A Longitudinal Study of Stress, Alcohol, and Blood Pressure in Community-Based Samples of Blacks and Non-Blacks

Alcohol Research & Health, Winter, 1999 by Marcia Russell, M. Lynne Cooper, Michael R. Frone, Robert S. Peirce

Both alcohol use and stress appear to increase blood pressure. In addition, stress is associated with increased alcohol use. To investigate these relationships, researchers interviewed representative samples of the black and non-black adult household populations in Erie County, New York, in 1986, 1989, and 1993. The results support a causal relationship between stress and alcohol use and point to a number of factors that influence this relationship. Significant relationships between changes in alcohol use and blood pressure were also found. Although the researchers found little evidence for a direct effect of stress on blood pressure, stress related to family life, anxiety, and depression was associated with an increased risk for hypertension. KEY WORDS: African American; blood pressure; AOD (alcohol or other drug) use; psychological stress; New York; hypertensive disorder; emotional and psychiatric depression; anxiety state; coping skills; racial differences; gender differences; literature review; longitudin al study; survey

Epidemiologic studies strongly support the hypothesis that regular alcohol use above a poorly defined threshold is related to elevated blood pressure (Klatsky 1995). Other theories suggest that psychological stress affects hormone levels that are associated with elevated blood pressure (Henry et al. 1995). However, researchers believe that people increase their alcohol use to relieve tension or depression caused by exposure to stress and to things that cause stress (i.e., stressors). Thus, a key question to consider is the extent to which high blood pressure associated with psychological stress can be explained by increased alcohol use. Because the prevalence of hypertension is higher among blacks than among other ethnic groups, we were especially interested in determining whether racial differences influence the effects of stress and alcohol use on blood pressure.

Few longitudinal studies have examined factors influencing blood pressure among blacks, and no longitudinal studies have examined the joint effects of stress and alcohol use on blood pressure. Longitudinal studies, which follow participants over time to determine the sequence of events under investigation, are critical to establishing causal relationships between risk factors and outcomes.

This article summarizes findings from a longitudinal study funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) entitled Stress, Race, and Alcohol Use in a Household Population. The study was designed to examine the influence of stress and alcohol use on blood pressure and alcohol problems and to investigate racial differences in those relationships. The initial survey in 1986 was followed up in 1989 and 1993. Using data collected during the 7-year period enabled us to investigate the causal nature of the processes in question over time (i.e., longitudinally). The three surveys are referred to in this article as time 1, time 2, and time 3.

The study was based on a model (see figure, p. 300) of the effects of stress on alcohol use and the effects of both stress and alcohol use on alcohol abuse, alcohol dependence, and hypertension. As illustrated in the figure, the model proposed that stressors resulted in a stress response (i.e., negative feelings or a negative affect, such as depression, distress, or anxiety). The stress response appears to motivate a person to drink in an effort to cope with negative feelings, which, in turn, are exacerbated by increased alcohol use. Furthermore, sustained or habitual stress, drinking to cope, and increased alcohol use appear to cause, over an extended period of time, alcohol problems and hypertension. Because drinking tends to increase rather than relieve problems, the use of alcohol to cope with stressors is likely to increase a drinker's exposure to stressors over time. Furthermore, as a person's tolerance to alcohol develops, he or she drinks larger amounts of alcohol to achieve the same relief from nega tive feelings that he or she formerly achieved from consuming smaller alcohol doses. The inevitable result is a vicious cycle in which drinking to cope maintains and exacerbates alcohol problems.

Other factors also affect the stress process. Factors that increase the impact of a stressor on alcohol use are considered vulnerability factors, whereas factors that decrease the stressor's impact are considered buffering factors. Vulnerability and buffering factors examined in this study include positive alcohol expectancies (i.e., the belief that drinking alcohol will help one cope with stress), intrapersonal and interpersonal resources, coping styles, and demographic characteristics. These factors may directly affect exposure to stressors, stress responses, drinking to cope, and the outcomes illustrated in the figure, or they may moderate or influence the relationships among these elements. For example, we postulated that people who rated high on positive alcohol expectancies would drink more when exposed to stress than people who rated low on positive alcohol expectancies. Thus, positive alcohol expectancies would act as a vulnerability factor that moderated the relationship between stressors and alcoho l use. Several psychological theories of drinking and alcoholism contributed to the development of this model (Blane and Leonard 1987).