Association between plasma inflammatory markers and irrational beliefs; the ATTICA epidemiological study

Recent research data suggest that inflammation and/or depression are associated with the development and progression of cardiovascular disease (CVD). Considering that depression may arise as a response to irrational beliefs according to the Ellis model of psychological disturbances and therapy, we sought to evaluate whether irrational beliefs are associated with plasma inflammatory factors in cardiovascular disease-free people. From May 2001 to December 2002 we randomly enrolled 453 men (23–69 years old) and 400 women (24–71 years old) stratified by age and gender. C-reactive protein, interleukin-6, serum amyloid-A, tumor necrosis factor-α and white blood cells were measured in all participants. Detailed dietary characteristics of these people were assessed through a validated food frequency questionnaire. Subjects completed also the irrational beliefs inventory (IBI), which is a brief self-report measure consistent with the Ellis model of psychological disturbance and therapy and the Zung's Depression questionnaire. The IBI scores were similar in men and women (53 ± 11 vs. 53 ± 10, p = 0.83). IBI score was positively correlated with C-reactive protein (rho = 0.14, p = 0. 02), interleukin-6 (rho = 0.11, p = 0.02), tumor necrosis factor-α (rho = 0.21, p = 0.014) and white blood cell counts (rho = 0.14, p = 0.02). These associations were confirmed even after adjusting for age, sex, years of school, body mass index, physical activity status, depression level and food items consumed by the participants. These findings indicate that irrational beliefs are associated with increased inflammation process, among apparently healthy individuals.