Religiosity and Cardiovascular Disease

Abstract & Commentary

By Howell Sasser, PhD. Dr. Sasser is Associate Professor of Epidemiology, New York Medical College, Valhalla, NY; he reports no financial relationship to this field of study.

Synopsis: Feinstein and colleagues assessed the association of religious activity with concurrent risk factors for cardiovascular disease, and with later adverse cardiovascular events. They found that those who were more religious were less likely to smoke and more likely to be obese, even after controlling for several other demographic factors. There was no apparent association in their population between religious practice and a reduction in cardiovascular risk.

Source: Feinstein M, et al. Burden of cardiovascular risk factors, subclinical atherosclerosis, and incident cardiovascular events across dimensions of religiosity: The multi-ethnic study of atherosclerosis. Circulation 2010;121:659-666.

A central question in the study of many behaviors that appear to have a beneficial effect on health is whether such behaviors make people healthier or simply are attractive to people who are healthier to begin with. This issue has been prominent in the study of religious practice as a modifier of health risk. A number of well-regarded studies have suggested that some aspect of religious activity promotes healthy behaviors and even reduces mortality.1,2 However, most studies to date have had difficulty determining whether such benefits derive in some way from religion or reflect the composition of the religiously active population, or perhaps from a combination of both.

Feinstein and colleagues add to the literature with a study that was designed to address aspects of this question. Their population, drawn from the Multi-Ethnic Study of Atherosclerosis (MESA), was geographically and racially diverse to permit inferences independent of regional or confessional characteristics. The study design included both cross-sectional and longitudinal elements to help in distinguishing between factors that individuals "brought" to their religious practices and the later impact of religion on health. The investigators also included multiple measures of religious activity rather than one, noting that religiousness is appropriately seen as a complex construct.

From the MESA cohort, 5,474 participants were included in the present study. All were between the ages of 48 and 84 years and free from cardiovascular disease (CVD) when enrolled. Caucasian and African-American participants were included in numbers slightly greater than their representation in the total MESA population; Chinese and Hispanic participants were slightly underrepresented. Anthropometric and behavioral risk factors, including smoking, obesity, diabetes, and hypertension, were collected at the same follow-up visit at which information about religious practices was collected. Measures of subclinical CVD were collected at baseline (coronary calcium score, carotid intima-media thickness, and left ventricular mass) and at a later visit (ankle brachial index). Religious practice was also assessed at this visit. Follow-up for new, clinically apparent cardiac events averaged 4.1 years, and collected information on death, myocardial infarction, and hospitalization for unstable angina.

Religious activity was defined by frequency of participation in public religious services, frequency of prayer or meditation, and "spirituality," as defined by responses to five questions drawn from the Daily Spiritual Experiences Scale. The participation and prayer measures were scored as Never/Once or Twice per Year/Monthly/Weekly/Daily, and the spirituality measure, summed over the five questions, as None/Low/Moderate/High.

The authors noted that results for the measures of religious attendance and prayer were very similar and presented only those for religious attendance. Participants who were more religiously active and those who reported higher levels of spirituality were more likely to be older, female, and African-American. They also were more likely to be obese and hypertensive, and less likely to smoke. The higher prevalence of obesity and lower prevalence of smoking among more intensely religious participants remained statistically significant after adjusting for demographic factors. More intensely religious participants also remained statistically more likely to be obese after adjusting for demographic factors and smoking status. No consistent and statistically significant associations of religious behavior with markers of subclinical CVD or new cardiac events were found.

Commentary

Feinstein et al provide mixed results, some of which confirm earlier findings and some of which do not. The higher prevalence of obesity and lower prevalence of smoking among more religiously active people are both well characterized.3,4 An interesting innovation in this respect is the finding that obesity is independent of other factors including smoking, prompted by the authors' observation that cigarette smoking has a role in appetite suppression. The finding of no association between religious activity and lower rates of negative health events is not in agreement with many earlier studies, but is also tied to a specific category of events, while prior studies often have used a more general model, such as all-cause mortality. This negative finding elicits from the authors relatively little discussion beyond a call for further research to determine whether their results can be replicated.

Readers should note several factors in the design of this study that have an impact on its interpretation. First, while the study collected a number of relevant demographic and lifestyle variables, it lacked measures of physical activity and of psychosocial stress, each of which is significant in heart disease, as well as in the most salient risk factors in this population — smoking and obesity. Stress is also hypothesized to be a mediating factor in the relationship of religious activity with health.5,6 These omissions leave open the possibility of unmeasured confounding.

Second, while the population was racially and ethnically diverse, it was arguably not religiously diverse. Inference from the ethnic make-up of the sample would suggest that it was mostly Christian with a small number of practitioners of East Asian religious and philosophical systems (Buddhism, Daoism, Confucianism). A wider range of religious traditions would be desirable, both to allow more stable comparisons and to represent the variety of expectations with respect to attendance at public religious activities and ways of expressing spirituality.

Third, to the study's credit, it collected several measures of subclinical disease. A chicken-and-egg dilemma in research on religious activity is the role of chronic, preclinical disease in motivating such behavior. If those with subclinical disease are more prone to adopt religious coping strategies, one might expect more clinically relevant later health events among religious people. This study showed some differences in preclinical CVD by level of religious activity, but no consistent pattern. This adds weight to the study's other findings.

Finally, this and all other studies of religion and health continue to grapple with how best to conceptualize and measure a complex concept that often is poorly explored, even at the individual level. The demand for quantification continues to favor the use of measures that permit uniform counting (i.e., how often) at the expense of measures of intensity. This leaves unanswered the basic question of whether religiousness is being measured — or even understood — correctly.

References

1. Strawbridge WJ, et al. Frequent attendance at religious services and mortality over 28 years. Am J Public Health 1997;87:957-961.

2. Koenig HG, et al. Does religious attendance prolong survival? A six-year follow-up study of 3,968 older adults. J Gerontol A Biol Sci Med Sci 1999;54: M370-M376.

3. Kim KH, et al. Religion and body weight. Int J Obesity Relat Metab Disord 2003;27:469-477.

4. Roff LL, et al. Religiosity, smoking, exercise, and obesity among Southern, community-dwelling older adults. J Appl Gerontol 2005;24:337-354.

5. Grippo AJ, Johnson AK. Stress, depression and cardiovascular dysregulation: A review of neurobiological mechanisms and the integration of research from preclinical disease models. Stress 2009;12:1-21.

6. Pargament KI, et al. Patterns of positive and negative religious coping with major life stressors. Journal for the Scientific Study of Religion 1998;37:710-724.