Inflammation, coagulation, and depressive symptomatology in cardiovascular disease-free people; the ATTICA study

BACKGROUND: Depression is associated with an increase in cardiovascular disease, but the underlying mechanisms are not well understood. The aim of this study was to examine the associations of depressive symptoms with inflammation and coagulation factors related to cardiovascular risk in persons free of cardiovascular disease. METHODS: A random algorithm was developed and stratified by gender-age and multistage sampling was performed during 2001-2002. In this study, we analysed data from 453 men (19-89 years old) and 400 women (18-84 years old). Inflammation markers were C-reactive protein (CRP), serum amyloid A, white blood cell (WBC) and total platelet counts; and coagulation factors including homocysteine and fibrinogen. Depression was assessed with the Zung Self-Rating Depression Scale (ZDRS range 0-100) after validation for the study population. A ZDRS score of 50 or more classified a person as mildly depressive. Statistical adjustments were made for risk factors (age, gender, smoking, diabetes mellitus, and physical activity level). RESULTS: Women had significantly higher scores on the Zung depression scale than men (47 +/- 9 vs. 43 +/- 10, p<0.001). Thus, 21% of men and 27% of women had mild depression, while 4% of men and 6% of women had severe depressive symptomatology. The depression scale correlated positively with C-reactive protein levels (p<0.05), white blood cell count (p<0.05), and fibrinogen (p<0.05) in both genders after adjustment for control variables. CONCLUSION: This study revealed that depression was associated with inflammation and coagulation factors in cardiovascular disease-free people, suggesting a possible pathway leading to an increased frequency of events of coronary heart disease in depressive individuals.