NTERNATIONAL R EVIEW OF I NDUSTRIAL AND O RGANIZATIONAL P SYCHOLOGY 2005 burnout seems to involve enhancedinflammatory responses andoxidative

288 I NTERNATIONAL R EVIEW OF I NDUSTRIAL AND O RGANIZATIONAL P SYCHOLOGY 2005 burnout seems to involve enhancedinflammatory responses andoxidative

stress. An association between VE andserological markers of inflammation was observedin a study by Appels andhis associates (Appels, Bar et al., 2000) which was conducted among patients treated with directional coronary angioplasty because of severe angina. The results showedexhaustedor

or depressed (this study’s design did not allow the researchers to distinguish between depressed and burned-out patients). In a second study of persons over 65 years old, VE was associated with albumin, fibrinogen, C-reactive protein, andWBC (Kop et al., 2002). No such association with depression was found after adjusting for several control variables. This second study also supportedprevious observations of interrelations between coagulation, fibrinolytic, andinflammatory processes (Kop et al., 2002). In a longitudinal study of 102 healthy males, high levels of s-prolactin, an endocrine measure of long-term exposure to stress, predicted VE (Halford et al., 2003). Thus, by implication burnout may be associatedwith CVD risk through the presence of smoldering inflammation. This hypothesis awaits further confirmation, or refutation, through more extensive research.

The above evidence gives rise to the hypothesis that burnout may be implicatedin the acute phase response. The acute phase response, which may follow either stress or infection, includes physiological, behavioral, mood, and cognitive adjustments (Maier & Watkins, 1998). Among these adjustments are increased levels of pro-inflammatory cytokines; reduction in activity, social interaction, andsexual behavior; d epressive symptoms; andinterference with certain types of memory andactivation of the HPA system (Maier & Watkins, 1998). Some of those symptoms overlap with the core contents of burnout; namely, emotional, cognitive andphysical depletion of energy.

Burnout and the immune system Burnout may have a negative effect on the immune system andconsequently

elevate inflammation biomarkers andincrease the incidence of infections. In

a study of 42 male office workers, one of the MBI’s components, deperson- alization, was foundto be associatedwith reducedcellular immunity (lower Natural Killer (NK) cell activity andlower proportionality of CD57 þ CD16 to total lymphocytes. This was independent of health behaviors (e.g., smoking, alcohol use, obesity) or work stress (Nakamura, Nagase, Yoshida, & Ogino, 1999). The study by Mohren et al. (2003) provides strong evidence for burnout as a risk factor for common infections in a large heterogeneous population. Taken together with the previous set of findings reported by Nakamura et al. (1999), we are ledto suggest that burned-out persons may

B URNOUT AND H EALTH R EVIEW

be at risk of reduced immuno-competence and may be potentially prone to a variety of infectious diseases such as upper respiratory infections and differ- ent types of viral infections. Again, this may be an important avenue for future research, since not all studies support this conclusion. In a cross- sectional study of 71 physicians, a team of Italian researchers (Bargellini et al., 2000) failedto findany relationship between a host of immune variables andtwo components of the MBI, emotional exhaustion andcynicism, but did findthe thirdcomponent, personal accomplishment, to be significantly associatedwith these participants’ immune profiles. It is of interest to note that immune dysfunction in patients with Chronic Fatigue Syndrome (CFS) has been widely but inconsistently reported in past research. A recent meta- analysis of the evidence (Lyall, Peakman, & Wessely, 2003) reached the conclusion that no consistent pattern of immunological abnormalities could

be identified in CFS patients. Health behaviors

Schaufeli andEnzmann (1998, p. 88) were able to findfour studies that have investigatedthe linkages among health behaviors (coffee consumption, alcohol consumption, calorie intake, substance abuse, andsmoking) and emotional exhaustion (as measuredin the MBI), andall of them reported null or very small correlations. We were able to findtwo recent studies, both of dentists, in different countries, that found significant correlations between alcohol consumption andemotional exhaustion or burnout (Gorter et al., 2000; Winwood, Winefield, & Lushington, 2003). Melamed et al. (1992), in a study of 104 disease-free male employees in the high-tech industry, foundthat a high level of tense burnout was associatedwith poor health habits, including smoking and lack of participation in physical leisure activities, which is consistent with the findings of Gorter et al. (2000). However, the findings of Melamed et al. (1992) linking burnout and health behaviors were basedon very small andunrepresentative samples. Therefore, the relationship among health-relatedbehaviors andburnout appears to be an area in need of additional research. The evidence at hand does not support viewing health behaviors as either moderating or mediating the relationship between burnout andhealth.

Taken together, the findings of the above studies suggest that burnout may

be associatedwith CVD risk through multiple pathways: sleep disturbances, increasedbiochemical risk factors, inflammation, andperhaps also reduced immuno-competence.