Joint effect of hostility and severity of depressive symptoms on plasma interleukin-6 concentration.
OBJECTIVE
Although interleukin (IL)-6 plays a significant role in cardiovascular disease, little is known about its relation to psychological risk factors, such as hostility and severity of depressive symptoms. The current study examined the joint effects of severity of depressive symptoms and hostility on plasma IL-6 in a sample of 90 healthy, nonsmoking men.


METHODS
After an overnight fast, blood samples for plasma IL-6 and fasting lipids were collected on the same day that the Beck Depression Inventory (BDI) and the Cook-Medley hostility (Ho) scale were administered. Plasma IL-6 was determined using enzymatic-linked immunosorbent assay (ELISA).


RESULTS
Analyses of logarithmically normalized plasma IL-6 adjusting for age, body mass index (BMI), fasting total cholesterol, high density lipoprotein (HDL), and resting diastolic blood pressure (DBP) revealed a significant BDI by Ho interaction (p =.026). Post hoc decomposition revealed that Ho was correlated with log-normalized plasma IL-6 (r = 0.59, p =.025) but only among men with BDI scores of 10 and above. Alternatively, BDI was correlated with log-normalized plasma IL-6 (r = 0.61, p =.003) but only among men with Ho scores of 23 and higher. Comparisons among BDI/Ho groups indicated that men with high scores on both the BDI and the Ho exhibited the highest median levels of plasma IL-6.


CONCLUSIONS
Hostile men who exhibited above normal levels of depressive symptoms had higher plasma levels of IL-6 suggestive of a subpopulation at increased risk for future cardiac events.
Suarez
Edward C
EC
Department of Psychiatry and Behavioral Science, Duke University Medical Center, Durham, North Carolina 27710, USA. ecs.jr@duke.edu
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology; D003863:Depression / Q000097:blood*; D006791:Hostility; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011581:Psychological Tests; D012306:Risk; D012720:Severity of Illness Index
D015850:Interleukin-6; D008055:Lipids