), while a prospective examination of anger found increased risks of total CHD and angina pectoris.22 As a component of different emotion processes, worry may add to or interact with aspects of emotion that are particularly important for cardiovascular health. For example, individuals who worry more may be particularly vulnerable to emotionally stressful situations, which may act as an acute trigger of a cardiovascular event. Unfortunately, we were not able to examine this question, since no information was available on potential triggering factors. Additionally, the case-crossover study rather than the prospective cohort study is the most appropriate design for investigating triggering of CHD.23 Further exploration is needed of both the psychological and biological mechanisms whereby different emotions can influence CHD.
The intercorrelations between the worries subscales suggest that while they are related, these worry domains are substantively different from one another, which may also explain why we found few associations between a total worry score and CHD outcomes. Individuals who worry about one domain may be somewhat more likely to worry about other issues, but it is not an invariant relationship. Perceived controllability of a problem may influence the effect of worry; a sense of control has been identified as both an individual difference trait24 and as a determinant of emotion and may be importantly related to health and other outcomes.9 25 Relative to the health, financial, self-definition, and aging domains in which individuals may feel they have some control over the future, events related to general social conditions may feel less controllable. For this reason, worry in different domains may have different effects. Worry in a domain over which one has control may mobilize a constructive response (ie, going to the doctor if one experiences chest pain), whereas worry in a domain over which one has less control may prompt feelings of helplessness. However, we cannot exclude the possibility that high levels of worry in any domain have similar cardiovascular health consequences. Because higher levels of worry may occur in domains perceived to be particularly difficult to control, worry in these domains may appear to have the greatest consequences in terms of CHD outcomes.10 For example, in our data, the average worry level in all domains other than social conditions was less than 2.5. In other populations with high levels of worry in other domains (eg, aging), results may differ.
Worry also has behavioral consequences relevant to health. Our data suggest that men with higher levels of social conditions worry were more likely to smoke, have at least 2 drinks of alcohol per day, and report a family history of CHD. A family history of CHD may suggest a genetic predisposition, learned behaviors deleterious for cardiovascular health, or both. These behavioral findings are in accord with other studies, which have also found that highly worried individuals were more likely to engage in high risk behaviors (smoking, overeating, drinking).11
Recently, an independent line of research has found that chronic worriers exhibit a restricted range of variability in autonomic responses to environmental challenges.17 26 In one study,27 individuals with generalized anxiety disorder (GAD; chronic worriers) were compared with non-GAD individuals. Mean successive difference of heart rate interbeat interval was measured during rest, a 4-minute period of aversive imagery, and a 4-minute period of worry about that topic. GAD subjects exhibited little variability throughout the experiment, whereas non-GAD subjects showed a significant reduction in variability from rest to aversive imagery and a further reduction from imagery to worrisome thinking. Research is under way to confirm these findings. If confirmed, these findings suggest that reduced heart rate variability (which in turn reflects altered sympathovagal balance in the autonomic regulation of the heart) may be another mechanism by which worry increases CHD risk.28 29 30
Our decision to examine the relation between worries and CHD was based on prior epidemiological evidence of the association of anxiety to CHD risk and psychological evidence of the association of anxiety to worry. These findings are in accord with research that has found relationships between specific emotional states and disease and suggest that emotional processes may be key factors linking psychosocial factors to disease.6 The findings of the present study, however, pertain to white men and thus cannot be generalized to women or to nonwhite populations. The prospective nature of the data collection decreases the possibility of recall or information bias.
These data suggest that at high levels, the psychological process of worry may be a risk factor for CHD in older men. These findings are provocative and suggest the importance of examining a broader scope of psychosocial factors than has previously been considered, in relation to CHD risk.
This study was supported by grants HL-45089 and AG-02287 and by the Health Services Research and Development Service of the Department of Veterans Affairs. Dr Sparrow is an Associate Research Career Scientist of the Medical Research Service of the Department of Veterans Affairs. Dr Kawachi is supported by a Career Development Award from the National Heart, Lung, and Blood Institute.
- Received June 27, 1996.
- Revision received September 27, 1996.
- Accepted October 7, 1996.
- Copyright © 1997 by American Heart Association
Kawachi I, Colditz GA, Ascherio A, Rimm EB, Giovannucci E, Stampfer MJ, Willett WC. Prospective study of phobic anxiety and risk of coronary heart disease in men. Circulation. 1994;89:1992-1997.
Kawachi I, Sparrow D, Vokonas P, Weiss S. Symptoms of anxiety and risk of coronary heart disease. Circulation. 1994;90:2225-2229.
Hayward C. Psychiatric illness and cardiovascular disease risk. Epidemiol Rev. 1995;17:129-138.
Leventhal H, Patrick-Miller L. Emotion and illness: the mind is in the body. In: Lewis M, Haviland JM, eds. Handbook of Emotions. New York, NY: Guilford Press; 1993.
Roemer L, Borkovec TD. Worry: unwanted cognitive activity that controls unwanted somatic experience. In: Wegner DM, Pennebaker JW, eds. Handbook of Mental Control. Englewood Cliffs, NJ: Prentice Hall; 1993.
Barlow DH. Anxiety and Its Disorders. New York, NY: Guilford Press; 1988:235-285.
Davey GCL. Pathological worrying as exacerbated problem-solving. In: Davey G, Tallis F, eds. Worrying: Perspectives on Theory, Assessment, and Treatment. New York, NY: John Wiley & Sons; 1994:35-61.
Tallis F, Davey GCL, Capuzzo N. The phenomenology of non-pathological worry: a preliminary investigation. In: Davey G, Tallis F, eds. Worrying: Perspectives on Theory, Assessment, and Treatment. New York, NY: John Wiley & Sons; 1994:62-89.
Bell B, Rose CL, Damon A. The Normative Aging Study: an interdisciplinary and longitudinal study of health and aging. Int J Aging Hum Dev. 1972;3:5-17.
Tallis F, Davey GCL, Bond A. The worry domains questionnaire. In: Davey G, Tallis F, eds. Worrying: Perspectives on Theory, Assessment, and Treatment. New York, NY: John Wiley & Sons; 1994:285-299.
Kim JO, Mueller CW. Introduction to Factor Analysis: What It Is and How to Do It. Beverly Hills, Calif: Sage; 1978.
Powers CB, Wisocki PA, Whitbourne SK. Age differences and correlates of worrying in young and elderly adults. Gerontologist. 1992;32:82-88.
Pruzinsky T, Borkovec TD. Cognitive Characteristics of Chronic Worriers (1983), cited in Barlow DH. Anxiety and Its Disorders. New York, NY: Guilford Press; 1988:235-285.
Borkovec TD. The nature, functions, and origins of worry. In: Davey G, Tallis F, eds. Worrying: Perspectives on Theory, Assessment, and Treatment. New York, NY: John Wiley & Sons; 1994:5-34.
Shurtleff D. Some Characteristics Related to the Incidence of Cardiovascular Disease and Death: Framingham Study, 18-year Follow-up. Bethesda, Md: 1974. US Dept of Health, Education, and Welfare publication NIH 74-599.
Department of Health, Education and Welfare. International Classification of Diseases Adapted for Use in the United States, Eighth Revision. Washington, DC. 1963. US Dept of Health, Education, and Welfare PHS publication 1693.
SAS/STAT User's Guide. Version 6, 4th ed. Cary, NC: SAS Institute Inc; 1990.
Barefoot JC, Grant-Dahlstrom G, Williams RB. Hostility, CHD incidence, and total mortality: a 25-year follow-up study of 255 physicians. Psychosom Med. 1983;45:59-63.
Kawachi I, Sparrow D, Spiro A, Vokonas P, Weiss ST. A prospective study of anger and coronary heart disease: the Normative Aging Study. Circulation. 1996;94:2090-2095.
Mittleman MA, Maclure M, Sherwood JB, Mulry RP, Tofler GH, Jacobs SC, Friedman R, Benson H, Muller JE. Triggering of acute myocardial infarction onset by episodes of anger. Circulation. 1995;92:1720-1725.
Rotter JB. Generalized expectancies for internal and external control of reinforcement. Psychological Monographs 80. 1966.
Lyonsfield JD. An examination of image and thought processes in generalized anxiety. Presented at the Association for the Advancement of Behavior Therapy; New York, NY: November 1991.
Odemuyiawa O, Malik M, Farrell T, Bashir Y, Poloniecki J, Camm J. Comparison of the predictive characteristics of heart rate variability index and left ventricular ejection fraction for all-cause mortality, arrhythmic events, and sudden death after acute myocardial infarction. Am J Cardiol. 1991;68:434-439.